Leibniz Transactions On Embedded Systems
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Gottfried Wilhelm Leibniz (or Leibnitz; – 14 November 1716) was a German
polymath A polymath or polyhistor is an individual whose knowledge spans many different subjects, known to draw on complex bodies of knowledge to solve specific problems. Polymaths often prefer a specific context in which to explain their knowledge, ...
active as a
mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...
,
philosopher Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...
,
scientist A scientist is a person who Scientific method, researches to advance knowledge in an Branches of science, area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engag ...
and
diplomat A diplomat (from ; romanization, romanized ''diploma'') is a person appointed by a state (polity), state, International organization, intergovernmental, or Non-governmental organization, nongovernmental institution to conduct diplomacy with one ...
who is credited, alongside
Sir Isaac Newton Sir Isaac Newton () was an English polymath active as a mathematician, physicist, astronomer, alchemist, theologian, and author. Newton was a key figure in the Scientific Revolution and the Enlightenment that followed. His book (''Mathe ...
, with the creation of
calculus Calculus is the mathematics, mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithmetic operations. Originally called infinitesimal calculus or "the ...
in addition to many other branches of
mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...
, such as binary arithmetic and
statistics Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a s ...
. Leibniz has been called the "last universal genius" due to his vast expertise across fields, which became a rarity after his lifetime with the coming of the Industrial Revolution and the spread of specialized labor. He is a prominent figure in both the
history of philosophy The history of philosophy is the systematic study of the development of philosophical thought. It focuses on philosophy as rational inquiry based on argumentation, but some theorists also include myth, religious traditions, and proverbial lor ...
and the
history of mathematics The history of mathematics deals with the origin of discoveries in mathematics and the History of mathematical notation, mathematical methods and notation of the past. Before the modern age and the worldwide spread of knowledge, written examples ...
. He wrote works on
philosophy Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...
,
theology Theology is the study of religious belief from a Religion, religious perspective, with a focus on the nature of divinity. It is taught as an Discipline (academia), academic discipline, typically in universities and seminaries. It occupies itse ...
,
ethics Ethics is the philosophy, philosophical study of Morality, moral phenomena. Also called moral philosophy, it investigates Normativity, normative questions about what people ought to do or which behavior is morally right. Its main branches inclu ...
,
politics Politics () is the set of activities that are associated with decision-making, making decisions in social group, groups, or other forms of power (social and political), power relations among individuals, such as the distribution of Social sta ...
,
law Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior, with its precise definition a matter of longstanding debate. It has been variously described as a science and as the ar ...
,
history History is the systematic study of the past, focusing primarily on the Human history, human past. As an academic discipline, it analyses and interprets evidence to construct narratives about what happened and explain why it happened. Some t ...
,
philology Philology () is the study of language in Oral tradition, oral and writing, written historical sources. It is the intersection of textual criticism, literary criticism, history, and linguistics with strong ties to etymology. Philology is also de ...
,
games A game is a Structure, structured type of play (activity), play usually undertaken for entertainment or fun, and sometimes used as an Educational game, educational tool. Many games are also considered to be Work (human activity), work (such as p ...
,
music Music is the arrangement of sound to create some combination of Musical form, form, harmony, melody, rhythm, or otherwise Musical expression, expressive content. Music is generally agreed to be a cultural universal that is present in all hum ...
, and other studies. Leibniz also made major contributions to
physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...
and
technology Technology is the application of Conceptual model, conceptual knowledge to achieve practical goals, especially in a reproducible way. The word ''technology'' can also mean the products resulting from such efforts, including both tangible too ...
, and anticipated notions that surfaced much later in
probability theory Probability theory or probability calculus is the branch of mathematics concerned with probability. Although there are several different probability interpretations, probability theory treats the concept in a rigorous mathematical manner by expre ...
,
biology Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...
,
medicine Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...
,
geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
,
psychology Psychology is the scientific study of mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both consciousness, conscious and Unconscious mind, unconscious phenomena, and mental processes such as thoughts, feel ...
,
linguistics Linguistics is the scientific study of language. The areas of linguistic analysis are syntax (rules governing the structure of sentences), semantics (meaning), Morphology (linguistics), morphology (structure of words), phonetics (speech sounds ...
and
computer science Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, ...
. Leibniz contributed to the field of
library science Library and information science (LIS)Library and Information Sciences is the name used in the Dewey Decimal Classification for class 20 from the 18th edition (1971) to the 22nd edition (2003). are two interconnected disciplines that deal with info ...
, developing a cataloguing system (at the
Herzog August Library The Herzog August Library ( — "HAB"), in Wolfenbüttel, Lower Saxony, known also as ''Bibliotheca Augusta'', is a library of international importance for its collection from the Middle Ages and early modern Europe. The library is overseen ...
in
Wolfenbüttel Wolfenbüttel (; ) is a town in Lower Saxony, Germany, the administrative capital of Wolfenbüttel District Wolfenbüttel (; ) is a town in Lower Saxony, Germany, the administrative capital of Wolfenbüttel (district), Wolfenbüttel Distri ...
, Germany) that came to serve as a model for many of Europe's largest libraries. His contributions to a wide range of subjects were scattered in various
learned journal An academic journal (or scholarly journal or scientific journal) is a periodical publication in which scholarship relating to a particular academic discipline is published. They serve as permanent and transparent forums for the dissemination, scr ...
s, in tens of thousands of letters and in unpublished manuscripts. He wrote in several languages, primarily in Latin, French and German. As a philosopher, he was a leading representative of 17th-century
rationalism In philosophy, rationalism is the Epistemology, epistemological view that "regards reason as the chief source and test of knowledge" or "the position that reason has precedence over other ways of acquiring knowledge", often in contrast to ot ...
and
idealism Idealism in philosophy, also known as philosophical realism or metaphysical idealism, is the set of metaphysics, metaphysical perspectives asserting that, most fundamentally, reality is equivalent to mind, Spirit (vital essence), spirit, or ...
. As a mathematician, his major achievement was the development of differential and integral calculus, independently of Newton's contemporaneous developments.
Leibniz's notation In calculus, Leibniz's notation, named in honor of the 17th-century German philosopher and mathematician Gottfried Wilhelm Leibniz, uses the symbols and to represent infinitely small (or infinitesimal) increments of and , respectively, just a ...
has been favored as the conventional and more exact expression of calculus. In addition to his work on calculus, he is credited with devising the modern
binary number A binary number is a number expressed in the Radix, base-2 numeral system or binary numeral system, a method for representing numbers that uses only two symbols for the natural numbers: typically "0" (zero) and "1" (one). A ''binary number'' may ...
system, which is the basis of modern communications and digital computing; however,
Thomas Harriot Thomas Harriot (; – 2 July 1621), also spelled Harriott, Hariot or Heriot, was an English astronomer, mathematician, ethnographer and translator to whom the theory of refraction is attributed. Thomas Harriot was also recognized for his con ...
had devised the same system decades before. He envisioned the field of
combinatorial topology In mathematics, combinatorial topology was an older name for algebraic topology, dating from the time when topological invariants of spaces (for example the Betti numbers) were regarded as derived from combinatorial decompositions of spaces, such a ...
as early as 1679, and helped initiate the field of
fractional calculus Fractional calculus is a branch of mathematical analysis that studies the several different possibilities of defining real number powers or complex number powers of the differentiation operator D D f(x) = \frac f(x)\,, and of the integration ...
. In the 20th century, Leibniz's notions of the
law of continuity Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior, with its precise definition a matter of longstanding debate. It has been variously described as a science and as the ar ...
and the
transcendental law of homogeneity In mathematics, the transcendental law of homogeneity (TLH) is a heuristic principle enunciated by Gottfried Wilhelm Leibniz most clearly in a 1710 text entitled ''Symbolismus memorabilis calculi algebraici et infinitesimalis in comparatione potent ...
found a consistent mathematical formulation by means of
non-standard analysis The history of calculus is fraught with philosophical debates about the meaning and logical validity of fluxions or infinitesimal numbers. The standard way to resolve these debates is to define the operations of calculus using (ε, δ)-definitio ...
. He was also a pioneer in the field of
mechanical calculator A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or a simulation like an analog computer or a slide rule. Most mechanical calculators were comparable in si ...
s. While working on adding automatic multiplication and division to
Pascal's calculator A Pascaline signed by Pascal in 1652 Top view and overview of the entire mechanism. This version of Pascaline was for accounting. The pascaline (also known as the arithmetic machine or Pascal's calculator) is a mechanical calculator invented by ...
, he was the first to describe a
pinwheel calculator A pinwheel calculator is a class of mechanical calculator described as early as 1685, and popular in the 19th and 20th century, calculating via wheels whose number of teeth were adjustable. These wheels, also called pinwheels, could be set by usi ...
in 1685 and invented the
Leibniz wheel A Leibniz wheel or stepped drum is a cylinder with a set of teeth of incremental lengths which, when coupled to a counting wheel, can be used in the calculating engine of a class of mechanical calculators. Invented by Leibniz in 1673, it was used ...
, later used in the
arithmometer The arithmometer () was the first digital data, digital mechanical calculator strong and reliable enough to be used daily in an office environment. This calculator could add and subtract two numbers directly and perform Multiplication algorithm, ...
, the first mass-produced mechanical calculator. In
philosophy Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...
and
theology Theology is the study of religious belief from a Religion, religious perspective, with a focus on the nature of divinity. It is taught as an Discipline (academia), academic discipline, typically in universities and seminaries. It occupies itse ...
, Leibniz is most noted for his
optimism Optimism is the Attitude (psychology), attitude or mindset of expecting events to lead to particularly positive, favorable, desirable, and hopeful outcomes. A common idiom used to illustrate optimism versus pessimism is Is the glass half empty ...
, i.e. his conclusion that our world is, in a qualified sense, the best possible world that
God In monotheistic belief systems, God is usually viewed as the supreme being, creator, and principal object of faith. In polytheistic belief systems, a god is "a spirit or being believed to have created, or for controlling some part of the un ...
could have created, a view sometimes lampooned by other thinkers, such as
Voltaire François-Marie Arouet (; 21 November 169430 May 1778), known by his ''Pen name, nom de plume'' Voltaire (, ; ), was a French Age of Enlightenment, Enlightenment writer, philosopher (''philosophe''), satirist, and historian. Famous for his wit ...
in his
satirical Satire is a genre of the visual arts, visual, literature, literary, and performing arts, usually in the form of fiction and less frequently Nonfiction, non-fiction, in which vices, follies, abuses, and shortcomings are held up to ridicule, ...
novella A novella is a narrative prose fiction whose length is shorter than most novels, but longer than most novelettes and short stories. The English word ''novella'' derives from the Italian meaning a short story related to true (or apparently so) ...
''
Candide ( , ) is a French satire written by Voltaire, a philosopher of the Age of Enlightenment, first published in 1759. The novella has been widely translated, with English versions titled ''Candide: or, All for the Best'' (1759); ''Candide: or, The ...
''. Leibniz, along with
René Descartes René Descartes ( , ; ; 31 March 1596 – 11 February 1650) was a French philosopher, scientist, and mathematician, widely considered a seminal figure in the emergence of modern philosophy and Modern science, science. Mathematics was paramou ...
and
Baruch Spinoza Baruch (de) Spinoza (24 November 163221 February 1677), also known under his Latinized pen name Benedictus de Spinoza, was a philosopher of Portuguese-Jewish origin, who was born in the Dutch Republic. A forerunner of the Age of Enlightenmen ...
, was one of the three influential early modern
rationalists In philosophy, rationalism is the epistemological view that "regards reason as the chief source and test of knowledge" or "the position that reason has precedence over other ways of acquiring knowledge", often in contrast to other possible s ...
. His philosophy also assimilates elements of the scholastic tradition, notably the assumption that some substantive knowledge of reality can be achieved by reasoning from first principles or prior definitions. The work of Leibniz anticipated modern
logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o ...
and still influences contemporary
analytic philosophy Analytic philosophy is a broad movement within Western philosophy, especially English-speaking world, anglophone philosophy, focused on analysis as a philosophical method; clarity of prose; rigor in arguments; and making use of formal logic, mat ...
, such as its adopted use of the term "
possible world A possible world is a complete and consistent way the world is or could have been. Possible worlds are widely used as a formal device in logic, philosophy, and linguistics in order to provide a semantics for intensional and modal logic. Their met ...
" to define modal notions.


Biography


Early life

Gottfried Leibniz was born on 1 July 1646, in
Leipzig Leipzig (, ; ; Upper Saxon: ; ) is the most populous city in the States of Germany, German state of Saxony. The city has a population of 628,718 inhabitants as of 2023. It is the List of cities in Germany by population, eighth-largest city in Ge ...
, Saxony, to Friedrich Leibniz (1597–1652) and Catharina Schmuck (1621–1664). He was baptized two days later at
St. Nicholas Church, Leipzig The St. Nicholas Church () is one of the major churches of central Leipzig, Germany (in Leipzig's district Mitte). Construction started in Romanesque style in 1165, but in the 16th century, the church was turned into a Gothic hall church. Baro ...
; his godfather was the
Lutheran Lutheranism is a major branch of Protestantism that emerged under the work of Martin Luther, the 16th-century German friar and Protestant Reformers, reformer whose efforts to reform the theology and practices of the Catholic Church launched ...
theologian . His father died when he was six years old, and Leibniz was raised by his mother. Leibniz's father had been a Professor of Moral Philosophy at the
University of Leipzig Leipzig University (), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December 1409 by Frederick I, Electo ...
, where he also served as dean of philosophy. The boy inherited his father's personal library. He was given free access to it from the age of seven, shortly after his father's death. While Leibniz's schoolwork was largely confined to the study of a small
canon Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the material accepted as officially written by an author or an ascribed author * Literary canon, an accepted body of works considered as high culture ** Western canon, th ...
of authorities, his father's library enabled him to study a wide variety of advanced philosophical and theological works—ones that he would not have otherwise been able to read until his college years. Access to his father's library, largely written in
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
, also led to his proficiency in the Latin language, which he achieved by the age of 12. At the age of 13 he composed 300
hexameters Hexameter is a Metre (poetry), metrical Line (poetry), line of verses consisting of six metrical foot, feet (a "foot" here is the pulse, or major accent, of words in an English language, English line of poetry; in Greek language, Greek as well as i ...
of Latin verse in a single morning for a special event at school. In April 1661 he enrolled in his father's former university at age 14. There he was guided, among others, by
Jakob Thomasius Jakob Thomasius (; ; 27 August 1622 – 9 September 1684) was a German academic philosopher and jurist. He is now regarded as an important founding figure in the scholarly study of the history of philosophy. His views were eclectic, and were tak ...
, previously a student of Friedrich. Leibniz completed his
bachelor's degree A bachelor's degree (from Medieval Latin ''baccalaureus'') or baccalaureate (from Modern Latin ''baccalaureatus'') is an undergraduate degree awarded by colleges and universities upon completion of a course of study lasting three to six years ...
in Philosophy in December 1662. He defended his ''Disputatio Metaphysical de Principio Individual'' (''Metaphysical Disputation on the Principle of Individuation''),Arthur 2014, p. x. which addressed the
principle of individuation The principle of individuation is a criterion that individuates or numerically distinguishes the members of the kind for which it is given, that is by which we can supposedly determine, regarding any kind of thing, when we have more than one of the ...
, on , presenting an early version of monadic substance theory. Leibniz earned his
master's degree A master's degree (from Latin ) is a postgraduate academic degree awarded by universities or colleges upon completion of a course of study demonstrating mastery or a high-order overview of a specific field of study or area of professional prac ...
in Philosophy on 7 February 1664. In December 1664 he published and defended a dissertation ''Specimen Quaestionum Philosophicarum ex Jure collectarum'' (''An Essay of Collected Philosophical Problems of Right''), arguing for both a theoretical and a pedagogical relationship between philosophy and law. After one year of legal studies, he was awarded his bachelor's degree in Law on 28 September 1665. His dissertation was titled ''De conditionibus'' (''On Conditions''). In early 1666, at age 19, Leibniz wrote his first book, ''
De Arte Combinatoria The ''Dissertatio de arte combinatoria'' ("Dissertation on the Art of Combinations" or "On the Combinatorial Art") is an early work by Gottfried Leibniz published in 1666 in Leipzig. It is an extended version of his first doctoral dissertation, wr ...
'' (''On the Combinatorial Art''), the first part of which was also his
habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in Germany, France, Italy, Poland and some other European and non-English-speaking countries. The candidate fulfills a university's set criteria of excelle ...
thesis in Philosophy, which he defended in March 1666. ''De Arte Combinatoria'' was inspired by
Ramon Llull Ramon Llull (; ; – 1316), sometimes anglicized as ''Raymond Lully'', was a philosopher, theologian, poet, missionary, Christian apologist and former knight from the Kingdom of Majorca. He invented a philosophical system known as the ''Art ...
's '' Ars Magna'' and contained a
proof of the existence of God The existence of God is a subject of debate in the philosophy of religion and theology. A wide variety of arguments for and against the existence of God (with the same or similar arguments also generally being used when talking about the exis ...
, cast in geometrical form, and based on the
argument from motion In the philosophy of religion, a cosmological argument is an argument for the existence of God based upon observational and factual statements concerning the universe (or some general category of its natural contents) typically in the context of ...
. His next goal was to earn his license and Doctorate in Law, which normally required three years of study. In 1666, the University of Leipzig turned down Leibniz's doctoral application and refused to grant him a Doctorate in Law, most likely due to his relative youth. Leibniz subsequently left Leipzig. Leibniz then enrolled in the
University of Altdorf The University of Altdorf () was a university in Altdorf bei Nürnberg, a small town outside the Free Imperial City of Nuremberg. It was founded in 1578 and received university privileges in 1622 and was closed in 1809 by Maximilian I Joseph of Ba ...
and quickly submitted a thesis, which he had probably been working on earlier in Leipzig. The title of his thesis was ''Disputatio Inauguralis de Casibus Perplexis in Jure'' (''Inaugural Disputation on Ambiguous Legal Cases''). Leibniz earned his license to practice law and his Doctorate in Law in November 1666. He next declined the offer of an academic appointment at Altdorf, saying that "my thoughts were turned in an entirely different direction". As an adult, Leibniz often introduced himself as "Gottfried
von The term () is used in German surnames either as a nobiliary particle indicating a noble patrilineality, or as a simple preposition used by commoners that means or . Nobility directories like the often abbreviate the noble term to ''v.'' ...
Leibniz". Many posthumously published editions of his writings presented his name on the title page as "
Freiherr (; male, abbreviated as ), (; his wife, abbreviated as , ) and (, his unmarried daughters and maiden aunts) are designations used as titles of nobility in the German-speaking areas of the Holy Roman Empire, the Austro-Hungarian Empire and in ...
G. W. von Leibniz." However, no document has ever been found from any contemporary government that stated his appointment to any form of
nobility Nobility is a social class found in many societies that have an aristocracy. It is normally appointed by and ranked immediately below royalty. Nobility has often been an estate of the realm with many exclusive functions and characteristics. T ...
.


1666–1676

Leibniz's first position was as a salaried secretary to an
alchemical Alchemy (from the Arabic word , ) is an ancient branch of natural philosophy, a philosophical and protoscientific tradition that was historically practised in China, India, the Muslim world, and Europe. In its Western form, alchemy is first ...
society in
Nuremberg Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...
. He knew fairly little about the subject at that time but presented himself as deeply learned. He soon met
Johann Christian von Boyneburg Johann Christian von Boyneburg (April 12, 1622 - December 8, 1672) was a German politician. Life Johann Christian von Boyneburg was born into a family whose members had often been in the official Hessian state service. His father was the counci ...
(1622–1672), the dismissed chief minister of the
Elector Elector may refer to: * Prince-elector or elector, a member of the electoral college of the Holy Roman Empire, having the function of electing the Holy Roman Emperors * Elector, a member of an electoral college ** Confederate elector, a member of t ...
of
Mainz Mainz (; #Names and etymology, see below) is the capital and largest city of the German state of Rhineland-Palatinate, and with around 223,000 inhabitants, it is List of cities in Germany by population, Germany's 35th-largest city. It lies in ...
,
Johann Philipp von Schönborn Johann, typically a male given name, is the German form of ''Iohannes'', which is the Latin form of the Greek name ''Iōánnēs'' (), itself derived from Hebrew name '' Yochanan'' () in turn from its extended form (), meaning "Yahweh is Gracious ...
. Von Boyneburg hired Leibniz as an assistant, and shortly thereafter reconciled with the Elector and introduced Leibniz to him. Leibniz then dedicated an essay on law to the Elector in the hope of obtaining employment. The stratagem worked; the Elector asked Leibniz to assist with the redrafting of the legal code for the Electorate. In 1669, Leibniz was appointed assessor in the Court of Appeal. Although von Boyneburg died late in 1672, Leibniz remained under the employment of his widow until she dismissed him in 1674. Von Boyneburg did much to promote Leibniz's reputation, and the latter's memoranda and letters began to attract favorable notice. After Leibniz's service to the Elector there soon followed a diplomatic role. He published an essay, under the pseudonym of a fictitious Polish nobleman, arguing (unsuccessfully) for the German candidate for the Polish crown. The main force in European geopolitics during Leibniz's adult life was the ambition of
Louis XIV of France LouisXIV (Louis-Dieudonné; 5 September 16381 September 1715), also known as Louis the Great () or the Sun King (), was King of France from 1643 until his death in 1715. His verified reign of 72 years and 110 days is the List of longest-reign ...
, backed by French military and economic might. Meanwhile, the
Thirty Years' War The Thirty Years' War, fought primarily in Central Europe between 1618 and 1648, was one of the most destructive conflicts in History of Europe, European history. An estimated 4.5 to 8 million soldiers and civilians died from battle, famine ...
had left
German-speaking Europe This article details the geographical distribution of speakers of the German language, regardless of the legislative status within the countries where it is spoken. In addition to the Germanosphere () in Europe, German-speaking minority languag ...
exhausted, fragmented, and economically backward. Leibniz proposed to protect German-speaking Europe by distracting Louis as follows: France would be invited to take
Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...
as a stepping stone towards an eventual conquest of the
Dutch East Indies The Dutch East Indies, also known as the Netherlands East Indies (; ), was a Dutch Empire, Dutch colony with territory mostly comprising the modern state of Indonesia, which Proclamation of Indonesian Independence, declared independence on 17 Au ...
. In return, France would agree to leave Germany and the Netherlands undisturbed. This plan obtained the Elector's cautious support. In 1672, the French government invited Leibniz to Paris for discussion, but the plan was soon overtaken by the outbreak of the
Franco-Dutch War The Franco-Dutch War, 1672 to 1678, was primarily fought by Kingdom of France, France and the Dutch Republic, with both sides backed at different times by a variety of allies. Related conflicts include the 1672 to 1674 Third Anglo-Dutch War and ...
and became irrelevant. Napoleon's failed invasion of Egypt in 1798 can be seen as an unwitting, late implementation of Leibniz's plan, after the Eastern hemisphere colonial supremacy in Europe had already passed from the Dutch to the British. Thus Leibniz went to Paris in 1672. Soon after arriving, he met Dutch physicist and mathematician
Christiaan Huygens Christiaan Huygens, Halen, Lord of Zeelhem, ( , ; ; also spelled Huyghens; ; 14 April 1629 – 8 July 1695) was a Dutch mathematician, physicist, engineer, astronomer, and inventor who is regarded as a key figure in the Scientific Revolution ...
and realised that his own knowledge of mathematics and physics was patchy. With Huygens as his mentor, he began a program of
self-study Autodidacticism (also autodidactism) or self-education (also self-learning, self-study and self-teaching) is the practice of education without the guidance of schoolmasters (i.e., teachers, professors, institutions). Overview Autodida ...
that soon pushed him to making major contributions to both subjects, including discovering his version of the differential and integral
calculus Calculus is the mathematics, mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithmetic operations. Originally called infinitesimal calculus or "the ...
. He met
Nicolas Malebranche Nicolas Malebranche ( ; ; 6 August 1638 – 13 October 1715) was a French Oratorian Catholic priest and rationalist philosopher. In his works, he sought to synthesise the thought of St. Augustine and Descartes, in order to demonstrate the ...
and
Antoine Arnauld Antoine Arnauld (; 6 February 16128 August 1694) was a French Catholic theologian, priest, philosopher and mathematician. He was one of the leading intellectuals of the Jansenist group of Port-Royal and had a very thorough knowledge of patr ...
, the leading French philosophers of the day, and studied the writings of Descartes and Pascal, unpublished as well as published. He befriended a German mathematician,
Ehrenfried Walther von Tschirnhaus Ehrenfried Walther von Tschirnhaus or Tschirnhauß (; 10 April 1651 – 11 October 1708) was a German mathematician, physicist, physician, and philosopher. He introduced the Tschirnhaus transformation and is considered by some to have been the ...
; they corresponded for the rest of their lives. When it became clear that France would not implement its part of Leibniz's Egyptian plan, the Elector sent his nephew, escorted by Leibniz, on a related mission to the English government in London, early in 1673. There Leibniz came into acquaintance of
Henry Oldenburg Henry Oldenburg (also Henry Oldenbourg) (c. 1618 as Heinrich Oldenburg – 5 September 1677) was a German theologian, diplomat, and natural philosopher, known as one of the creators of modern scientific peer review. He was one of the foremos ...
and John Collins. He met with the
Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
where he demonstrated a calculating machine that he had designed and had been building since 1670. The machine was able to execute all four basic operations (adding, subtracting, multiplying, and dividing), and the society quickly made him an external member. The mission ended abruptly when news of the Elector's death (12 February 1673) reached them. Leibniz promptly returned to Paris and not, as had been planned, to Mainz. The sudden deaths of his two patrons in the same winter meant that Leibniz had to find a new basis for his career. In this regard, a 1669 invitation from Duke John Frederick of Brunswick to visit Hanover proved to have been fateful. Leibniz had declined the invitation, but had begun corresponding with the duke in 1671. In 1673, the duke offered Leibniz the post of counsellor. Leibniz very reluctantly accepted the position two years later, only after it became clear that no employment was forthcoming in Paris, whose intellectual stimulation he relished, or with the
Habsburg The House of Habsburg (; ), also known as the House of Austria, was one of the most powerful dynasties in the history of Europe and Western civilization. They were best known for their inbreeding and for ruling vast realms throughout Europe d ...
imperial court. In 1675 he tried to get admitted to the
French Academy of Sciences The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
as a foreign honorary member, but it was considered that there were already enough foreigners there and so no invitation came. He left Paris in October 1676.


House of Hanover, 1676–1716

Leibniz managed to delay his arrival in Hanover until the end of 1676 after making one more short journey to London, where Newton accused him of having seen his unpublished work on calculus in advance. This was alleged to be evidence supporting the accusation, made decades later, that he had stolen calculus from Newton. On the journey from London to Hanover, Leibniz stopped in
The Hague The Hague ( ) is the capital city of the South Holland province of the Netherlands. With a population of over half a million, it is the third-largest city in the Netherlands. Situated on the west coast facing the North Sea, The Hague is the c ...
where he met van Leeuwenhoek, the discoverer of microorganisms. He also spent several days in intense discussion with
Spinoza Baruch (de) Spinoza (24 November 163221 February 1677), also known under his Latinized pen name Benedictus de Spinoza, was a philosopher of Portuguese-Jewish origin, who was born in the Dutch Republic. A forerunner of the Age of Enlightenmen ...
, who had just completed, but had not published, his masterwork, the ''
Ethics Ethics is the philosophy, philosophical study of Morality, moral phenomena. Also called moral philosophy, it investigates Normativity, normative questions about what people ought to do or which behavior is morally right. Its main branches inclu ...
''. Spinoza died very shortly after Leibniz's visit. In 1677, he was promoted, at his request, to Privy Counselor of Justice, a post he held for the rest of his life. Leibniz served three consecutive rulers of the House of Brunswick as historian, political adviser, and most consequentially, as librarian of the
ducal Duke is a male title either of a monarch ruling over a duchy, or of a member of royalty, or nobility. As rulers, dukes are ranked below emperors, kings, grand princes, grand dukes, and above sovereign princes. As royalty or nobility, they are ...
library. He thenceforth employed his pen on all the various political, historical, and
theological Theology is the study of religious belief from a religious perspective, with a focus on the nature of divinity. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of an ...
matters involving the House of Brunswick; the resulting documents form a valuable part of the historical record for the period. Leibniz began promoting a project to use windmills to improve the mining operations in the Harz Mountains. This project did little to improve mining operations and was shut down by Duke Ernst August in 1685. Among the few people in north Germany to accept Leibniz were the Electress
Sophia of Hanover Sophia (born Princess Sophia of the Palatinate; – ) was Electress of Hanover from 19 December 1692 until 23 January 1698 as the consort of Prince-Elector Ernest Augustus. She was later the heiress presumptive to the thrones of England and ...
(1630–1714), her daughter
Sophia Charlotte of Hanover Sophia Charlotte of Hanover (30 October 1668 – 1 February 1705) was the first Queen consort in Prussia as the wife of King Frederick I. She was the only daughter of Elector Ernest Augustus of Hanover and Sophia of the Palatinate. Her eldes ...
(1668–1705), the Queen of Prussia and his avowed disciple, and
Caroline of Ansbach Caroline of Brandenburg-Ansbach (Wilhelmina Charlotte Caroline; 1 March 1683 – 20 November 1737) was List of British royal consorts, Queen of Great Britain and Ireland and List of Hanoverian royal consorts, Electress of Hanover from 11 J ...
, the consort of her grandson, the future George II. To each of these women he was correspondent, adviser, and friend. In turn, they all approved of Leibniz more than did their spouses and the future king
George I of Great Britain George I (George Louis; ; 28 May 1660 – 11 June 1727) was King of Great Britain and King of Ireland, Ireland from 1 August 1714 and ruler of the Electorate of Hanover within the Holy Roman Empire from 23 January 1698 until his death in 1727. ...
. The population of Hanover was only about 10,000, and its provinciality eventually grated on Leibniz. Nevertheless, to be a major courtier to the House of Brunswick was quite an honor, especially in light of the meteoric rise in the prestige of that House during Leibniz's association with it. In 1692, the Duke of Brunswick became a hereditary Elector of the
Holy Roman Empire The Holy Roman Empire, also known as the Holy Roman Empire of the German Nation after 1512, was a polity in Central and Western Europe, usually headed by the Holy Roman Emperor. It developed in the Early Middle Ages, and lasted for a millennium ...
. The British
Act of Settlement 1701 The Act of Settlement ( 12 & 13 Will. 3. c. 2) is an act of the Parliament of England that settled the succession to the English and Irish crowns to only Protestants, which passed in 1701. More specifically, anyone who became a Roman Catho ...
designated the Electress Sophia and her descent as the royal family of England, once both King
William III William III or William the Third may refer to: Kings * William III of Sicily () * William III of England and Ireland or William III of Orange or William II of Scotland (1650–1702) * William III of the Netherlands and Luxembourg (1817–1890) N ...
and his sister-in-law and successor, Queen Anne, were dead. Leibniz played a role in the initiatives and negotiations leading up to that Act, but not always an effective one. For example, something he published anonymously in England, thinking to promote the Brunswick cause, was formally censured by the
British Parliament The Parliament of the United Kingdom of Great Britain and Northern Ireland is the supreme legislative body of the United Kingdom, and may also legislate for the Crown Dependencies and the British Overseas Territories. It meets at the Palace of ...
. The Brunswicks tolerated the enormous effort Leibniz devoted to intellectual pursuits unrelated to his duties as a courtier, pursuits such as perfecting calculus, writing about other mathematics, logic, physics, and philosophy, and keeping up a vast correspondence. He began working on calculus in 1674; the earliest evidence of its use in his surviving notebooks is 1675. By 1677 he had a coherent system in hand, but did not publish it until 1684. Leibniz's most important mathematical papers were published between 1682 and 1692, usually in a journal which he and
Otto Mencke Otto Mencke (; ; 22 March 1644 – 18 January 1707) was a 17th-century German philosopher and scientist. Work Mencke obtained his doctorate at the University of Leipzig in August 1666 with a thesis entitled: ''Ex Theologia naturali – De ...
founded in 1682, the ''
Acta Eruditorum (from Latin: ''Acts of the Erudite'') was the first scientific journal of the German-speaking lands of Europe, published from 1682 to 1782. History ''Acta Eruditorum'' was founded in 1682 in Leipzig by Otto Mencke, who became its first edit ...
''. That journal played a key role in advancing his mathematical and scientific reputation, which in turn enhanced his eminence in diplomacy, history, theology, and philosophy. The Elector Ernest Augustus commissioned Leibniz to write a history of the House of Brunswick, going back to the time of
Charlemagne Charlemagne ( ; 2 April 748 – 28 January 814) was List of Frankish kings, King of the Franks from 768, List of kings of the Lombards, King of the Lombards from 774, and Holy Roman Emperor, Emperor of what is now known as the Carolingian ...
or earlier, hoping that the resulting book would advance his dynastic ambitions. From 1687 to 1690, Leibniz traveled extensively in Germany, Austria, and Italy, seeking and finding archival materials bearing on this project. Decades went by but no history appeared; the next Elector became quite annoyed at Leibniz's apparent dilatoriness. Leibniz never finished the project, in part because of his huge output on many other fronts, but also because he insisted on writing a meticulously researched and erudite book based on archival sources, when his patrons would have been quite happy with a short popular book, one perhaps little more than a
genealogy Genealogy () is the study of families, family history, and the tracing of their lineages. Genealogists use oral interviews, historical records, genetic analysis, and other records to obtain information about a family and to demonstrate kin ...
with commentary, to be completed in three years or less. They never knew that he had in fact carried out a fair part of his assigned task: when the material Leibniz had written and collected for his history of the House of Brunswick was finally published in the 19th century, it filled three volumes. Leibniz was appointed Librarian of the
Herzog August Library The Herzog August Library ( — "HAB"), in Wolfenbüttel, Lower Saxony, known also as ''Bibliotheca Augusta'', is a library of international importance for its collection from the Middle Ages and early modern Europe. The library is overseen ...
in
Wolfenbüttel Wolfenbüttel (; ) is a town in Lower Saxony, Germany, the administrative capital of Wolfenbüttel District Wolfenbüttel (; ) is a town in Lower Saxony, Germany, the administrative capital of Wolfenbüttel (district), Wolfenbüttel Distri ...
,
Lower Saxony Lower Saxony is a States of Germany, German state (') in Northern Germany, northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ' of the Germany, Federal Re ...
, in 1691. In 1708,
John Keill John Keill FRS (1 December 1671 – 31 August 1721) was a Scottish mathematician, natural philosopher, and cryptographer who was an important defender of Isaac Newton. Biography Keill was born in Edinburgh, Scotland on 1 December 1671. His fa ...
, writing in the journal of the Royal Society and with Newton's presumed blessing, accused Leibniz of having plagiarised Newton's calculus. Thus began the calculus priority dispute which darkened the remainder of Leibniz's life. A formal investigation by the Royal Society (in which Newton was an unacknowledged participant), undertaken in response to Leibniz's demand for a retraction, upheld Keill's charge. Historians of mathematics writing since 1900 or so have tended to acquit Leibniz, pointing to important differences between Leibniz's and Newton's versions of calculus. In 1712, Leibniz began a two-year residence in Vienna, where he was appointed Imperial Court Councillor to the
Habsburg The House of Habsburg (; ), also known as the House of Austria, was one of the most powerful dynasties in the history of Europe and Western civilization. They were best known for their inbreeding and for ruling vast realms throughout Europe d ...
s. On the death of Queen Anne in 1714, Elector George Louis became King
George I of Great Britain George I (George Louis; ; 28 May 1660 – 11 June 1727) was King of Great Britain and King of Ireland, Ireland from 1 August 1714 and ruler of the Electorate of Hanover within the Holy Roman Empire from 23 January 1698 until his death in 1727. ...
, under the terms of the 1701 Act of Settlement. Even though Leibniz had done much to bring about this happy event, it was not to be his hour of glory. Despite the intercession of the Princess of Wales, Caroline of Ansbach, George I forbade Leibniz to join him in London until he completed at least one volume of the history of the Brunswick family his father had commissioned nearly 30 years earlier. Moreover, for George I to include Leibniz in his London court would have been deemed insulting to Newton, who was seen as having won the calculus priority dispute and whose standing in British official circles could not have been higher. Finally, his dear friend and defender, the Dowager Electress Sophia, died in 1714. In 1716, while traveling in northern Europe, the Russian
Tsar Tsar (; also spelled ''czar'', ''tzar'', or ''csar''; ; ; sr-Cyrl-Latn, цар, car) is a title historically used by Slavic monarchs. The term is derived from the Latin word '' caesar'', which was intended to mean ''emperor'' in the Euro ...
Peter the Great Peter I (, ; – ), better known as Peter the Great, was the Sovereign, Tsar and Grand Prince of all Russia, Tsar of all Russia from 1682 and the first Emperor of Russia, Emperor of all Russia from 1721 until his death in 1725. He reigned j ...
stopped in
Bad Pyrmont Bad Pyrmont (, also: ; West Low German: ) is a town in the district of Hamelin-Pyrmont, in Lower Saxony, Germany, with a population close to 19,000. It is located on the river Emmer (Weser), Emmer, about west of the Weser. Bad Pyrmont is a popul ...
and met Leibniz, who took interest in Russian matters since 1708 and was appointed advisor in 1711.


Death

Leibniz died in
Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...
in 1716. At the time, he was so out of favor that neither George I (who happened to be near Hanover at that time) nor any fellow courtier other than his personal secretary attended the funeral. Even though Leibniz was a life member of the Royal Society and the Berlin Academy of Sciences, neither organization saw fit to honor his death. His grave went unmarked for more than 50 years. He was, however, eulogized by Fontenelle, before the
French Academy of Sciences The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
in Paris, which had admitted him as a foreign member in 1700. The eulogy was composed at the behest of the Duchess of Orleans, a niece of the Electress Sophia.


Personal life

Leibniz never married. He proposed to an unknown woman at age 50, but changed his mind when she took too long to decide. He complained on occasion about money, but the fair sum he left to his sole heir, his sister's stepson, proved that the Brunswicks had paid him fairly well. In his diplomatic endeavors, he at times verged on the unscrupulous, as was often the case with professional diplomats of his day. On several occasions, Leibniz backdated and altered personal manuscripts, actions which put him in a bad light during the calculus controversy. He was charming, well-mannered, and not without humor and imagination. He had many friends and admirers all over Europe. He was identified as a
Protestant Protestantism is a branch of Christianity that emphasizes Justification (theology), justification of sinners Sola fide, through faith alone, the teaching that Salvation in Christianity, salvation comes by unmerited Grace in Christianity, divin ...
and a philosophical theist. Leibniz remained committed to
Trinitarian Christianity The Trinity (, from 'threefold') is the Christian doctrine concerning the nature of God, which defines one God existing in three, , consubstantial divine persons: God the Father, God the Son (Jesus Christ) and God the Holy Spirit, three ...
throughout his life.


Philosophy

Leibniz's philosophical thinking appears fragmented because his philosophical writings consist mainly of a multitude of short pieces: journal articles, manuscripts published long after his death, and letters to correspondents. He wrote two book-length philosophical treatises, of which only the ''Théodicée'' of 1710 was published in his lifetime. Leibniz dated his beginning as a philosopher to his ''
Discourse on Metaphysics The ''Discourse on Metaphysics'' (, 1686) is a short treatise by Gottfried Wilhelm Leibniz in which he develops a philosophy concerning physical substance, motion and resistance of bodies, and God's role within the universe. It is one of the few ...
'', which he composed in 1686 as a commentary on a running dispute between
Nicolas Malebranche Nicolas Malebranche ( ; ; 6 August 1638 – 13 October 1715) was a French Oratorian Catholic priest and rationalist philosopher. In his works, he sought to synthesise the thought of St. Augustine and Descartes, in order to demonstrate the ...
and
Antoine Arnauld Antoine Arnauld (; 6 February 16128 August 1694) was a French Catholic theologian, priest, philosopher and mathematician. He was one of the leading intellectuals of the Jansenist group of Port-Royal and had a very thorough knowledge of patr ...
. This led to an extensive correspondence with Arnauld; it and the ''Discourse'' were not published until the 19th century. In 1695, Leibniz made his public entrée into European philosophy with a journal article titled "New System of the Nature and Communication of Substances". Between 1695 and 1705, he composed his ''
New Essays on Human Understanding ''New Essays on Human Understanding'' () is a chapter-by-chapter rebuttal by Gottfried Leibniz of John Locke's major work '' An Essay Concerning Human Understanding'' (1689). It is one of only two full-length works by Leibniz (the other being the ...
'', a lengthy commentary on
John Locke John Locke (; 29 August 1632 (Old Style and New Style dates, O.S.) – 28 October 1704 (Old Style and New Style dates, O.S.)) was an English philosopher and physician, widely regarded as one of the most influential of the Enlightenment thi ...
's 1690 ''
An Essay Concerning Human Understanding ''An Essay Concerning Human Understanding'' is a work by John Locke concerning the foundation of human knowledge and understanding. It first appeared in 1689 (although dated 1690) with the printed title ''An Essay Concerning Humane Understand ...
'', but upon learning of Locke's 1704 death, lost the desire to publish it, so that the ''New Essays'' were not published until 1765. The ''
Monadologie The ''Monadology'' (, 1714) is one of Gottfried Leibniz's best known works of his later philosophy. It is a short text which presents, in some 90 paragraphs, a metaphysics of simple substance theory, substances, or ''monad (philosophy), monads'' ...
'', composed in 1714 and published posthumously, consists of 90 aphorisms. Leibniz also wrote a short paper, "Primae veritates" ("First Truths"), first published by
Louis Couturat Louis Couturat (; 17 January 1868 – 3 August 1914) was a French logician, mathematician, philosopher, and linguist. Couturat was a pioneer of the constructed language Ido. Life and education Born in Paris. In 1887 he entered École Normale S ...
in 1903 (pp. 518–523) summarizing his views on
metaphysics Metaphysics is the branch of philosophy that examines the basic structure of reality. It is traditionally seen as the study of mind-independent features of the world, but some theorists view it as an inquiry into the conceptual framework of ...
. The paper is undated; that he wrote it while in Vienna in 1689 was determined only in 1999, when the ongoing critical edition finally published Leibniz's philosophical writings for the period 1677–1690. Couturat's reading of this paper influenced much 20th-century thinking about Leibniz, especially among
analytic philosophers Analytic philosophy is a broad movement within Western philosophy, especially anglophone philosophy, focused on analysis as a philosophical method; clarity of prose; rigor in arguments; and making use of formal logic, mathematics, and to a less ...
. After a meticulous study (informed by the 1999 additions to the critical edition) of all of Leibniz's philosophical writings up to 1688, Mercer (2001) disagreed with Couturat's reading. Leibniz met
Baruch Spinoza Baruch (de) Spinoza (24 November 163221 February 1677), also known under his Latinized pen name Benedictus de Spinoza, was a philosopher of Portuguese-Jewish origin, who was born in the Dutch Republic. A forerunner of the Age of Enlightenmen ...
in 1676, read some of his unpublished writings, and had since been influenced by some of Spinoza's ideas. While Leibniz befriended him and admired Spinoza's powerful intellect, he was also dismayed by Spinoza's conclusions, especially when these were inconsistent with Christian orthodoxy. Unlike Descartes and Spinoza, Leibniz had a university education in philosophy. He was influenced by his
Leipzig Leipzig (, ; ; Upper Saxon: ; ) is the most populous city in the States of Germany, German state of Saxony. The city has a population of 628,718 inhabitants as of 2023. It is the List of cities in Germany by population, eighth-largest city in Ge ...
professor
Jakob Thomasius Jakob Thomasius (; ; 27 August 1622 – 9 September 1684) was a German academic philosopher and jurist. He is now regarded as an important founding figure in the scholarly study of the history of philosophy. His views were eclectic, and were tak ...
, who also supervised his BA thesis in philosophy.Arthur 2014, p. 13. Leibniz also read
Francisco Suárez Francisco Suárez (; 5 January 1548 – 25 September 1617) was a Spanish Jesuit priest, philosopher and theologian, one of the leading figures of the School of Salamanca movement. His work is considered a turning point in the history of second ...
, a Spanish
Jesuit The Society of Jesus (; abbreviation: S.J. or SJ), also known as the Jesuit Order or the Jesuits ( ; ), is a religious order (Catholic), religious order of clerics regular of pontifical right for men in the Catholic Church headquartered in Rom ...
respected even in
Lutheran Lutheranism is a major branch of Protestantism that emerged under the work of Martin Luther, the 16th-century German friar and Protestant Reformers, reformer whose efforts to reform the theology and practices of the Catholic Church launched ...
universities. Leibniz was deeply interested in the new methods and conclusions of Descartes, Huygens, Newton, and
Boyle Boyle may refer to: Places United States * Boyle, Kansas, an unincorporated community * Boyle, Mississippi, a town *Boyle County, Kentucky *Boyle Heights, Los Angeles, a neighborhood Elsewhere * Boyle (crater), a lunar crater * 11967 Boyle, ...
, but the established philosophical ideas in which he was educated influenced his view of their work.


Principles

Leibniz variously invoked one or another of seven fundamental philosophical Principles: *
Identity Identity may refer to: * Identity document * Identity (philosophy) * Identity (social science) * Identity (mathematics) Arts and entertainment Film and television * ''Identity'' (1987 film), an Iranian film * ''Identity'' (2003 film), an ...
/
contradiction In traditional logic, a contradiction involves a proposition conflicting either with itself or established fact. It is often used as a tool to detect disingenuous beliefs and bias. Illustrating a general tendency in applied logic, Aristotle's ...
. If a proposition is true, then its negation is false and vice versa. *
Identity of indiscernibles The identity of indiscernibles is an ontological principle that states that there cannot be separate objects or entities that have all their properties in common. That is, entities ''x'' and ''y'' are identical if every predicate possessed by ...
. Two distinct things cannot have all their properties in common. If every predicate possessed by ''x'' is also possessed by ''y'' and vice versa, then entities ''x'' and ''y'' are identical; to suppose two things indiscernible is to suppose the same thing under two names. The "identity of indiscernibles" is frequently invoked in modern logic and philosophy. It has attracted the most controversy and criticism, especially from corpuscular philosophy and quantum mechanics. The converse of this is often called ''Leibniz's law'', or the ''indiscernibility of identicals'', which is mostly uncontroversial. * Sufficient reason. "There must be a sufficient reason for anything to exist, for any event to occur, for any truth to obtain." * Pre-established harmony. " e appropriate nature of each substance brings it about that what happens to one corresponds to what happens to all the others, without, however, their acting upon one another directly." (''Discourse on Metaphysics'', XIV) A dropped glass shatters because it "knows" it has hit the ground, and not because the impact with the ground "compels" the glass to split. *
Law of continuity Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior, with its precise definition a matter of longstanding debate. It has been variously described as a science and as the ar ...
. ''
Natura non facit saltus ''Natura non facit saltus'' Alexander Baumgarten, ''Metaphysics: A Critical Translation with Kant's Elucidations'', Translated and Edited by Courtney D. Fugate and John Hymers, Bloomsbury, 2013, "Preface of the Third Edition (1750)"p. 79 n. d " a ...
''Gottfried Leibniz, ''New Essays'', IV, 16: "''la nature ne fait jamais des sauts''". ''Natura non-facit saltus'' is the Latin translation of the phrase (originally put forward by
Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
' ''
Philosophia Botanica ''Philosophia Botanica'' ("Botanical Philosophy", ed. 1, Stockholm & Amsterdam, 1751.) was published by the Swedish naturalist and physician Carl Linnaeus (1707–1778) who greatly influenced the development of botanical Taxonomy (biology), taxono ...
'', 1st ed., 1751, Chapter III, § 77, p. 27. See also See also
Alexander Baumgarten Alexander Gottlieb Baumgarten (; ; 17 July 1714 – 27 MayJan LekschasBaumgarten Family'' 1762) was a German philosopher. He was a brother to theologian Siegmund Jakob Baumgarten (1706–1757). Biography Baumgarten was born in Berlin as the ...
, ''Metaphysics: A Critical Translation with Kant's Elucidations'', Translated and Edited by Courtney D. Fugate and John Hymers, Bloomsbury, 2013, "Preface of the Third Edition (1750)"
p. 79 n.d.
" aumgartenmust also have in mind Leibniz's "''natura non-facit saltus'' ature does not make leaps ( NE IV, 16)."). A variant translation is "''natura non-saltum facit''" (literally, "Nature does not make a jump")
Extract of page 289
)
(literally, "Nature does not make jumps"). *
Optimism Optimism is the Attitude (psychology), attitude or mindset of expecting events to lead to particularly positive, favorable, desirable, and hopeful outcomes. A common idiom used to illustrate optimism versus pessimism is Is the glass half empty ...
. "God assuredly always chooses the best." * Plenitude. Leibniz believed that the best of all possible worlds would actualize every genuine possibility, and argued in ''Théodicée'' that this best of all possible worlds will contain all possibilities, with our finite experience of eternity giving no reason to dispute nature's perfection. Leibniz would on occasion give a rational defense of a specific principle, but more often took them for granted.


Monads

Leibniz's best known contribution to
metaphysics Metaphysics is the branch of philosophy that examines the basic structure of reality. It is traditionally seen as the study of mind-independent features of the world, but some theorists view it as an inquiry into the conceptual framework of ...
is his theory of monads, as exposited in ''
Monadologie The ''Monadology'' (, 1714) is one of Gottfried Leibniz's best known works of his later philosophy. It is a short text which presents, in some 90 paragraphs, a metaphysics of simple substance theory, substances, or ''monad (philosophy), monads'' ...
''. He proposes his theory that the universe is made of an infinite number of simple substances known as monads. Monads can also be compared to the corpuscles of the
mechanical philosophy Mechanism is the belief that natural wholes (principally living things) are similar to complicated machines or artifacts, composed of parts lacking any intrinsic relationship to each other. The doctrine of mechanism in philosophy comes in two diff ...
of René Descartes and others. These simple substances or monads are the "ultimate units of existence in nature". Monads have no parts but still exist by the qualities that they have. These qualities are continuously changing over time, and each monad is unique. They are also not affected by time and are subject to only creation and annihilation. Monads are centers of
force In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitu ...
; substance is force, while
space Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless ...
,
matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic pa ...
, and
motion In physics, motion is when an object changes its position with respect to a reference point in a given time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and frame of reference to an o ...
are merely phenomenal. He argued, against Newton, that
space Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless ...
,
time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...
, and motion are completely relative: "As for my own opinion, I have said more than once, that I hold space to be something merely relative, as time is, that I hold it to be an order of coexistences, as time is an order of successions."See H. G. Alexander, ed., ''The Leibniz-Clarke Correspondence'', Manchester: Manchester University Press, pp. 25–26. Einstein, who called himself a "Leibnizian", wrote in the introduction to
Max Jammer Max Jammer (; born Moshe Jammer, ; 13 April 1915 – 18 December 2010), was an Israeli physicist and philosophy of physics, philosopher of physics. He was born in Berlin, Germany. He was Rector and Acting President at Bar-Ilan University from 19 ...
's book ''Concepts of Space'' that Leibnizianism was superior to Newtonianism, and his ideas would have dominated over Newton's had it not been for the poor technological tools of the time; Joseph Agassi argues that Leibniz paved the way for Einstein's
theory of relativity The theory of relativity usually encompasses two interrelated physics theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical ph ...
. Leibniz's proof of God can be summarized in the ''
Théodicée (from French: ''Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil''), more simply known as , is a book of philosophy by the German polymath Gottfried Leibniz. The book, published in 1710, introduced the te ...
''. Reason is governed by the
principle of contradiction In logic, the law of noncontradiction (LNC; also known as the law of contradiction, principle of non-contradiction (PNC), or the principle of contradiction) states that for any given proposition, the proposition and its negation cannot both be s ...
and the
principle of sufficient reason The principle of sufficient reason states that everything must have a Reason (argument), reason or a cause. The principle was articulated and made prominent by Gottfried Wilhelm Leibniz, with many antecedents, and was further used and developed by ...
. Using the principle of reasoning, Leibniz concluded that the first reason of all things is God. All that we see and experience is subject to change, and the fact that this world is contingent can be explained by the possibility of the world being arranged differently in space and time. The contingent world must have some necessary reason for its existence. Leibniz uses a geometry book as an example to explain his reasoning. If this book was copied from an infinite chain of copies, there must be some reason for the content of the book. Leibniz concluded that there must be the "''monas monadum''" or God. The
ontological Ontology is the philosophical study of being. It is traditionally understood as the subdiscipline of metaphysics focused on the most general features of reality. As one of the most fundamental concepts, being encompasses all of reality and every ...
essence of a monad is its irreducible simplicity. Unlike atoms, monads possess no material or spatial character. They also differ from atoms by their complete mutual independence, so that interactions among monads are only apparent. Instead, by virtue of the principle of pre-established harmony, each monad follows a pre-programmed set of "instructions" peculiar to itself, so that a monad "knows" what to do at each moment. By virtue of these intrinsic instructions, each monad is like a little mirror of the universe. Monads need not be "small"; e.g., each human being constitutes a monad, in which case
free will Free will is generally understood as the capacity or ability of people to (a) choice, choose between different possible courses of Action (philosophy), action, (b) exercise control over their actions in a way that is necessary for moral respon ...
is problematic. Monads are purported to have gotten rid of the problematic: * interaction between
mind The mind is that which thinks, feels, perceives, imagines, remembers, and wills. It covers the totality of mental phenomena, including both conscious processes, through which an individual is aware of external and internal circumstances ...
and matter arising in the system of Descartes; * lack of
individuation The principle of individuation, or ', describes the manner in which a thing is identified as distinct from other things. The concept appears in numerous fields and is encountered in works of Leibniz, Carl Jung, Gunther Anders, Gilbert Simondo ...
inherent to the system of
Spinoza Baruch (de) Spinoza (24 November 163221 February 1677), also known under his Latinized pen name Benedictus de Spinoza, was a philosopher of Portuguese-Jewish origin, who was born in the Dutch Republic. A forerunner of the Age of Enlightenmen ...
, which represents individual creatures as merely accidental.


Theodicy and optimism

The ''
Theodicy In the philosophy of religion, a theodicy (; meaning 'vindication of God', from Ancient Greek θεός ''theos'', "god" and δίκη ''dikē'', "justice") is an argument that attempts to resolve the problem of evil that arises when all powe ...
'' tries to justify the apparent imperfections of the world by claiming that it is optimal among all possible worlds. It must be the best possible and most balanced world, because it was created by an all-powerful and all-knowing God, who would not choose to create an imperfect world if a better world could be known to him or possible to exist. In effect, apparent flaws that can be identified in this world must exist in every possible world, because otherwise God would have chosen to create the world that excluded those flaws. Leibniz asserted that the truths of theology (religion) and philosophy cannot contradict each other, since reason and faith are both "gifts of God" so that their conflict would imply God contending against himself. The ''Theodicy'' is Leibniz's attempt to reconcile his personal philosophical system with his interpretation of the tenets of Christianity. This project was motivated in part by Leibniz's belief, shared by many philosophers and theologians during the
Enlightenment Enlightenment or enlighten may refer to: Age of Enlightenment * Age of Enlightenment, period in Western intellectual history from the late 17th to late 18th century, centered in France but also encompassing (alphabetically by country or culture): ...
, in the rational and enlightened nature of the Christian religion. It was also shaped by Leibniz's belief in the perfectibility of human nature (if humanity relied on correct philosophy and religion as a guide), and by his belief that metaphysical necessity must have a rational or logical foundation, even if this metaphysical causality seemed inexplicable in terms of physical necessity (the natural laws identified by science). In the view of Leibniz, because reason and faith must be entirely reconciled, any tenet of faith which could not be defended by reason must be rejected. Leibniz then approached one of the central criticisms of Christian theism: if God is all good, all wise, and all powerful, then how did evil come into the world? The answer (according to Leibniz) is that, while God is indeed unlimited in wisdom and power, his human creations, as creations, are limited both in their wisdom and in their will (power to act). This predisposes humans to false beliefs, wrong decisions, and ineffective actions in the exercise of their
free will Free will is generally understood as the capacity or ability of people to (a) choice, choose between different possible courses of Action (philosophy), action, (b) exercise control over their actions in a way that is necessary for moral respon ...
. God does not arbitrarily inflict pain and suffering on humans; rather he permits both ''moral evil'' (sin) and ''physical evil'' (pain and suffering) as the necessary consequences of ''metaphysical evil'' (imperfection), as a means by which humans can identify and correct their erroneous decisions, and as a contrast to true good. Further, although human actions flow from prior causes that ultimately arise in God and therefore are known to God as metaphysical certainties, an individual's free will is exercised within natural laws, where choices are merely contingently necessary and to be decided in the event by a "wonderful spontaneity" that provides individuals with an escape from rigorous predestination.


''Discourse on Metaphysics''

For Leibniz, "God is an absolutely perfect being". He describes this perfection later in section VI as the simplest form of something with the most substantial outcome (VI). Along these lines, he declares that every type of perfection "pertains to him (God) in the highest degree" (I). Even though his types of perfections are not specifically drawn out, Leibniz highlights the one thing that, to him, does certify imperfections and proves that God is perfect: "that one acts imperfectly if he acts with less perfection than he is capable of", and since God is a perfect being, he cannot act imperfectly (III). Because God cannot act imperfectly, the decisions he makes pertaining to the world must be perfect. Leibniz also comforts readers, stating that because he has done everything to the most perfect degree; those who love him cannot be injured. However, to love God is a subject of difficulty as Leibniz believes that we are "not disposed to wish for that which God desires" because we have the ability to alter our disposition (IV). In accordance with this, many act as rebels, but Leibniz says that the only way we can truly love God is by being content "with all that comes to us according to his will" (IV). Because God is "an absolutely perfect being" (I), Leibniz argues that God would be acting imperfectly if he acted with any less perfection than what he is able of (III). His syllogism then ends with the statement that God has made the world perfectly in all ways. This also affects how we should view God and his will. Leibniz states that, in lieu of God's will, we have to understand that God "is the best of all masters" and he will know when his good succeeds, so we, therefore, must act in conformity to his good will—or as much of it as we understand (IV). In our view of God, Leibniz declares that we cannot admire the work solely because of the maker, lest we mar the glory and love God in doing so. Instead, we must admire the maker for the work he has done (II). Effectively, Leibniz states that if we say the earth is good because of the will of God, and not good according to some standards of goodness, then how can we praise God for what he has done if contrary actions are also praiseworthy by this definition (II). Leibniz then asserts that different principles and geometry cannot simply be from the will of God, but must follow from his understanding. Leibniz wrote: " Why is there something rather than nothing? The sufficient reason ... is found in a substance which ... is a necessary being bearing the reason for its existence within itself."
Martin Heidegger Martin Heidegger (; 26 September 1889 – 26 May 1976) was a German philosopher known for contributions to Phenomenology (philosophy), phenomenology, hermeneutics, and existentialism. His work covers a range of topics including metaphysics, art ...
called this question "the fundamental question of metaphysics".


Symbolic thought and rational resolution of disputes

Leibniz believed that much of human reasoning could be reduced to calculations of a sort, and that such calculations could resolve many differences of opinion: Leibniz's
calculus ratiocinator The ''calculus ratiocinator'' is a theoretical universal logical calculation framework, a concept described in the writings of Gottfried Leibniz, usually paired with his more frequently mentioned ''characteristica universalis'', a universal conc ...
, which resembles
symbolic logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o ...
, can be viewed as a way of making such calculations feasible. Leibniz wrote memoranda that can now be read as groping attempts to get symbolic logic—and thus his ''calculus''—off the ground. These writings remained unpublished until the appearance of a selection edited by Carl Immanuel Gerhardt (1859).
Louis Couturat Louis Couturat (; 17 January 1868 – 3 August 1914) was a French logician, mathematician, philosopher, and linguist. Couturat was a pioneer of the constructed language Ido. Life and education Born in Paris. In 1887 he entered École Normale S ...
published a selection in 1901; by this time the main developments of modern logic had been created by
Charles Sanders Peirce Charles Sanders Peirce ( ; September 10, 1839 – April 19, 1914) was an American scientist, mathematician, logician, and philosopher who is sometimes known as "the father of pragmatism". According to philosopher Paul Weiss (philosopher), Paul ...
and by
Gottlob Frege Friedrich Ludwig Gottlob Frege (; ; 8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician. He was a mathematics professor at the University of Jena, and is understood by many to be the father of analytic philos ...
. Leibniz thought
symbol A symbol is a mark, Sign (semiotics), sign, or word that indicates, signifies, or is understood as representing an idea, physical object, object, or wikt:relationship, relationship. Symbols allow people to go beyond what is known or seen by cr ...
s were important for human understanding. He attached so much importance to the development of good notations that he attributed all his discoveries in mathematics to this. His notation for
calculus Calculus is the mathematics, mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithmetic operations. Originally called infinitesimal calculus or "the ...
is an example of his skill in this regard. Leibniz's passion for symbols and notation, as well as his belief that these are essential to a well-running logic and mathematics, made him a precursor of
semiotics Semiotics ( ) is the systematic study of sign processes and the communication of meaning. In semiotics, a sign is defined as anything that communicates intentional and unintentional meaning or feelings to the sign's interpreter. Semiosis is a ...
. But Leibniz took his speculations much further. Defining a character as any written sign, he then defined a "real" character as one that represents an idea directly and not simply as the word embodying the idea. Some real characters, such as the notation of logic, serve only to facilitate reasoning. Many characters well known in his day, including
Egyptian hieroglyphics Ancient Egyptian hieroglyphs ( ) were the formal writing system used in Ancient Egypt for writing the Egyptian language. Hieroglyphs combined ideographic, logographic, syllabic and alphabetic elements, with more than 1,000 distinct characters.I ...
,
Chinese character Chinese characters are logographs used to write the Chinese languages and others from regions historically influenced by Chinese culture. Of the four independently invented writing systems accepted by scholars, they represent the only on ...
s, and the symbols of
astronomy Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest includ ...
and
chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
, he deemed not real. Instead, he proposed the creation of a ''
characteristica universalis The Latin term ''characteristica universalis'', commonly interpreted as ''universal characteristic'', or ''universal character'' in English, is a universal and formal language imagined by Gottfried Leibniz able to express mathematical, scienti ...
'' or "universal characteristic", built on an
alphabet of human thought The alphabet of human thought () is a concept originally proposed by Gottfried Wilhelm Leibniz that provides a universal way to represent and analyze ideas and relationships by breaking down their component pieces. All ideas are compounded from a ...
in which each fundamental concept would be represented by a unique "real" character: Complex thoughts would be represented by combining characters for simpler thoughts. Leibniz saw that the uniqueness of
prime factorization In mathematics, integer factorization is the decomposition of a positive integer into a product of integers. Every positive integer greater than 1 is either the product of two or more integer factors greater than 1, in which case it is a comp ...
suggests a central role for
prime numbers A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways ...
in the universal characteristic, a striking anticipation of
Gödel numbering In mathematical logic, a Gödel numbering is a function that assigns to each symbol and well-formed formula of some formal language a unique natural number, called its Gödel number. Kurt Gödel developed the concept for the proof of his incom ...
. Granted, there is no intuitive or
mnemonic A mnemonic device ( ), memory trick or memory device is any learning technique that aids information retention or retrieval in the human memory, often by associating the information with something that is easier to remember. It makes use of e ...
way to number any set of elementary concepts using the prime numbers. Because Leibniz was a mathematical novice when he first wrote about the ''characteristic'', at first he did not conceive it as an
algebra Algebra is a branch of mathematics that deals with abstract systems, known as algebraic structures, and the manipulation of expressions within those systems. It is a generalization of arithmetic that introduces variables and algebraic ope ...
but rather as a
universal language Universal language may refer to a hypothetical or historical language spoken and understood by all or most of the world's people. In some contexts, it refers to a means of communication said to be understood by all humans. It may be the idea o ...
or script. Only in 1676 did he conceive of a kind of "algebra of thought", modeled on and including conventional algebra and its notation. The resulting ''characteristic'' included a logical calculus, some combinatorics, algebra, his ''analysis situs'' (geometry of situation), a universal concept language, and more. What Leibniz actually intended by his ''characteristica universalis'' and calculus ratiocinator, and the extent to which modern formal logic does justice to calculus, may never be established. Leibniz's idea of reasoning through a universal language of symbols and calculations remarkably foreshadows great 20th-century developments in formal systems, such as
Turing completeness In computability theory, a system of data-manipulation rules (such as a model of computation, a computer's instruction set, a programming language, or a cellular automaton) is said to be Turing-complete or computationally universal if it can b ...
, where computation was used to define equivalent universal languages (see
Turing degree In computer science and mathematical logic the Turing degree (named after Alan Turing) or degree of unsolvability of a set of natural numbers measures the level of algorithmic unsolvability of the set. Overview The concept of Turing degree is fund ...
).


Formal logic

Leibniz has been noted as one of the most important logicians between the times of Aristotle and
Gottlob Frege Friedrich Ludwig Gottlob Frege (; ; 8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician. He was a mathematics professor at the University of Jena, and is understood by many to be the father of analytic philos ...
. Leibniz enunciated the principal properties of what we now call conjunction,
disjunction In logic, disjunction (also known as logical disjunction, logical or, logical addition, or inclusive disjunction) is a logical connective typically notated as \lor and read aloud as "or". For instance, the English language sentence "it is ...
,
negation In logic, negation, also called the logical not or logical complement, is an operation (mathematics), operation that takes a Proposition (mathematics), proposition P to another proposition "not P", written \neg P, \mathord P, P^\prime or \over ...
,
identity Identity may refer to: * Identity document * Identity (philosophy) * Identity (social science) * Identity (mathematics) Arts and entertainment Film and television * ''Identity'' (1987 film), an Iranian film * ''Identity'' (2003 film), an ...
, set
inclusion Inclusion or Include may refer to: Sociology * Social inclusion, action taken to support people of different backgrounds sharing life together. ** Inclusion (disability rights), promotion of people with disabilities sharing various aspects of lif ...
, and the
empty set In mathematics, the empty set or void set is the unique Set (mathematics), set having no Element (mathematics), elements; its size or cardinality (count of elements in a set) is 0, zero. Some axiomatic set theories ensure that the empty set exi ...
. The principles of Leibniz's logic and, arguably, of his whole philosophy, reduce to two: # All our ideas are compounded from a very small number of simple ideas, which form the
alphabet of human thought The alphabet of human thought () is a concept originally proposed by Gottfried Wilhelm Leibniz that provides a universal way to represent and analyze ideas and relationships by breaking down their component pieces. All ideas are compounded from a ...
. # Complex ideas proceed from these simple ideas by a uniform and symmetrical combination, analogous to arithmetical multiplication. The formal logic that emerged early in the 20th century also requires, at minimum, unary negation and quantified
variables Variable may refer to: Computer science * Variable (computer science), a symbolic name associated with a value and whose associated value may be changed Mathematics * Variable (mathematics), a symbol that represents a quantity in a mathemat ...
ranging over some
universe of discourse In the formal sciences, the domain of discourse or universe of discourse (borrowing from the mathematical concept of ''universe'') is the set of entities over which certain variables of interest in some formal treatment may range. It is also ...
. Leibniz published nothing on formal logic in his lifetime; most of what he wrote on the subject consists of working drafts. In his ''
History of Western Philosophy Western philosophy refers to the Philosophy, philosophical thought, traditions and works of the Western world. Historically, the term refers to the philosophical thinking of Western culture, beginning with the ancient Greek philosophy of the Pre ...
'',
Bertrand Russell Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British philosopher, logician, mathematician, and public intellectual. He had influence on mathematics, logic, set theory, and various areas of analytic ...
went so far as to claim that Leibniz had developed logic in his unpublished writings to a level which was reached only 200 years later. Russell's principal work on Leibniz found that many of Leibniz's most startling philosophical ideas and claims (e.g., that each of the fundamental monads mirrors the whole universe) follow logically from Leibniz's conscious choice to reject ''relations'' between things as unreal. He regarded such relations as (real) ''qualities'' of things (Leibniz admitted unary predicates only): For him, "Mary is the mother of John" describes separate qualities of Mary and of John. This view contrasts with the relational logic of De Morgan, Peirce,
Schröder Schröder (Schroeder) is a German language, German surname often associated with the Schröder family. Notable people with the surname include: * Arthur Schröder (1892–1986), German actor * Atze Schröder, stage name of German comedian Hubertu ...
and Russell himself, now standard in
predicate logic First-order logic, also called predicate logic, predicate calculus, or quantificational logic, is a collection of formal systems used in mathematics, philosophy, linguistics, and computer science. First-order logic uses quantified variables ove ...
. Notably, Leibniz also declared space and time to be inherently relational. Leibniz's 1690 discovery of his algebra of concepts (deductively equivalent to the
Boolean algebra In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variable (mathematics), variables are the truth values ''true'' and ''false'', usually denot ...
) and the associated metaphysics, are of interest in present-day
computational metaphysics Abstract object theory (AOT) is a branch of metaphysics regarding abstract objects. Originally devised by metaphysician Edward Zalta in 1981, the theory was an expansion of mathematical Platonism. Overview ''Abstract Objects: An Introduction ...
.


Mathematics

Although the mathematical notion of
function Function or functionality may refer to: Computing * Function key, a type of key on computer keyboards * Function model, a structured representation of processes in a system * Function object or functor or functionoid, a concept of object-orie ...
was implicit in trigonometric and logarithmic tables, which existed in his day, Leibniz was the first, in 1692 and 1694, to employ it explicitly, to denote any of several geometric concepts derived from a curve, such as
abscissa In mathematics, the abscissa (; plural ''abscissae'' or ''abscissas'') and the ordinate are respectively the first and second coordinate of a point in a Cartesian coordinate system: : abscissa \equiv x-axis (horizontal) coordinate : ordinate \eq ...
,
ordinate In mathematics, the abscissa (; plural ''abscissae'' or ''abscissas'') and the ordinate are respectively the first and second coordinate of a point in a Cartesian coordinate system: : abscissa \equiv x-axis (horizontal) coordinate : ordinate \e ...
,
tangent In geometry, the tangent line (or simply tangent) to a plane curve at a given point is, intuitively, the straight line that "just touches" the curve at that point. Leibniz defined it as the line through a pair of infinitely close points o ...
, chord, and the
perpendicular In geometry, two geometric objects are perpendicular if they intersect at right angles, i.e. at an angle of 90 degrees or π/2 radians. The condition of perpendicularity may be represented graphically using the '' perpendicular symbol'', ...
(see
History of the function concept The mathematical concept of a function dates from the 17th century in connection with the development of calculus; for example, the slope dy/dx of a graph at a point was regarded as a function of the ''x''-coordinate of the point. Functions were ...
). In the 18th century, "function" lost these geometrical associations. Leibniz was also one of the pioneers in
actuarial science Actuarial science is the discipline that applies mathematics, mathematical and statistics, statistical methods to Risk assessment, assess risk in insurance, pension, finance, investment and other industries and professions. Actuary, Actuaries a ...
, calculating the purchase price of life annuities and the liquidation of a state's debt. Leibniz's research into formal logic, also relevant to mathematics, is discussed in the preceding section. The best overview of Leibniz's writings on calculus may be found in Bos (1974). Leibniz, who invented one of the earliest mechanical calculators, said of
calculation A calculation is a deliberate mathematical process that transforms a plurality of inputs into a singular or plurality of outputs, known also as a result or results. The term is used in a variety of senses, from the very definite arithmetical ...
: "For it is unworthy of excellent men to lose hours like slaves in the labor of calculation which could safely be relegated to anyone else if machines were used."


Linear systems

Leibniz arranged the coefficients of a system of
linear equation In mathematics, a linear equation is an equation that may be put in the form a_1x_1+\ldots+a_nx_n+b=0, where x_1,\ldots,x_n are the variables (or unknowns), and b,a_1,\ldots,a_n are the coefficients, which are often real numbers. The coeffici ...
s into an array, now called a
matrix Matrix (: matrices or matrixes) or MATRIX may refer to: Science and mathematics * Matrix (mathematics), a rectangular array of numbers, symbols or expressions * Matrix (logic), part of a formula in prenex normal form * Matrix (biology), the m ...
, in order to find a solution to the system if it existed. This method was later called
Gaussian elimination In mathematics, Gaussian elimination, also known as row reduction, is an algorithm for solving systems of linear equations. It consists of a sequence of row-wise operations performed on the corresponding matrix of coefficients. This method can a ...
. Leibniz laid down the foundations and theory of
determinants In mathematics, the determinant is a scalar-valued function of the entries of a square matrix. The determinant of a matrix is commonly denoted , , or . Its value characterizes some properties of the matrix and the linear map represented, on a ...
, although the Japanese mathematician
Seki Takakazu , Selin, Helaine. (1997). ''Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures,'' p. 890 also known as ,Selin, was a mathematician, samurai, and Kofu feudal officer of the early Edo period of Japan. Se ...
also discovered determinants independently of Leibniz. His works show calculating the determinants using cofactors. Calculating the determinant using cofactors is named the Leibniz formula. Finding the determinant of a matrix using this method proves impractical with large ''n'', requiring to calculate ''n!'' products and the number of n-permutations. He also solved systems of linear equations using determinants, which is now called
Cramer's rule In linear algebra, Cramer's rule is an explicit formula for the solution of a system of linear equations with as many equations as unknowns, valid whenever the system has a unique solution. It expresses the solution in terms of the determinants of ...
. This method for solving systems of linear equations based on determinants was found in 1684 by Leibniz (
Gabriel Cramer Gabriel Cramer (; 31 July 1704 – 4 January 1752) was a Genevan mathematician. Biography Cramer was born on 31 July 1704 in Geneva, Republic of Geneva to Jean-Isaac Cramer, a physician, and Anne Mallet. The progenitor of the Cramer family i ...
published his findings in 1750). Although Gaussian elimination requires O(n^3) arithmetic operations, linear algebra textbooks still teach cofactor expansion before
LU factorization In numerical analysis and linear algebra, lower–upper (LU) decomposition or factorization factors a matrix as the product of a lower triangular matrix and an upper triangular matrix (see matrix multiplication and matrix decomposition). The produ ...
.


Geometry

The Leibniz formula for states that :1 \,-\, \frac \,+\, \frac \,-\, \frac \,+\, \cdots \,=\, \frac. Leibniz wrote that circles "can most simply be expressed by this series, that is, the aggregate of fractions alternately added and subtracted". However this formula is only accurate with a large number of terms, using 10,000,000 terms to obtain the correct value of to 8 decimal places. Leibniz attempted to create a definition for a straight line while attempting to prove the
parallel postulate In geometry, the parallel postulate is the fifth postulate in Euclid's ''Elements'' and a distinctive axiom in Euclidean geometry. It states that, in two-dimensional geometry: If a line segment intersects two straight lines forming two interior ...
. While most mathematicians defined a straight line as the shortest line between two points, Leibniz believed that this was merely a property of a straight line rather than the definition.


Calculus

Leibniz is credited, along with
Isaac Newton Sir Isaac Newton () was an English polymath active as a mathematician, physicist, astronomer, alchemist, theologian, and author. Newton was a key figure in the Scientific Revolution and the Age of Enlightenment, Enlightenment that followed ...
, with the invention of
calculus Calculus is the mathematics, mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithmetic operations. Originally called infinitesimal calculus or "the ...
(differential and integral calculus). According to Leibniz's notebooks, a critical breakthrough occurred on 11 November 1675, when he employed integral calculus for the first time to find the area under the graph of a function . He introduced several notations used to this day, for instance the
integral sign The integral symbol (''see below'') is used to denote integrals and antiderivatives in mathematics, especially in calculus. History The notation was introduced by the German mathematician Gottfried Wilhelm Leibniz in 1675 in his private w ...
(\displaystyle\int f(x)\,dx), representing an elongated S, from the Latin word ''summa'', and the used for differentials (\frac), from the Latin word ''differentia''. Leibniz did not publish anything about his calculus until 1684. Leibniz expressed the inverse relation of integration and differentiation, later called the
fundamental theorem of calculus The fundamental theorem of calculus is a theorem that links the concept of derivative, differentiating a function (mathematics), function (calculating its slopes, or rate of change at every point on its domain) with the concept of integral, inte ...
, by means of a figure in his 1693 paper ''Supplementum geometriae dimensoriae...''. However, James Gregory is credited for the theorem's discovery in geometric form,
Isaac Barrow Isaac Barrow (October 1630 – 4 May 1677) was an English Christian theologian and mathematician who is generally given credit for his early role in the development of infinitesimal calculus; in particular, for proof of the fundamental theorem ...
proved a more generalized geometric version, and Newton developed supporting theory. The concept became more transparent as developed through Leibniz's formalism and new notation. The
product rule In calculus, the product rule (or Leibniz rule or Leibniz product rule) is a formula used to find the derivatives of products of two or more functions. For two functions, it may be stated in Lagrange's notation as (u \cdot v)' = u ' \cdot v ...
of
differential calculus In mathematics, differential calculus is a subfield of calculus that studies the rates at which quantities change. It is one of the two traditional divisions of calculus, the other being integral calculus—the study of the area beneath a curve. ...
is still called "Leibniz's law". In addition, the theorem that tells how and when to differentiate under the integral sign is called the
Leibniz integral rule In calculus, the Leibniz integral rule for differentiation under the integral sign, named after Gottfried Wilhelm Leibniz, states that for an integral of the form \int_^ f(x,t)\,dt, where -\infty < a(x), b(x) < \infty and the integrands ...
. Leibniz exploited
infinitesimal In mathematics, an infinitesimal number is a non-zero quantity that is closer to 0 than any non-zero real number is. The word ''infinitesimal'' comes from a 17th-century Modern Latin coinage ''infinitesimus'', which originally referred to the " ...
s in developing calculus, manipulating them in ways suggesting that they had
paradox A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true or apparently true premises, leads to a seemingly self-contradictor ...
ical
algebra Algebra is a branch of mathematics that deals with abstract systems, known as algebraic structures, and the manipulation of expressions within those systems. It is a generalization of arithmetic that introduces variables and algebraic ope ...
ic properties.
George Berkeley George Berkeley ( ; 12 March 168514 January 1753), known as Bishop Berkeley (Bishop of Cloyne of the Anglican Church of Ireland), was an Anglo-Irish philosopher, writer, and clergyman who is regarded as the founder of "immaterialism", a philos ...
, in a tract called ''
The Analyst ''The Analyst'' (subtitled ''A Discourse Addressed to an Infidel Mathematician: Wherein It Is Examined Whether the Object, Principles, and Inferences of the Modern Analysis Are More Distinctly Conceived, or More Evidently Deduced, Than Religious ...
'' and also in ''De Motu'', criticized these. A recent study argues that Leibnizian calculus was free of contradictions, and was better grounded than Berkeley's empiricist criticisms. Leibniz introduced
fractional calculus Fractional calculus is a branch of mathematical analysis that studies the several different possibilities of defining real number powers or complex number powers of the differentiation operator D D f(x) = \frac f(x)\,, and of the integration ...
in a letter written to
Guillaume de l'Hôpital Guillaume François Antoine, Marquis de l'Hôpital (; sometimes spelled L'Hospital; 7 June 1661 – 2 February 1704) was a French mathematician. His name is firmly associated with l'Hôpital's rule for calculating limits involving indetermin ...
in 1695. At the same time, Leibniz wrote to
Johann Bernoulli Johann Bernoulli (also known as Jean in French or John in English; – 1 January 1748) was a Swiss people, Swiss mathematician and was one of the many prominent mathematicians in the Bernoulli family. He is known for his contributions to infin ...
about derivatives of "general order". In the correspondence between Leibniz and
John Wallis John Wallis (; ; ) was an English clergyman and mathematician, who is given partial credit for the development of infinitesimal calculus. Between 1643 and 1689 Wallis served as chief cryptographer for Parliament and, later, the royal court. ...
in 1697, Wallis's infinite product for \fracπ is discussed. Leibniz suggested using differential calculus to achieve this result. Leibniz further used the notation ^ to denote the derivative of order \frac. From 1711 until his death, Leibniz was engaged in a dispute with
John Keill John Keill FRS (1 December 1671 – 31 August 1721) was a Scottish mathematician, natural philosopher, and cryptographer who was an important defender of Isaac Newton. Biography Keill was born in Edinburgh, Scotland on 1 December 1671. His fa ...
, Newton and others, over whether Leibniz had invented calculus independently of Newton. The use of infinitesimals in mathematics was frowned upon by followers of
Karl Weierstrass Karl Theodor Wilhelm Weierstrass (; ; 31 October 1815 – 19 February 1897) was a German mathematician often cited as the " father of modern analysis". Despite leaving university without a degree, he studied mathematics and trained as a school t ...
, but survived in science and engineering, and even in rigorous mathematics, via the fundamental computational device known as the differential. Beginning in 1960,
Abraham Robinson Abraham Robinson (born Robinsohn; October 6, 1918 – April 11, 1974) was a mathematician who is most widely known for development of nonstandard analysis, a mathematically rigorous system whereby infinitesimal and infinite numbers were reincorp ...
worked out a rigorous foundation for Leibniz's infinitesimals, using
model theory In mathematical logic, model theory is the study of the relationship between theory (mathematical logic), formal theories (a collection of Sentence (mathematical logic), sentences in a formal language expressing statements about a Structure (mat ...
, in the context of a field of
hyperreal number In mathematics, hyperreal numbers are an extension of the real numbers to include certain classes of infinite and infinitesimal numbers. A hyperreal number x is said to be finite if, and only if, , x, for some integer n
s. The resulting
non-standard analysis The history of calculus is fraught with philosophical debates about the meaning and logical validity of fluxions or infinitesimal numbers. The standard way to resolve these debates is to define the operations of calculus using (ε, δ)-definitio ...
can be seen as a belated vindication of Leibniz's mathematical reasoning. Robinson's
transfer principle In model theory, a transfer principle states that all statements of some language that are true for some structure are true for another structure. One of the first examples was the Lefschetz principle, which states that any sentence in the firs ...
is a mathematical implementation of Leibniz's heuristic
law of continuity Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior, with its precise definition a matter of longstanding debate. It has been variously described as a science and as the ar ...
, while the
standard part function In nonstandard analysis, the standard part function is a function from the limited (finite) hyperreal numbers to the real numbers. Briefly, the standard part function "rounds off" a finite hyperreal to the nearest real. It associates to every suc ...
implements the Leibnizian
transcendental law of homogeneity In mathematics, the transcendental law of homogeneity (TLH) is a heuristic principle enunciated by Gottfried Wilhelm Leibniz most clearly in a 1710 text entitled ''Symbolismus memorabilis calculi algebraici et infinitesimalis in comparatione potent ...
.


Topology

Leibniz was the first to use the term ''analysis situs'', later used in the 19th century to refer to what is now known as
topology Topology (from the Greek language, Greek words , and ) is the branch of mathematics concerned with the properties of a Mathematical object, geometric object that are preserved under Continuous function, continuous Deformation theory, deformat ...
. There are two takes on this situation. On the one hand, Mates, citing a 1954 paper in German by
Jacob Freudenthal Jacob Freudenthal (20 June 1839 – 1 June 1907) was a German philosopher. He was born at Bodenfelde, Kingdom of Hanover and died at Schreiberhau. Life Freudenthal was educated at the universities of Breslau and Göttingen, and at the rabbinic ...
, argues: But Hideaki Hirano argues differently, quoting Mandelbrot: Thus the
fractal geometry In mathematics, a fractal is a geometric shape containing detailed structure at arbitrarily small scales, usually having a fractal dimension strictly exceeding the topological dimension. Many fractals appear similar at various scales, as ...
promoted by Mandelbrot drew on Leibniz's notions of
self-similarity In mathematics, a self-similar object is exactly or approximately similar to a part of itself (i.e., the whole has the same shape as one or more of the parts). Many objects in the real world, such as coastlines, are statistically self-similar ...
and the principle of continuity: ''
Natura non facit saltus ''Natura non facit saltus'' Alexander Baumgarten, ''Metaphysics: A Critical Translation with Kant's Elucidations'', Translated and Edited by Courtney D. Fugate and John Hymers, Bloomsbury, 2013, "Preface of the Third Edition (1750)"p. 79 n. d " a ...
''. We also see that when Leibniz wrote, in a metaphysical vein, that "the straight line is a curve, any part of which is similar to the whole", he was anticipating topology by more than two centuries. As for "packing", Leibniz told his friend and correspondent Des Bosses to imagine a circle, then to inscribe within it three congruent circles with maximum radius; the latter smaller circles could be filled with three even smaller circles by the same procedure. This process can be continued infinitely, from which arises a good idea of self-similarity. Leibniz's improvement of Euclid's axiom contains the same concept. He envisioned the field of
combinatorial topology In mathematics, combinatorial topology was an older name for algebraic topology, dating from the time when topological invariants of spaces (for example the Betti numbers) were regarded as derived from combinatorial decompositions of spaces, such a ...
as early as 1679, in his work titled ''Characteristica Geometrica,'' as he "tried to formulate basic geometric properties of figures, to use special symbols to represent them, and to combine these properties under operations so as to produce new ones."


Science and engineering

Leibniz's writings are currently discussed, not only for their anticipations and possible discoveries not yet recognized, but as ways of advancing present knowledge. Much of his writing on physics is included in Gerhardt's ''Mathematical Writings''.


Physics

Leibniz contributed a fair amount to the statics and dynamics emerging around him, often disagreeing with Descartes and Newton. He devised a new theory of
motion In physics, motion is when an object changes its position with respect to a reference point in a given time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and frame of reference to an o ...
( dynamics) based on
kinetic energy In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Rober ...
and
potential energy In physics, potential energy is the energy of an object or system due to the body's position relative to other objects, or the configuration of its particles. The energy is equal to the work done against any restoring forces, such as gravity ...
, which posited space as relative, whereas Newton was thoroughly convinced that space was absolute. An important example of Leibniz's mature physical thinking is his ''Specimen Dynamicum'' of 1695. Until the discovery of subatomic particles and the
quantum mechanics Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...
governing them, many of Leibniz's speculative ideas about aspects of nature not reducible to statics and dynamics made little sense. For instance, he anticipated
Albert Einstein Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence f ...
by arguing, against Newton, that
space Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless ...
, time and motion are relative, not absolute: "As for my own opinion, I have said more than once, that I hold space to be something merely relative, as time is, that I hold it to be an order of coexistences, as time is an order of successions." Leibniz held a relational notion of space and time, against Newton's substantivalist views. According to Newton's substantivalism, space and time are entities in their own right, existing independently of things. Leibniz's relationalism, in contrast, describes
space and time In physics, spacetime, also called the space-time continuum, is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualizing ...
as systems of relations that exist between objects. The rise of
general relativity General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of grav ...
and subsequent work in the
history of physics Physics is a branch of science in which the primary objects of study are matter and energy. These topics were discussed across many cultures in ancient times by philosophers, but they had no means to distinguish causes of natural phenomena fro ...
has put Leibniz's stance in a more favorable light. One of Leibniz's projects was to recast Newton's theory as a vortex theory.Arthur 2014, p. 56. However, his project went beyond vortex theory, since at its heart there was an attempt to explain one of the most difficult problems in physics, that of the origin of the cohesion of matter. The
principle of sufficient reason The principle of sufficient reason states that everything must have a Reason (argument), reason or a cause. The principle was articulated and made prominent by Gottfried Wilhelm Leibniz, with many antecedents, and was further used and developed by ...
has been invoked in recent
cosmology Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe, the cosmos. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', with the meaning of "a speaking of the wo ...
, and his
identity of indiscernibles The identity of indiscernibles is an ontological principle that states that there cannot be separate objects or entities that have all their properties in common. That is, entities ''x'' and ''y'' are identical if every predicate possessed by ...
in quantum mechanics, a field some even credit him with having anticipated in some sense. In addition to his theories about the nature of reality, Leibniz's contributions to the development of calculus have also had a major impact on physics.


The ''vis viva''

Leibniz's ''
vis viva ''Vis viva'' (from the Latin for "living force") is a historical term used to describe a quantity similar to kinetic energy in an early formulation of the principle of conservation of energy. Overview Proposed by Gottfried Leibniz over the period ...
'' (Latin for "living force") is , twice the modern
kinetic energy In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Rober ...
. He realized that the total energy would be conserved in certain mechanical systems, so he considered it an innate motive characteristic of matter. Here too his thinking gave rise to another regrettable nationalistic dispute. His ''vis viva'' was seen as rivaling the
conservation of momentum In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. ...
championed by Newton in England and by Descartes and Voltaire in France; hence
academic An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the go ...
s in those countries tended to neglect Leibniz's idea. Leibniz knew of the validity of conservation of momentum. In reality, both energy and
momentum In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. ...
are conserved (in
closed systems A closed system is a natural physical system that does not allow transfer of matter in or out of the system, althoughin the contexts of physics, chemistry, engineering, etc.the transfer of energy (e.g. as work or heat) is allowed. Physics In cl ...
), so both approaches are valid.


Other natural science

By proposing that the Earth has a molten core, he anticipated modern geology. In
embryology Embryology (from Ancient Greek, Greek ἔμβρυον, ''embryon'', "the unborn, embryo"; and -λογία, ''-logy, -logia'') is the branch of animal biology that studies the Prenatal development (biology), prenatal development of gametes (sex ...
, he was a preformationist, but also proposed that organisms are the outcome of a combination of an infinite number of possible microstructures and of their powers. In the
life sciences This list of life sciences comprises the branches of science that involve the scientific study of life – such as microorganisms, plants, and animals including human beings. This science is one of the two major branches of natural science, ...
and
paleontology Paleontology, also spelled as palaeontology or palæontology, is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure ge ...
, he revealed an amazing transformist intuition, fueled by his study of comparative anatomy and fossils. One of his principal works on this subject, ''
Protogaea ''Protogaea'' is a work by Gottfried Leibniz on geology and natural history. Unpublished in his lifetime, but made known by Johann Georg von Eckhart in 1719, it was conceived as a preface to his incomplete history of the House of Brunswick. Lif ...
'', unpublished in his lifetime, has recently been published in English for the first time. He worked out a primal
organismic theory Organismic theories in psychology are a family of holistic psychological theories which tend to stress the organization, unity, and integration of human beings expressed through each individual's inherent growth or developmental tendency. The id ...
. In medicine, he exhorted the physicians of his time—with some results—to ground their theories in detailed comparative observations and verified experiments, and to distinguish firmly scientific and metaphysical points of view.


Psychology

Psychology had been a central interest of Leibniz. He appears to be an "underappreciated pioneer of psychology" He wrote on topics which are now regarded as fields of psychology:
attention Attention or focus, is the concentration of awareness on some phenomenon to the exclusion of other stimuli. It is the selective concentration on discrete information, either subjectively or objectively. William James (1890) wrote that "Atte ...
and
consciousness Consciousness, at its simplest, is awareness of a state or object, either internal to oneself or in one's external environment. However, its nature has led to millennia of analyses, explanations, and debate among philosophers, scientists, an ...
,
memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...
,
learning Learning is the process of acquiring new understanding, knowledge, behaviors, skills, value (personal and cultural), values, Attitude (psychology), attitudes, and preferences. The ability to learn is possessed by humans, non-human animals, and ...
(
association Association may refer to: *Club (organization), an association of two or more people united by a common interest or goal *Trade association, an organization founded and funded by businesses that operate in a specific industry *Voluntary associatio ...
),
motivation Motivation is an mental state, internal state that propels individuals to engage in goal-directed behavior. It is often understood as a force that explains why people or animals initiate, continue, or terminate a certain behavior at a particul ...
(the act of "striving"), emergent
individuality An individual is one that exists as a distinct entity. Individuality (or self-hood) is the state or quality of living as an individual; particularly (in the case of humans) as a person unique from other people and possessing one's own needs or g ...
, the general dynamics of development (
evolutionary psychology Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regard to the ancestral problems they evolved ...
). His discussions in the ''New Essays'' and ''Monadology'' often rely on everyday observations such as the behaviour of a dog or the noise of the sea, and he develops intuitive analogies (the synchronous running of clocks or the balance spring of a clock). He also devised postulates and principles that apply to psychology: the continuum of the unnoticed ''petites perceptions'' to the distinct, self-aware
apperception Apperception (from the Latin ''ad-'', "to, toward" and ''percipere'', "to perceive, gain, secure, learn, or feel") is any of several aspects of perception and consciousness in such fields as psychology, philosophy and epistemology. Meaning in phil ...
, and
psychophysical parallelism In the philosophy of mind, psychophysical parallelism (or simply parallelism) is the theory that mental and bodily events are perfectly coordinated, without any causal interaction between them. As such, it affirms the correlation of mental and bod ...
from the point of view of causality and of purpose: "Souls act according to the laws of final causes, through aspirations, ends and means. Bodies act according to the laws of efficient causes, i.e. the laws of motion. And these two realms, that of efficient causes and that of final causes, harmonize with one another." This idea refers to the mind-body problem, stating that the mind and brain do not act upon each other, but act alongside each other separately but in harmony. Leibniz, however, did not use the term ''psychologia''. Leibniz's epistemological position—against
John Locke John Locke (; 29 August 1632 (Old Style and New Style dates, O.S.) – 28 October 1704 (Old Style and New Style dates, O.S.)) was an English philosopher and physician, widely regarded as one of the most influential of the Enlightenment thi ...
and English
empiricism In philosophy, empiricism is an epistemological view which holds that true knowledge or justification comes only or primarily from sensory experience and empirical evidence. It is one of several competing views within epistemology, along ...
(
sensualism In epistemology, sensualism is a doctrine whereby sensations and perception are the basic and most important form of true cognition. It may oppose abstract ideas. This ideogenetic question was long ago put forward in Greek philosophy (Stoicism, ...
)—was made clear: "Nihil est in intellectu quod non fuerit in sensu, nisi intellectu ipse." – "Nothing is in the intellect that was not first in the senses, except the intellect itself." Principles that are not present in sensory impressions can be recognised in human perception and consciousness: logical inferences, categories of thought, the principle of causality and the principle of purpose (
teleology Teleology (from , and )Partridge, Eric. 1977''Origins: A Short Etymological Dictionary of Modern English'' London: Routledge, p. 4187. or finalityDubray, Charles. 2020 912Teleology. In ''The Catholic Encyclopedia'' 14. New York: Robert Appleton ...
). Leibniz found his most important interpreter in
Wilhelm Wundt Wilhelm Maximilian Wundt (; ; 16 August 1832 – 31 August 1920) was a German physiologist, philosopher, and professor, one of the fathers of modern psychology. Wundt, who distinguished psychology as a science from philosophy and biology, was t ...
, founder of psychology as a discipline. Wundt used the "… nisi intellectu ipse" quotation 1862 on the title page of his ''Beiträge zur Theorie der Sinneswahrnehmung'' (Contributions on the Theory of Sensory Perception) and published a detailed and aspiring monograph on Leibniz. Wundt shaped the term
apperception Apperception (from the Latin ''ad-'', "to, toward" and ''percipere'', "to perceive, gain, secure, learn, or feel") is any of several aspects of perception and consciousness in such fields as psychology, philosophy and epistemology. Meaning in phil ...
, introduced by Leibniz, into an experimental psychologically based apperception psychology that included neuropsychological modelling – an excellent example of how a concept created by a great philosopher could stimulate a psychological research program. One principle in the thinking of Leibniz played a fundamental role: "the principle of equality of separate but corresponding viewpoints." Wundt characterized this style of thought (
perspectivism Perspectivism (also called perspectivalism) is the epistemological principle that perception of and knowledge of something are always bound to the interpretive perspectives of those observing it. While perspectivism regard all perspectives and ...
) in a way that also applied for him—viewpoints that "supplement one another, while also being able to appear as opposites that only resolve themselves when considered more deeply." Much of Leibniz's work went on to have a great impact on the field of psychology. Leibniz thought that there are many petites perceptions, or small perceptions of which we perceive but of which we are unaware. He believed that by the principle that phenomena found in nature were continuous by default, it was likely that the transition between conscious and unconscious states had intermediary steps. For this to be true, there must also be a portion of the mind of which we are unaware at any given time. His theory regarding consciousness in relation to the principle of continuity can be seen as an early theory regarding the
stages of sleep Sleep is a state of reduced mental and physical activity in which consciousness is altered and certain sensory activity is inhibited. During sleep, there is a marked decrease in muscle activity and interactions with the surrounding environme ...
. In this way, Leibniz's theory of perception can be viewed as one of many theories leading up to the idea of the
unconscious Unconscious may refer to: Physiology * Unconsciousness, the lack of consciousness or responsiveness to people and other environmental stimuli Psychology * Unconscious mind, the mind operating well outside the attention of the conscious mind a ...
. Leibniz was a direct influence on
Ernst Platner Ernst Platner (; ; 11 June 1744 – 27 December 1818) was a German anthropologist, physician and RationalistFrederick Beiser, ''The Fate of Reason: German Philosophy from Kant to Fichte'', Harvard University Press, 2009, p. 214. philosopher ...
, who is credited with originally coining the term Unbewußtseyn (unconscious). Additionally, the idea of
subliminal stimuli Subliminal stimuli (; ' literally "below" or "less than") are any sensory stimulus (physiology), stimuli below an individual's sensory threshold, threshold or limit for conscious perception, in contrast to stimuli (above threshold). Visual stimul ...
can be traced back to his theory of small perceptions. Leibniz's ideas regarding music and tonal perception went on to influence the laboratory studies of Wilhelm Wundt.


Social science

In public health, he advocated establishing a medical administrative authority, with powers over
epidemiology Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and Risk factor (epidemiology), determinants of health and disease conditions in a defined population, and application of this knowledge to prevent dise ...
and
veterinary medicine Veterinary medicine is the branch of medicine that deals with the prevention, management, medical diagnosis, diagnosis, and treatment of disease, disorder, and injury in non-human animals. The scope of veterinary medicine is wide, covering all a ...
. He worked to set up a coherent medical training program, oriented towards public health and preventive measures. In economic policy, he proposed tax reforms and a national insurance program, and discussed the
balance of trade Balance of trade is the difference between the monetary value of a nation's exports and imports of goods over a certain time period. Sometimes, trade in Service (economics), services is also included in the balance of trade but the official IMF d ...
. He even proposed something akin to what much later emerged as
game theory Game theory is the study of mathematical models of strategic interactions. It has applications in many fields of social science, and is used extensively in economics, logic, systems science and computer science. Initially, game theory addressed ...
. In sociology he laid the ground for
communication theory Communication theory is a proposed description of communication phenomena, the relationships among them, a storyline describing these relationships, and an argument for these three elements. Communication theory provides a way of talking about a ...
.


Technology

In 1906, Garland published a volume of Leibniz's writings bearing on his many practical inventions and engineering work. To date, few of these writings have been translated into English. Nevertheless, it is well understood that Leibniz was a serious inventor, engineer, and applied scientist, with great respect for practical life. Following the motto ''theoria cum praxi'', he urged that theory be combined with practical application, and thus has been claimed as the father of
applied science Applied science is the application of the scientific method and scientific knowledge to attain practical goals. It includes a broad range of disciplines, such as engineering and medicine. Applied science is often contrasted with basic science, ...
. He designed wind-driven propellers and water pumps, mining machines to extract ore, hydraulic presses, lamps, submarines, clocks, etc. With
Denis Papin Denis Papin FRS (; 22 August 1647 – 26 August 1713) was a French physicist, mathematician and inventor, best known for his pioneering invention of the steam digester, the forerunner of the pressure cooker, the steam engine, the centrifug ...
, he created a
steam engine A steam engine is a heat engine that performs Work (physics), mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a Cylinder (locomotive), cyl ...
. He even proposed a method for desalinating water. From 1680 to 1685, he struggled to overcome the chronic flooding that afflicted the ducal silver mines in the
Harz Mountains The Harz (), also called the Harz Mountains, is a Mittelgebirge, highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The nam ...
, but did not succeed.


Computation

Leibniz may have been the first computer scientist and information theorist. Early in life, he documented the
binary numeral system A binary number is a number expressed in the base-2 numeral system or binary numeral system, a method for representing numbers that uses only two symbols for the natural numbers: typically "0" ( zero) and "1" ( one). A ''binary number'' may als ...
( base 2), then revisited that system throughout his career. While Leibniz was examining other cultures to compare his metaphysical views, he encountered an ancient Chinese book ''
I Ching The ''I Ching'' or ''Yijing'' ( ), usually translated ''Book of Changes'' or ''Classic of Changes'', is an ancient Chinese divination text that is among the oldest of the Chinese classics. The ''I Ching'' was originally a divination manual in ...
''. Leibniz interpreted a diagram which showed yin and yang and corresponded it to a zero and one. More information can be found in the Sinophilia section. Leibniz had similarities with
Juan Caramuel y Lobkowitz ''Juan'' is a given name, the Spanish and Manx versions of '' John''. The name is of Hebrew origin and has the meaning "God has been gracious." It is very common in Spain and in other Spanish-speaking countries around the world and in the Phili ...
and
Thomas Harriot Thomas Harriot (; – 2 July 1621), also spelled Harriott, Hariot or Heriot, was an English astronomer, mathematician, ethnographer and translator to whom the theory of refraction is attributed. Thomas Harriot was also recognized for his con ...
, who independently developed the binary system, as he was familiar with their works on the binary system. Juan Caramuel y Lobkowitz worked extensively on logarithms including logarithms with base 2. Thomas Harriot's manuscripts contained a table of binary numbers and their notation, which demonstrated that any number could be written on a base 2 system. Regardless, Leibniz simplified the binary system and articulated logical properties such as conjunction, disjunction, negation, identity, inclusion, and the empty set. He anticipated Lagrangian interpolation and algorithmic information theory. His
calculus ratiocinator The ''calculus ratiocinator'' is a theoretical universal logical calculation framework, a concept described in the writings of Gottfried Leibniz, usually paired with his more frequently mentioned ''characteristica universalis'', a universal conc ...
anticipated aspects of the
universal Turing machine In computer science, a universal Turing machine (UTM) is a Turing machine capable of computing any computable sequence, as described by Alan Turing in his seminal paper "On Computable Numbers, with an Application to the Entscheidungsproblem". Co ...
. In 1961,
Norbert Wiener Norbert Wiener (November 26, 1894 – March 18, 1964) was an American computer scientist, mathematician, and philosopher. He became a professor of mathematics at the Massachusetts Institute of Technology ( MIT). A child prodigy, Wiener late ...
suggested that Leibniz should be considered the patron saint of
cybernetics Cybernetics is the transdisciplinary study of circular causal processes such as feedback and recursion, where the effects of a system's actions (its outputs) return as inputs to that system, influencing subsequent action. It is concerned with ...
. Wiener is quoted with "Indeed, the general idea of a computing machine is nothing but a mechanization of Leibniz's Calculus Ratiocinator." In 1671, Leibniz began to invent a machine that could execute all four arithmetic operations, gradually improving it over a number of years. This " stepped reckoner" attracted fair attention and was the basis of his election to the
Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
in 1673. A number of such machines were made during his years in
Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...
by a craftsman working under his supervision. They were not an unambiguous success because they did not fully mechanize the carry operation. Couturat reported finding an unpublished note by Leibniz, dated 1674, describing a machine capable of performing some algebraic operations. Leibniz also devised a (now reproduced) cipher machine, recovered by
Nicholas Rescher Nicholas Rescher (; ; 15 July 1928 – 5 January 2024) was a German-born American philosopher, polymath, and author, who was a professor of philosophy at the University of Pittsburgh from 1961. He was chairman of the Center for Philosophy of Sc ...
in 2010. In 1693, Leibniz described a design of a machine which could, in theory, integrate differential equations, which he called "integraph". Leibniz was groping towards hardware and software concepts worked out much later by
Charles Babbage Charles Babbage (; 26 December 1791 – 18 October 1871) was an English polymath. A mathematician, philosopher, inventor and mechanical engineer, Babbage originated the concept of a digital programmable computer. Babbage is considered ...
and
Ada Lovelace Augusta Ada King, Countess of Lovelace (''née'' Byron; 10 December 1815 – 27 November 1852), also known as Ada Lovelace, was an English mathematician and writer chiefly known for her work on Charles Babbage's proposed mechanical general-pur ...
. In 1679, while mulling over his binary arithmetic, Leibniz imagined a machine in which binary numbers were represented by marbles, governed by a rudimentary sort of punched cards. Modern electronic digital computers replace Leibniz's marbles moving by gravity with shift registers, voltage gradients, and pulses of electrons, but otherwise they run roughly as Leibniz envisioned in 1679.


Librarian

Later in Leibniz's career (after the death of von Boyneburg), Leibniz moved to Paris and accepted a position as a librarian in the Hanoverian court of Johann Friedrich, Duke of Brunswick-Luneburg. Leibniz's predecessor, Tobias Fleischer, had already created a cataloging system for the Duke's library but it was a clumsy attempt. At this library, Leibniz focused more on advancing the library than on the cataloging. For instance, within a month of taking the new position, he developed a comprehensive plan to expand the library. He was one of the first to consider developing a core collection for a library and felt "that a library for display and ostentation is a luxury and indeed superfluous, but a well-stocked and organized library is important and useful for all areas of human endeavor and is to be regarded on the same level as schools and churches". Leibniz lacked the funds to develop the library in this manner. After working at this library, by the end of 1690 Leibniz was appointed as privy-councilor and librarian of the Bibliotheca Augusta at Wolfenbüttel. It was an extensive library with at least 25,946 printed volumes. At this library, Leibniz sought to improve the catalog. He was not allowed to make complete changes to the existing closed catalog, but was allowed to improve upon it so he started on that task immediately. He created an alphabetical author catalog and had also created other cataloging methods that were not implemented. While serving as librarian of the ducal libraries in
Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...
and
Wolfenbüttel Wolfenbüttel (; ) is a town in Lower Saxony, Germany, the administrative capital of Wolfenbüttel District Wolfenbüttel (; ) is a town in Lower Saxony, Germany, the administrative capital of Wolfenbüttel (district), Wolfenbüttel Distri ...
, Leibniz effectively became one of the founders of
library science Library and information science (LIS)Library and Information Sciences is the name used in the Dewey Decimal Classification for class 20 from the 18th edition (1971) to the 22nd edition (2003). are two interconnected disciplines that deal with info ...
. Seemingly, Leibniz paid a good deal of attention to the classification of subject matter, favoring a well-balanced library covering a host of numerous subjects and interests. Leibniz, for example, proposed the following classification system in the ''Otivm Hanoveranvm Sive Miscellanea'' (1737): * Theology * Jurisprudence * Medicine * Intellectual Philosophy * Philosophy of the Imagination or Mathematics * Philosophy of Sensible Things or Physics * Philology or Language * Civil History * Literary History and Libraries * General and Miscellaneous He also designed a book indexing system in ignorance of the only other such system then extant, that of the
Bodleian Library The Bodleian Library () is the main research library of the University of Oxford. Founded in 1602 by Sir Thomas Bodley, it is one of the oldest libraries in Europe. With over 13 million printed items, it is the second-largest library in ...
at
Oxford University The University of Oxford is a collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the second-oldest continuously operating u ...
. He also called on publishers to distribute abstracts of all new titles they produced each year, in a standard form that would facilitate indexing. He hoped that this abstracting project would eventually include everything printed from his day back to
Gutenberg Johannes Gensfleisch zur Laden zum Gutenberg ( – 3 February 1468) was a German inventor and craftsman who invented the movable-type printing press. Though movable type was already in use in East Asia, Gutenberg's invention of the printing ...
. Neither proposal met with success at the time, but something like them became standard practice among English language publishers during the 20th century, under the aegis of the
Library of Congress The Library of Congress (LOC) is a research library in Washington, D.C., serving as the library and research service for the United States Congress and the ''de facto'' national library of the United States. It also administers Copyright law o ...
and the
British Library The British Library is the national library of the United Kingdom. Based in London, it is one of the largest libraries in the world, with an estimated collection of between 170 and 200 million items from multiple countries. As a legal deposit li ...
. He called for the creation of an
empirical Empirical evidence is evidence obtained through sense experience or experimental procedure. It is of central importance to the sciences and plays a role in various other fields, like epistemology and law. There is no general agreement on how t ...
database In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...
as a way to further all sciences. His ''
characteristica universalis The Latin term ''characteristica universalis'', commonly interpreted as ''universal characteristic'', or ''universal character'' in English, is a universal and formal language imagined by Gottfried Leibniz able to express mathematical, scienti ...
'',
calculus ratiocinator The ''calculus ratiocinator'' is a theoretical universal logical calculation framework, a concept described in the writings of Gottfried Leibniz, usually paired with his more frequently mentioned ''characteristica universalis'', a universal conc ...
, and a "community of minds"—intended, among other things, to bring political and religious unity to Europe—can be seen as distant unwitting anticipations of artificial languages (e.g.,
Esperanto Esperanto (, ) is the world's most widely spoken Constructed language, constructed international auxiliary language. Created by L. L. Zamenhof in 1887 to be 'the International Language' (), it is intended to be a universal second language for ...
and its rivals),
symbolic logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o ...
, even the
World Wide Web The World Wide Web (WWW or simply the Web) is an information system that enables Content (media), content sharing over the Internet through user-friendly ways meant to appeal to users beyond Information technology, IT specialists and hobbyis ...
.


Advocate of scientific societies

Leibniz emphasized that research was a collaborative endeavor. Hence he warmly advocated the formation of national scientific societies along the lines of the British Royal Society and the French Académie Royale des Sciences. More specifically, in his correspondence and travels he urged the creation of such societies in Dresden,
Saint Petersburg Saint Petersburg, formerly known as Petrograd and later Leningrad, is the List of cities and towns in Russia by population, second-largest city in Russia after Moscow. It is situated on the Neva, River Neva, at the head of the Gulf of Finland ...
, Vienna, and Berlin. Only one such project came to fruition; in 1700, the Berlin Academy of Sciences was created. Leibniz drew up its first statutes, and served as its first President for the remainder of his life. That Academy evolved into the German Academy of Sciences, the publisher of the ongoing critical edition of his works.


Law and morality

Leibniz's writings on law, ethics, and politics were long overlooked by English-speaking scholars, but this has changed of late. While Leibniz was no apologist for absolute monarchy like
Hobbes Thomas Hobbes ( ; 5 April 1588 – 4 December 1679) was an English philosopher, best known for his 1651 book ''Leviathan'', in which he expounds an influential formulation of social contract theory. He is considered to be one of the founders ...
, or for tyranny in any form, neither did he echo the political and constitutional views of his contemporary
John Locke John Locke (; 29 August 1632 (Old Style and New Style dates, O.S.) – 28 October 1704 (Old Style and New Style dates, O.S.)) was an English philosopher and physician, widely regarded as one of the most influential of the Enlightenment thi ...
, views invoked in support of liberalism, in 18th-century America and later elsewhere. The following excerpt from a 1695 letter to Baron J. C. Boyneburg's son Philipp is very revealing of Leibniz's political sentiments: In 1677, Leibniz called for a European confederation, governed by a council or senate, whose members would represent entire nations and would be free to vote their consciences; this is sometimes considered an anticipation of the
European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...
. He believed that Europe would adopt a uniform religion. He reiterated these proposals in 1715. But at the same time, he arrived to propose an interreligious and multicultural project to create a universal system of justice, which required from him a broad interdisciplinary perspective. In order to propose it, he combined linguistics (especially sinology), moral and legal philosophy, management, economics, and politics.


Law

Leibniz trained as a legal academic, but under the tutelage of Cartesian-sympathiser
Erhard Weigel Erhard Weigel (; 16 December 1625 – 20 March 1699) was a German mathematician, astronomer and philosopher. Biography Weigel earned his Master of Arts, M.A. (1650) and his habilitation (1652) from the University of Leipzig. From 1653 until his d ...
we already see an attempt to solve legal problems by rationalist mathematical methods (Weigel's influence being most explicit in the ''Specimen Quaestionum Philosophicarum ex Jure collectarum'' (''An Essay of Collected Philosophical Problems of Right'')). For example, the ''Disputatio Inauguralis de Casibus Perplexis in Jure'' (''Inaugural Disputation on Ambiguous Legal Cases'') uses early combinatorics to solve some legal disputes, while the 1666 ''
De Arte Combinatoria The ''Dissertatio de arte combinatoria'' ("Dissertation on the Art of Combinations" or "On the Combinatorial Art") is an early work by Gottfried Leibniz published in 1666 in Leipzig. It is an extended version of his first doctoral dissertation, wr ...
'' (''On the Art of Combination'') includes simple legal problems by way of illustration. The use of combinatorial methods to solve legal and moral problems seems, via
Athanasius Kircher Athanasius Kircher (2 May 1602 – 27 November 1680) was a German Society of Jesus, Jesuit scholar and polymath who published around 40 major works of comparative religion, geology, and medicine. Kircher has been compared to fellow Jes ...
and
Daniel Schwenter Daniel Schwenter (Schwender) (31 January 1585 – 19 January 1636) was a German Orientalist, mathematician, inventor, poet, and librarian. Biography Schwenter was born in Nuremberg. He was professor of oriental languages and mathematics at ...
to be of Llullist inspiration:
Ramón Llull Ramon Llull (; ; – 1316), sometimes anglicized as ''Raymond Lully'', was a philosopher, theologian, poet, missionary, Christian apologist and former knight from the Kingdom of Majorca. He invented a philosophical system known as the ''Art'' ...
attempted to solve ecumenical disputes through recourse to a combinatorial mode of reasoning he regarded as universal (a mathesis universalis). In the late 1660s the enlightened Prince-Bishop of Mainz
Johann Philipp von Schönborn Johann, typically a male given name, is the German form of ''Iohannes'', which is the Latin form of the Greek name ''Iōánnēs'' (), itself derived from Hebrew name '' Yochanan'' () in turn from its extended form (), meaning "Yahweh is Gracious ...
announced a review of the legal system and made available a position to support his current law commissioner. Leibniz left Franconia and made for Mainz before even winning the role. On reaching
Frankfurt am Main Frankfurt am Main () is the most populous city in the States of Germany, German state of Hesse. Its 773,068 inhabitants as of 2022 make it the List of cities in Germany by population, fifth-most populous city in Germany. Located in the forela ...
Leibniz penned The New Method of Teaching and Learning the Law, by way of application. The text proposed a reform of legal education and is characteristically syncretic, integrating aspects of Thomism, Hobbesianism, Cartesianism and traditional jurisprudence. Leibniz's argument that the function of legal teaching was not to impress rules as one might train a dog, but to aid the student in discovering their own public reason, evidently impressed von Schönborn as he secured the job. Leibniz's next major attempt to find a universal rational core to law and so found a legal "science of right", came when Leibniz worked in Mainz from 1667–72. Starting initially from Hobbes' mechanistic doctrine of power, Leibniz reverted to logico-combinatorial methods in an attempt to define justice. As Leibniz's so-called Elementa Juris Naturalis advanced, he built in modal notions of right (possibility) and obligation (necessity) in which we see perhaps the earliest elaboration of his possible worlds doctrine within a deontic frame. While ultimately the Elementa remained unpublished, Leibniz continued to work on his drafts and promote their ideas to correspondents up until his death.


Ecumenism

Leibniz devoted considerable intellectual and diplomatic effort to what would now be called an
ecumenical Ecumenism ( ; alternatively spelled oecumenism)also called interdenominationalism, or ecumenicalismis the concept and principle that Christians who belong to different Christian denominations should work together to develop closer relationships ...
endeavor, seeking to reconcile the
Roman Catholic The Catholic Church (), also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institut ...
and
Lutheran Lutheranism is a major branch of Protestantism that emerged under the work of Martin Luther, the 16th-century German friar and Protestant Reformers, reformer whose efforts to reform the theology and practices of the Catholic Church launched ...
churches. In this respect, he followed the example of his early patrons, Baron von Boyneburg and the Duke John Frederickboth cradle Lutherans who converted to Catholicism as adultswho did what they could to encourage the reunion of the two faiths, and who warmly welcomed such endeavors by others. (The House of Brunswick remained Lutheran, because the Duke's children did not follow their father.) These efforts included corresponding with French bishop
Jacques-Bénigne Bossuet Jacques-Bénigne Lignel Bossuet (; 27 September 1627 – 12 April 1704) was a French Bishop (Catholic Church), bishop and theology, theologian. Renowned for his sermons, addresses and literary works, he is regarded as a brilliant orator and lit ...
, and involved Leibniz in some theological controversy. He evidently thought that the thoroughgoing application of reason would suffice to heal the breach caused by the
Reformation The Reformation, also known as the Protestant Reformation or the European Reformation, was a time of major Theology, theological movement in Western Christianity in 16th-century Europe that posed a religious and political challenge to the p ...
.


Philology

Leibniz the
philologist Philology () is the study of language in oral and written historical sources. It is the intersection of textual criticism, literary criticism, history, and linguistics with strong ties to etymology. Philology is also defined as the study of ...
was an avid student of languages, eagerly latching on to any information about vocabulary and grammar that came his way. In 1710, he applied ideas of
gradualism Gradualism, from the Latin ("step"), is a hypothesis, a theory or a tenet assuming that change comes about gradually or that variation is gradual in nature and happens over time as opposed to in large steps. Uniformitarianism, incrementalism, and ...
and
uniformitarianism Uniformitarianism, also known as the Doctrine of Uniformity or the Uniformitarian Principle, is the assumption that the same natural laws and processes that operate in our present-day scientific observations have always operated in the universe in ...
to linguistics in a short essay. He refuted the belief, widely held by Christian scholars of the time, that
Hebrew Hebrew (; ''ʿÎbrit'') is a Northwest Semitic languages, Northwest Semitic language within the Afroasiatic languages, Afroasiatic language family. A regional dialect of the Canaanite languages, it was natively spoken by the Israelites and ...
was the primeval language of the human race. At the same time, he rejected the idea of unrelated language groups and considered them all to have a common source. He also refuted the argument, advanced by Swedish scholars in his day, that a form of proto- Swedish was the ancestor of the
Germanic languages The Germanic languages are a branch of the Indo-European languages, Indo-European language family spoken natively by a population of about 515 million people mainly in Europe, North America, Oceania, and Southern Africa. The most widely spoke ...
. He puzzled over the origins of the
Slavic languages The Slavic languages, also known as the Slavonic languages, are Indo-European languages spoken primarily by the Slavs, Slavic peoples and their descendants. They are thought to descend from a proto-language called Proto-Slavic language, Proto- ...
and was fascinated by
classical Chinese Classical Chinese is the language in which the classics of Chinese literature were written, from . For millennia thereafter, the written Chinese used in these works was imitated and iterated upon by scholars in a form now called Literary ...
. Leibniz was also an expert in the
Sanskrit Sanskrit (; stem form ; nominal singular , ,) is a classical language belonging to the Indo-Aryan languages, Indo-Aryan branch of the Indo-European languages. It arose in northwest South Asia after its predecessor languages had Trans-cultural ...
language. He published the ''princeps editio'' (first modern edition) of the
late medieval The late Middle Ages or late medieval period was the period of European history lasting from 1300 to 1500 AD. The late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period (and in much of Europe, the Renai ...
''
Chronicon Holtzatiae The ''Chronicon Holtzatiae auctore presbytero Bremensi'' is a Latin universal chronicle from the year 1448, but concentrating on the County of Holstein (the ''terra Holsacie'') and written by an anonymous presbyter of Bremen originally from Hols ...
'', a Latin chronicle of the
County of Holstein Holstein (; ; ; ; ) is the region between the rivers Elbe and Eider. It is the southern half of Schleswig-Holstein, the northernmost state of Germany. Holstein once existed as the German County of Holstein (; 811–1474), the later Duchy of H ...
.


Sinophilia

Leibniz was perhaps the first major European intellectual to take a close interest in Chinese civilization, which he knew by corresponding with, and reading other works by, European Christian missionaries posted in China. He apparently read '' Confucius Sinarum Philosophus'' in the first year of its publication. He came to the conclusion that Europeans could learn much from the
Confucian Confucianism, also known as Ruism or Ru classicism, is a system of thought and behavior originating in ancient China, and is variously described as a tradition, philosophy, religion, theory of government, or way of life. Founded by Confucius ...
ethical tradition. He mulled over the possibility that the
Chinese characters Chinese characters are logographs used Written Chinese, to write the Chinese languages and others from regions historically influenced by Chinese culture. Of the four independently invented writing systems accepted by scholars, they represe ...
were an unwitting form of his
universal characteristic The Latin term ''characteristica universalis'', commonly interpreted as ''universal characteristic'', or ''universal character'' in English, is a universal and formal language imagined by Gottfried Leibniz able to express mathematical, scienti ...
. He noted how the ''
I Ching The ''I Ching'' or ''Yijing'' ( ), usually translated ''Book of Changes'' or ''Classic of Changes'', is an ancient Chinese divination text that is among the oldest of the Chinese classics. The ''I Ching'' was originally a divination manual in ...
'' hexagrams correspond to the
binary number A binary number is a number expressed in the Radix, base-2 numeral system or binary numeral system, a method for representing numbers that uses only two symbols for the natural numbers: typically "0" (zero) and "1" (one). A ''binary number'' may ...
s from 000000 to 111111, and concluded that this mapping was evidence of major Chinese accomplishments in the sort of philosophical mathematics he admired. Leibniz communicated his ideas of the binary system representing Christianity to the Emperor of China, hoping it would convert him. Leibniz was one of the western philosophers of the time who attempted to accommodate Confucian ideas to prevailing European beliefs. Leibniz's attraction to
Chinese philosophy Chinese philosophy (Simplified Chinese characters, simplified Chinese: 中国哲学; Traditional Chinese characters, traditional Chinese: 中國哲學) refers to the philosophical traditions that originated and developed within the historical ...
originates from his perception that Chinese philosophy was similar to his own. The historian E.R. Hughes suggests that Leibniz's ideas of "simple substance" and " pre-established harmony" were directly influenced by Confucianism, pointing to the fact that they were conceived during the period when he was reading ''Confucius Sinarum Philosophus''.


Polymath

While making his grand tour of European archives to research the Brunswick family history that he never completed, Leibniz stopped in Vienna between May 1688 and February 1689, where he did much legal and diplomatic work for the Brunswicks. He visited mines, talked with mine engineers, and tried to negotiate export contracts for lead from the ducal mines in the
Harz mountains The Harz (), also called the Harz Mountains, is a Mittelgebirge, highland area in northern Germany. It has the highest elevations for that region, and its rugged terrain extends across parts of Lower Saxony, Saxony-Anhalt, and Thuringia. The nam ...
. His proposal that the streets of Vienna be lit with lamps burning
rapeseed oil Close-up of canola blooms Canola flower Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historica ...
was implemented. During a formal audience with the
Austrian Emperor The emperor of Austria (, ) was the ruler of the Austrian Empire and later the Austro-Hungarian Empire. The hereditary imperial title and office was proclaimed in 1804 by Francis II, Holy Roman Emperor, a member of the House of Habsburg-Lorra ...
and in subsequent memoranda, he advocated reorganizing the Austrian economy, reforming the coinage of much of central Europe, negotiating a
Concordat A concordat () is a convention between the Holy See and a sovereign state that defines the relationship between the Catholic Church and the state in matters that concern both,René Metz, ''What is Canon Law?'' (New York: Hawthorn Books, 1960
Habsburg The House of Habsburg (; ), also known as the House of Austria, was one of the most powerful dynasties in the history of Europe and Western civilization. They were best known for their inbreeding and for ruling vast realms throughout Europe d ...
s and the Holy See">Vatican Vatican may refer to: Geography * Vatican City, an independent city-state surrounded by Rome, Italy * Vatican Hill, in Rome, namesake of Vatican City * Ager Vaticanus, an alluvial plain in Rome * Vatican, an unincorporated community in the ...
, and creating an imperial research library, official archive, and public insurance fund. He wrote and published an important paper on mechanics.


Posthumous reputation

When Leibniz died, his reputation was in decline. He was remembered for only one book, the ''
Théodicée (from French: ''Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil''), more simply known as , is a book of philosophy by the German polymath Gottfried Leibniz. The book, published in 1710, introduced the te ...
'', whose supposed central argument
Voltaire François-Marie Arouet (; 21 November 169430 May 1778), known by his ''Pen name, nom de plume'' Voltaire (, ; ), was a French Age of Enlightenment, Enlightenment writer, philosopher (''philosophe''), satirist, and historian. Famous for his wit ...
lampooned in his popular book ''
Candide ( , ) is a French satire written by Voltaire, a philosopher of the Age of Enlightenment, first published in 1759. The novella has been widely translated, with English versions titled ''Candide: or, All for the Best'' (1759); ''Candide: or, The ...
'', which concludes with the character Candide saying, "''
Non liquet In law, a ''non liquet'' (commonly known as " lacuna in the law") is any situation for which there is no applicable law. ''Non liquet'' translates into English from the Latin as "it is not clear". According to Cicero, the term was applied during ...
''" (it is not clear), a term that was applied during the Roman Republic to a legal verdict of "not proven". Voltaire's depiction of Leibniz's ideas was so influential that many believed it to be an accurate description. Thus Voltaire and his ''Candide'' bear some of the blame for the lingering failure to appreciate and understand Leibniz's ideas. Leibniz had an ardent disciple, Christian Wolff, whose dogmatic and facile outlook did Leibniz's reputation much harm. Leibniz also influenced
David Hume David Hume (; born David Home; – 25 August 1776) was a Scottish philosopher, historian, economist, and essayist who was best known for his highly influential system of empiricism, philosophical scepticism and metaphysical naturalism. Beg ...
, who read his ''
Théodicée (from French: ''Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil''), more simply known as , is a book of philosophy by the German polymath Gottfried Leibniz. The book, published in 1710, introduced the te ...
'' and used some of his ideas. In any event, philosophical fashion was moving away from the rationalism and system building of the 17th century, of which Leibniz had been such an ardent proponent. His work on law, diplomacy, and history was seen as of ephemeral interest. The vastness and richness of his correspondence went unrecognized. Leibniz's reputation began to recover with the 1765 publication of the ''Nouveaux Essais''. In 1768,
Louis Dutens Louis Dutens (15 January 173023 May 1812) was a French writer born in Tours, of Protestant parents, who lived most of his life in Britain or in British service on the continent. He went to London, where his uncle was a jeweller, and there obtai ...
edited the first multi-volume edition of Leibniz's writings, followed in the 19th century by a number of editions, including those edited by Erdmann, Foucher de Careil, Gerhardt, Gerland, Klopp, and Mollat. Publication of Leibniz's correspondence with notables such as
Antoine Arnauld Antoine Arnauld (; 6 February 16128 August 1694) was a French Catholic theologian, priest, philosopher and mathematician. He was one of the leading intellectuals of the Jansenist group of Port-Royal and had a very thorough knowledge of patr ...
,
Samuel Clarke Samuel Clarke (11 October 1675 – 17 May 1729) was an English philosopher and Anglican cleric. He is considered the major British figure in philosophy between John Locke and George Berkeley. Clarke's altered, Nontrinitarian revision of the 1 ...
,
Sophia of Hanover Sophia (born Princess Sophia of the Palatinate; – ) was Electress of Hanover from 19 December 1692 until 23 January 1698 as the consort of Prince-Elector Ernest Augustus. She was later the heiress presumptive to the thrones of England and ...
, and her daughter
Sophia Charlotte of Hanover Sophia Charlotte of Hanover (30 October 1668 – 1 February 1705) was the first Queen consort in Prussia as the wife of King Frederick I. She was the only daughter of Elector Ernest Augustus of Hanover and Sophia of the Palatinate. Her eldes ...
, began. In 1900,
Bertrand Russell Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British philosopher, logician, mathematician, and public intellectual. He had influence on mathematics, logic, set theory, and various areas of analytic ...
published a critical study of Leibniz's
metaphysics Metaphysics is the branch of philosophy that examines the basic structure of reality. It is traditionally seen as the study of mind-independent features of the world, but some theorists view it as an inquiry into the conceptual framework of ...
. Shortly thereafter,
Louis Couturat Louis Couturat (; 17 January 1868 – 3 August 1914) was a French logician, mathematician, philosopher, and linguist. Couturat was a pioneer of the constructed language Ido. Life and education Born in Paris. In 1887 he entered École Normale S ...
published an important study of Leibniz, and edited a volume of Leibniz's heretofore unpublished writings, mainly on logic. They made Leibniz somewhat respectable among 20th-century analytical and
linguistic Linguistics is the scientific study of language. The areas of linguistic analysis are syntax (rules governing the structure of sentences), semantics (meaning), Morphology (linguistics), morphology (structure of words), phonetics (speech sounds ...
philosophers in the English-speaking world (Leibniz had already been of great influence to many Germans such as
Bernhard Riemann Georg Friedrich Bernhard Riemann (; ; 17September 182620July 1866) was a German mathematician who made profound contributions to analysis, number theory, and differential geometry. In the field of real analysis, he is mostly known for the f ...
). For example, Leibniz's phrase ''
salva veritate In philosophy, salva veritate (or intersubstitutivity) is the logical condition by which two expressions may be interchanged without altering the truth-value of statements in which the expressions occur. Substitution ''salva veritate'' of co-extens ...
'', meaning interchangeability without loss of or compromising the truth, recurs in
Willard Quine Willard Van Orman Quine ( ; known to his friends as "Van"; June 25, 1908 – December 25, 2000) was an American philosopher and logician in the analytic tradition, recognized as "one of the most influential philosophers of the twentieth centur ...
's writings. Nevertheless, the secondary literature on Leibniz did not really blossom until after World War II. This is especially true of English speaking countries; in Gregory Brown's bibliography fewer than 30 of the English language entries were published before 1946. American Leibniz studies owe much to
Leroy Loemker Leroy E. Loemker (December 28, 1900 – November 28, 1985) was an American philosopher and historian of philosophy, best known for his scholarship on the works of Gottfried Wilhelm Leibniz. Over the course of his career, Loemker made significant ...
(1900–1985) through his translations and his interpretive essays in LeClerc (1973). Leibniz's philosophy was also highly regarded by Gilles Deleuze, who in 1988 published The Fold: Leibniz and the Baroque.
Nicholas Jolley Nicholas is a male name, the Anglophone version of an ancient Greek name in use since antiquity, and cognate with the modern Greek , . It originally derived from a combination of two Greek words meaning 'victory' and 'people'. In turn, the name ...
has surmised that Leibniz's reputation as a philosopher is now perhaps higher than at any time since he was alive. Analytic and contemporary philosophy continue to invoke his notions of
identity Identity may refer to: * Identity document * Identity (philosophy) * Identity (social science) * Identity (mathematics) Arts and entertainment Film and television * ''Identity'' (1987 film), an Iranian film * ''Identity'' (2003 film), an ...
,
individuation The principle of individuation, or ', describes the manner in which a thing is identified as distinct from other things. The concept appears in numerous fields and is encountered in works of Leibniz, Carl Jung, Gunther Anders, Gilbert Simondo ...
, and
possible worlds Possible Worlds may refer to: * Possible worlds, concept in philosophy * ''Possible Worlds'' (play), 1990 play by John Mighton ** ''Possible Worlds'' (film), 2000 film by Robert Lepage, based on the play * Possible Worlds (studio) * ''Possible ...
. Work in the history of 17th- and 18th-century
ideas In philosophy and in common usage, an idea (from the Greek word: ἰδέα (idea), meaning 'a form, or a pattern') is the results of thought. Also in philosophy, ideas can also be mental representational images of some object. Many philosophe ...
has revealed more clearly the 17th-century "Intellectual Revolution" that preceded the better-known Industrial and commercial revolutions of the 18th and 19th centuries. In Germany, various important institutions were named after Leibniz. In Hanover in particular, he is the namesake for some of the most important institutions in the town: * ''
Leibniz University Hannover Leibniz University Hannover (), also known as the University of Hannover, is a public university, public research university located in Hanover, Germany. Founded on 2 May 1831 as Higher Vocational School, the university has undergone six period ...
'' * ''Leibniz-Akademie'', Institution for academic and non-academic training and further education in the business sector * ''Gottfried Wilhelm Leibniz Bibliothek – Niedersächsische Landesbibliothek'', one of the largest regional and academic libraries in Germany and, alongside the Oldenburg State Library and the Herzog August Library in Wolfenbüttel, one of the three state libraries in Lower Saxony * ''Gottfried-Wilhelm-Leibniz-Gesellschaft'', Society for the cultivation and dissemination of Leibniz's teachings Outside of Hanover: * ''
Leibniz Association The Leibniz Association (German: ''Leibniz-Gemeinschaft'' or ''Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz'') is a union of German non-university research institutes from various disciplines. Funding and Structure As of 2020, 96 non-u ...
'', Berlin * ''Leibniz-Sozietät der Wissenschaften zu Berlin'', Association of scientists founded in Berlin in 1993 with the legal form of a registered association; It continues the activities of the Academy of Sciences of the GDR with personnel continuity * ''Leibniz Kolleg'' of
Tübingen University Tübingen (; ) is a traditional university city in central Baden-Württemberg, Germany. It is situated south of the state capital, Stuttgart, and developed on both sides of the Neckar and Ammer rivers. about one in three of the 90,000 people ...
, central propaedeutic institution of the university, which aims to enable high school graduates to make a well-founded study decision through a ten-month, comprehensive general course of study and at the same time to introduce them to academic work * Leibniz Supercomputing Centre, Munich * more than 20 schools all over Germany Awards: * ''Leibniz-Ring-Hannover'', Honor given since 1997 by the Hannover Press Club to personalities or institutions "who have drawn attention to themselves through an outstanding performance or have made a special mark through their life's work." * ''Leibniz-Medaille'' of the
Berlin-Brandenburg Academy of Sciences and Humanities The Berlin-Brandenburg Academy of Sciences and Humanities (), abbreviated BBAW, is the official academic society for the natural sciences and humanities for the German states of Berlin and Brandenburg. Housed in three locations in and around Ber ...
, established in 1906 and awarded previously by the
Prussian Academy of Sciences The Royal Prussian Academy of Sciences () was an academy established in Berlin, Germany on 11 July 1700, four years after the Prussian Academy of Arts, or "Arts Academy," to which "Berlin Academy" may also refer. In the 18th century, when Frenc ...
and later the
German Academy of Sciences at Berlin The German Academy of Sciences at Berlin, , in 1972 renamed the Academy of Sciences of the GDR (''Akademie der Wissenschaften der DDR (AdW)''), was the most eminent Research institute, research institution of East Germany (German Democratic Repub ...
* ''Gottfried-Wilhelm-Leibniz-Medaille'' of the Leibniz-Sozietät * ''Leibniz-Medaille der Akademie der Wissenschaften und der Literatur Mainz'' In 1985, the German government created the Leibniz Prize, offering an annual award of 1.55 million
euro The euro (currency symbol, symbol: euro sign, €; ISO 4217, currency code: EUR) is the official currency of 20 of the Member state of the European Union, member states of the European Union. This group of states is officially known as the ...
s for experimental results and 770,000 euros for theoretical ones. It was the world's largest prize for scientific achievement prior to the
Fundamental Physics Prize The Breakthrough Prize in Fundamental Physics is one of the Breakthrough Prizes, awarded by the Breakthrough Prize Board. Initially named Fundamental Physics Prize, it was founded in July 2012 by Russia-born Israeli entrepreneur, venture capit ...
. The collection of manuscript papers of Leibniz at the Gottfried Wilhelm Leibniz Bibliothek – Niedersächische Landesbibliothek was inscribed on
UNESCO The United Nations Educational, Scientific and Cultural Organization (UNESCO ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) with the aim of promoting world peace and International secur ...
's
Memory of the World Register UNESCO's Memory of the World (MoW) Programme is an international initiative to safeguard the documentary heritage of humanity against collective amnesia, neglect, decay over time and climatic conditions, as well as deliberate destruction. It ca ...
in 2007.


Cultural references

Leibniz still receives popular attention. The
Google Doodle Google Doodle is a special, temporary alteration of the logo on Google's homepages intended to commemorate holidays, events, achievements, and historical figures. The first Google Doodle honored the 1998 edition of the long-running annual Bu ...
for 1 July 2018 celebrated Leibniz's 372nd birthday. Using a
quill A quill is a writing tool made from a moulted flight feather (preferably a primary wing-feather) of a large bird. Quills were used for writing with ink before the invention of the dip pen/metal-Nib (pen), nibbed pen, the fountain pen, and, event ...
, his hand is shown writing "Google" in binary
ASCII ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...
code. One of the earliest popular but indirect expositions of Leibniz was
Voltaire François-Marie Arouet (; 21 November 169430 May 1778), known by his ''Pen name, nom de plume'' Voltaire (, ; ), was a French Age of Enlightenment, Enlightenment writer, philosopher (''philosophe''), satirist, and historian. Famous for his wit ...
's satire ''
Candide ( , ) is a French satire written by Voltaire, a philosopher of the Age of Enlightenment, first published in 1759. The novella has been widely translated, with English versions titled ''Candide: or, All for the Best'' (1759); ''Candide: or, The ...
'', published in 1759. Leibniz was lampooned as Professor Pangloss, described as "the greatest philosopher of the
Holy Roman Empire The Holy Roman Empire, also known as the Holy Roman Empire of the German Nation after 1512, was a polity in Central and Western Europe, usually headed by the Holy Roman Emperor. It developed in the Early Middle Ages, and lasted for a millennium ...
". Leibniz also appears as one of the main historical figures in
Neal Stephenson Neal Town Stephenson (born October 31, 1959) is an American writer known for his works of speculative fiction. His novels have been categorized as science fiction, historical fiction, cyberpunk, and baroque. Stephenson's work explores mathemati ...
's series of novels ''
The Baroque Cycle ''The Baroque Cycle'' is a series of novels by American writer Neal Stephenson. It was published in three volumes containing eight books in 2003 and 2004. The story follows the adventures of a sizable cast of characters living amidst some of th ...
''. Stephenson credits readings and discussions concerning Leibniz for inspiring him to write the series.Stephenson, Neal. "How the Baroque Cycle Began" in P.S. of '' Quicksilver'' Perennial ed. 2004. Leibniz also stars in Adam Ehrlich Sachs's novel ''The Organs of Sense''. The German biscuit Choco Leibniz is named after Leibniz, a famous resident of
Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...
where the manufacturer
Bahlsen Bahlsen GmbH & Co. KG is a German food company based in Hanover. It was founded in July 1889 by Hermann Bahlsen (1859–1919) as the "Hannoversche Cakesfabrik H. Bahlsen". Bahlsen makes products such as chocolate-dipped Pick Up! snack bars. B ...
is based.


Writings and publication

Leibniz mainly wrote in three languages: scholastic
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
, French and German. During his lifetime, he published many pamphlets and scholarly articles, but only two "philosophical" books, the ''Combinatorial Art'' and the ''
Théodicée (from French: ''Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil''), more simply known as , is a book of philosophy by the German polymath Gottfried Leibniz. The book, published in 1710, introduced the te ...
''. (He published numerous pamphlets, often anonymous, on behalf of the House of Brunswick-Lüneburg, most notably the "De jure suprematum" a major consideration of the nature of
sovereignty Sovereignty can generally be defined as supreme authority. Sovereignty entails hierarchy within a state as well as external autonomy for states. In any state, sovereignty is assigned to the person, body or institution that has the ultimate au ...
.) One substantial book appeared posthumously, his ''
Nouveaux essais sur l'entendement humain ''New Essays on Human Understanding'' () is a chapter-by-chapter rebuttal by Gottfried Leibniz of John Locke's major work ''An Essay Concerning Human Understanding'' (1689). It is one of only two full-length works by Leibniz (the other being the ...
'', which Leibniz had withheld from publication after the death of
John Locke John Locke (; 29 August 1632 (Old Style and New Style dates, O.S.) – 28 October 1704 (Old Style and New Style dates, O.S.)) was an English philosopher and physician, widely regarded as one of the most influential of the Enlightenment thi ...
. Only in 1895, when Bodemann completed his catalogue of Leibniz's manuscripts and correspondence, did the enormous extent of Leibniz's ''
Nachlass ''Nachlass'' (, older spelling ''Nachlaß'') is a German language, German word, used in academia to describe the collection of manuscripts, notes, correspondence, and so on left behind when a scholar dies. The word is a compound word, compound in ...
'' become clear: about 15,000 letters to more than 1000 recipients plus more than 40,000 other items. Moreover, quite a few of these letters are of essay length. Much of his vast correspondence, especially the letters dated after 1700, remains unpublished, and much of what is published has appeared only in recent decades. The more than 67,000 records of th
Leibniz Edition's Catalogue
cover almost all of his known writings and the letters from him and to him. The amount, variety, and disorder of Leibniz's writings are a predictable result of a situation he described in a letter as follows: The extant parts of the critical edition of Leibniz's writings are organized as follows: * Series 1. ''Political, Historical, and General Correspondence''. 25 vols., 1666–1706. * Series 2. ''Philosophical Correspondence''. 3 vols., 1663–1700. * Series 3. ''Mathematical, Scientific, and Technical Correspondence''. 8 vols., 1672–1698. * Series 4.
Political Writings
'. 9 vols., 1667–1702. * Series 5.
Historical and Linguistic Writings
'. In preparation. * Series 6. ''Philosophical Writings''. 7 vols., 1663–1690, and ''Nouveaux essais sur l'entendement humain''. * Series 7. ''Mathematical Writings''. 6 vols., 1672–1676. * Series 8. ''Scientific, Medical, and Technical Writings''. 1 vol., 1668–1676. The systematic cataloguing of all of Leibniz's ''Nachlass'' began in 1901. It was hampered by two world wars and then by decades of German division into two states, separating scholars and scattering portions of his literary estates. The ambitious project has had to deal with writings in seven languages, contained in some 200,000 written and printed pages. In 1985 it was reorganized and included in a joint program of German federal and state (''Länder'') academies. Since then the branches in
Potsdam Potsdam () is the capital and largest city of the Germany, German States of Germany, state of Brandenburg. It is part of the Berlin/Brandenburg Metropolitan Region. Potsdam sits on the Havel, River Havel, a tributary of the Elbe, downstream of B ...
,
Münster Münster (; ) is an independent city#Germany, independent city (''Kreisfreie Stadt'') in North Rhine-Westphalia, Germany. It is in the northern part of the state and is considered to be the cultural centre of the Westphalia region. It is also a ...
,
Hanover Hanover ( ; ; ) is the capital and largest city of the States of Germany, German state of Lower Saxony. Its population of 535,932 (2021) makes it the List of cities in Germany by population, 13th-largest city in Germany as well as the fourth-l ...
and Berlin have jointly published 57 volumes of the critical edition, with an average of 870 pages, and prepared index and concordance works.


Selected works

The year given is usually that in which the work was completed, not of its eventual publication. * 1666 (publ. 1690). ''
De Arte Combinatoria The ''Dissertatio de arte combinatoria'' ("Dissertation on the Art of Combinations" or "On the Combinatorial Art") is an early work by Gottfried Leibniz published in 1666 in Leipzig. It is an extended version of his first doctoral dissertation, wr ...
'' (''On the Art of Combination''); partially translated in Loemker §1 and Parkinson (1966) * 1667. ''Nova Methodus Discendae Docendaeque Iurisprudentiae'' (''A New Method for Learning and Teaching Jurisprudence'') * 1667. "Dialogus de connexione inter res et verba" * 1671. ''Hypothesis Physica Nova'' (''New Physical Hypothesis''); Loemker §8.I (part) * 1673 '' Confessio philosophi'' (''A Philosopher's Creed''); an English translation is
available In reliability engineering, the term availability has the following meanings: * The degree to which a system, subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at a ...
online. * Oct. 1684. "Meditationes de cognitione, veritate et ideis" ("Meditations on Knowledge, Truth, and Ideas") * Nov. 1684. "
Nova methodus pro maximis et minimis "Nova Methodus pro Maximis et Minimis" is the first published work on the subject of calculus. It was published by Gottfried Leibniz in the ''Acta Eruditorum'' in October 1684. It is considered to be the birth of infinitesimal calculus. Full tit ...
" ("New method for maximums and minimums"); translated in Struik, D. J., 1969. ''A Source Book in Mathematics, 1200–1800''. Harvard University Press: 271–81. * 1686. '' Discours de métaphysique''; Martin and Brown (1988), Ariew and Garber 35, Loemker §35, Wiener III.3, Woolhouse and Francks 1 * 1686. ''Generales inquisitiones de analysi notionum et veritatum'' (''General Inquiries About the Analysis of Concepts and of Truths'') * 1694. "De primae philosophiae Emendatione, et de Notione Substantiae" ("On the Correction of First Philosophy and the Notion of Substance") * 1695. ''Système nouveau de la nature et de la communication des substances'' (''New System of Nature'') * 1700. ''Accessiones historicae''. * 1703. "Explication de l'Arithmétique Binaire" ("Explanation of Binary Arithmetic"); Carl Immanuel Gerhardt, ''Mathematical Writings'' VII.223. An English translation by
Lloyd Strickland Lloyd Strickland (born 1973) is a British philosopher, intellectual historian, Leibniz scholar, and translator of early modern philosophical texts. He is Professor of Philosophy and Intellectual History at Manchester Metropolitan University. Re ...
i
available
online. * 1704 (publ. 1765). ''
Nouveaux essais sur l'entendement humain ''New Essays on Human Understanding'' () is a chapter-by-chapter rebuttal by Gottfried Leibniz of John Locke's major work ''An Essay Concerning Human Understanding'' (1689). It is one of only two full-length works by Leibniz (the other being the ...
''. Translated in: Remnant, Peter, and Bennett, Jonathan, trans., 1996. ''New Essays on Human Understanding'' Langley translation 1896. Cambridge University Press. Wiener III.6 (part) * 1707–1710. ''Scriptores rerum Brunsvicensium'' (3 Vols.) * 1710. ''
Théodicée (from French: ''Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil''), more simply known as , is a book of philosophy by the German polymath Gottfried Leibniz. The book, published in 1710, introduced the te ...
''; Farrer, A. M., and Huggard, E. M., trans., 1985 (1952). Wiener III.11 (part). An English translation i
available
online at
Project Gutenberg Project Gutenberg (PG) is a volunteer effort to digitize and archive cultural works, as well as to "encourage the creation and distribution of eBooks." It was founded in 1971 by American writer Michael S. Hart and is the oldest digital li ...
. * 1714. "Principes de la nature et de la Grâce fondés en raison" * 1714. ''
Monadologie The ''Monadology'' (, 1714) is one of Gottfried Leibniz's best known works of his later philosophy. It is a short text which presents, in some 90 paragraphs, a metaphysics of simple substance theory, substances, or ''monad (philosophy), monads'' ...
''; translated by
Nicholas Rescher Nicholas Rescher (; ; 15 July 1928 – 5 January 2024) was a German-born American philosopher, polymath, and author, who was a professor of philosophy at the University of Pittsburgh from 1961. He was chairman of the Center for Philosophy of Sc ...
, 1991. ''The Monadology: An Edition for Students''. University of Pittsburgh Press. Ariew and Garber 213, Loemker §67, Wiener III.13, Woolhouse and Francks 19. An English translation by Robert Latta i
available
online.


Posthumous works

* 1717. ''Collectanea Etymologica'', edited by the secretary of Leibniz
Johann Georg von Eckhart Johann Georg von Eckhart (7 September 1664 – 9 February 1730) was a German historian and linguist. Biography Eckhart was born at Duingen in the Principality of Calenberg. After preparatory training at Schulpforta, he went to Leipzig, where a ...
* 1749. ''
Protogaea ''Protogaea'' is a work by Gottfried Leibniz on geology and natural history. Unpublished in his lifetime, but made known by Johann Georg von Eckhart in 1719, it was conceived as a preface to his incomplete history of the House of Brunswick. Lif ...
'' * 1750. ''Origines Guelficae''


Collections

Six important collections of English translations are Wiener (1951), Parkinson (1966), Loemker (1969), Ariew and Garber (1989), Woolhouse and Francks (1998), and Strickland (2006). The ongoing critical edition of all of Leibniz's writings is ''Sämtliche Schriften und Briefe''.


See also

*
General Leibniz rule In calculus, the general Leibniz rule, named after Gottfried Wilhelm Leibniz, generalizes the product rule for the derivative of the product of two (which is also known as "Leibniz's rule"). It states that if f and g are -times differentiable fu ...
*
Leibniz Association The Leibniz Association (German: ''Leibniz-Gemeinschaft'' or ''Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz'') is a union of German non-university research institutes from various disciplines. Funding and Structure As of 2020, 96 non-u ...
*
Leibniz operator In abstract algebraic logic, a branch of mathematical logic, the Leibniz operator is a tool used to classify deductive systems, which have a precise technical definition and capture a large number of logics. The Leibniz operator was introduced by Wi ...
*
List of German inventors and discoverers This is a list of German inventors and discoverers. The following list comprises people from Germany or German-speaking Europe, and also people of predominantly German heritage, in alphabetical order of the surname. A *Ernst Abbe: Invented th ...
*
List of pioneers in computer science This is a list of people who made transformative breakthroughs in the creation, development and imagining of what computers could do. Pioneers ~ Items marked with a tilde are circa dates. See also * Computer Pioneer Award * IEEE John von ...
*
List of things named after Gottfried Leibniz Gottfried Wilhelm Leibniz (1646–1716) was a German philosopher and mathematician. In engineering, the following concepts are attributed to Leibniz: * Leibniz wheel, a cylinder used in a class of mechanical calculators * Leibniz calculator, a ...
* ''
Mathesis universalis (from , "science or learning", and "universal") is a hypothetical universal science modelled on mathematics envisaged by René Descartes, Descartes and Gottfried Wilhelm Leibniz, Leibniz, among a number of other 16th- and 17th-century philosop ...
'' *
Scientific Revolution The Scientific Revolution was a series of events that marked the emergence of History of science, modern science during the early modern period, when developments in History of mathematics#Mathematics during the Scientific Revolution, mathemati ...
*
Leibniz University Hannover Leibniz University Hannover (), also known as the University of Hannover, is a public university, public research university located in Hanover, Germany. Founded on 2 May 1831 as Higher Vocational School, the university has undergone six period ...
*
Bartholomew Des Bosses Bartholomew Des Bosses (29 August 1668, Chaineux; 17 April 1738, Cologne) was a Jesuit theologian and philosopher, known mainly for his voluminous correspondence with Leibniz. Biography Des Bosses joined the Society of Jesus in 1686. In 1700, ...
*
Joachim Bouvet Joachim Bouvet (, courtesy name: 明远) (July 18, 1656, in Le Mans – June 28, 1730, in Peking) was a French Jesuit who worked in China, and the leading member of the Figurist movement. China Bouvet was born in Le Mans, France; he entered th ...
*
Outline of Gottfried Wilhelm Leibniz The following Outline (list), outline is provided as an overview of and topical guide to Gottfried Wilhelm Leibniz: Gottfried Wilhelm Leibniz, Gottfried Wilhelm (von) Leibniz (1 July 1646 .S. 21 June– 14 November 1716); German polymath, phi ...
*
Gottfried Wilhelm Leibniz bibliography Gottfried Wilhelm Leibniz was a major contributor to mathematics, physics, philosophy, theology, logic, and early computer science; independent inventor of calculus in mathematics; inventor of energy and the action principle in physics; jurist, gene ...


Notes


References


Citations


Sources


Bibliographies

* Bodemann, Eduard, ''Die Leibniz-Handschriften der Königlichen öffentlichen Bibliothek zu Hannover'', 1895, (anastatic reprint: Hildesheim, Georg Olms, 1966). * Bodemann, Eduard, ''Der Briefwechsel des Gottfried Wilhelm Leibniz in der Königlichen öffentlichen Bibliothek zu Hannover'', 1889, (anastatic reprint: Hildesheim, Georg Olms, 1966). * Ravier, Émile, ''Bibliographie des œuvres de Leibniz'', Paris: Alcan, 1937 (anastatic reprint Hildesheim: Georg Olms, 1966). * Heinekamp, Albert and Mertens, Marlen. ''Leibniz-Bibliographie. Die Literatur über Leibniz bis 1980'', Frankfurt: Vittorio Klostermann, 1984. * Heinekamp, Albert and Mertens, Marlen. ''Leibniz-Bibliographie. Die Literatur über Leibniz. Band II: 1981–1990'', Frankfurt: Vittorio Klostermann, 1996. An updated bibliography of more than 25.000 titles is available a
Leibniz Bibliographie


Primary literature (chronologically)

* Wiener, Philip, (ed.), 1951. ''Leibniz: Selections''. Scribner. * Schrecker, Paul & Schrecker, Anne Martin, (eds.), 1965. ''Monadology and other Philosophical Essays''. Prentice-Hall. * Parkinson, G. H. R. (ed.), 1966. ''Logical Papers''. Clarendon Press. * Mason, H. T. & Parkinson, G. H. R. (eds.), 1967. ''The Leibniz-Arnauld Correspondence''. Manchester University Press. * Loemker, Leroy, (ed.), 1969
956 Year 956 ( CMLVI) was a leap year starting on Tuesday of the Julian calendar. Events By place Byzantine Empire * Summer – Emperor Constantine VII appoints Nikephoros Phokas to commander of the Byzantine field army (''Domestic o ...
''Leibniz: Philosophical Papers and Letters''. Reidel. * Morris, Mary & Parkinson, G. H. R. (eds.), 1973. ''Philosophical Writings''. Everyman's University Library. * Riley, Patrick, (ed.), 1988. ''Leibniz: Political Writings''. Cambridge University Press. * Niall, R. Martin, D. & Brown, Stuart (eds.), 1988. ''Discourse on Metaphysics and Related Writings''. Manchester University Press. * Ariew, Roger and Garber, Daniel. (eds.), 1989. ''Leibniz: Philosophical Essays''. Hackett. * Rescher, Nicholas (ed.), 1991. ''G. W. Leibniz's Monadology. An Edition for Students'', University of Pittsburgh Press. * Rescher, Nicholas, ''On Leibniz'', (Pittsburgh: University of Pittsburgh Press, 2013). * Parkinson, G. H. R. (ed.) 1992. ''De Summa Rerum. Metaphysical Papers, 1675–1676''. Yale University Press. * Cook, Daniel, & Rosemont, Henry Jr., (eds.), 1994. ''Leibniz: Writings on China''. Open Court. * Farrer, Austin (ed.), 1995. ''Theodicy'', Open Court. * Remnant, Peter, & Bennett, Jonathan, (eds.), 1996 (1981). ''Leibniz: New Essays on Human Understanding''. Cambridge University Press. * Woolhouse, R. S., and Francks, R., (eds.), 1997. ''Leibniz's 'New System' and Associated Contemporary Texts''. Oxford University Press. * Woolhouse, R. S., and Francks, R., (eds.), 1998. ''Leibniz: Philosophical Texts''. Oxford University Press. * Ariew, Roger, (ed.), 2000. ''G. W. Leibniz and Samuel Clarke: Correspondence''. Hackett. * Richard T. W. Arthur, (ed.), 2001. ''The Labyrinth of the Continuum: Writings on the Continuum Problem, 1672–1686''. Yale University Press. * Richard T. W. Arthur, 2014. ''Leibniz''. John Wiley & Sons. * Robert C. Sleigh Jr., (ed.), 2005. ''Confessio Philosophi: Papers Concerning the Problem of Evil, 1671–1678''. Yale University Press. * Dascal, Marcelo (ed.), 2006. ''G. W. Leibniz. The Art of Controversies'', Springer. * Strickland, Lloyd, 2006 (ed.). ''The Shorter Leibniz Texts: A Collection of New Translations''. Continuum. * Look, Brandon and Rutherford, Donald (eds.), 2007. ''The Leibniz-Des Bosses Correspondence'', Yale University Press. * Cohen, Claudine and Wakefield, Andre, (eds.), 2008. ''Protogaea''. University of Chicago Press. * Murray, Michael, (ed.) 2011. ''Dissertation on Predestination and Grace'', Yale University Press. * Strickand, Lloyd (ed.), 2011. ''Leibniz and the two Sophies. The Philosophical Correspondence'', Toronto. * Lodge, Paul (ed.), 2013. ''The Leibniz-De Volder Correspondence: With Selections from the Correspondence Between Leibniz and Johann Bernoulli'', Yale University Press. * Artosi, Alberto, Pieri, Bernardo, Sartor, Giovanni (eds.), 2014. ''Leibniz: Logico-Philosophical Puzzles in the Law'', Springer. * De Iuliis, Carmelo Massimo, (ed.), 2017. ''Leibniz: The New Method of Learning and Teaching Jurisprudence'', Talbot, Clark NJ.


Secondary literature up to 1950

* Du Bois-Reymond, Emil, 1912. ''Leibnizsche Gedanken in der neueren Naturwissenschaft'', Berlin: Dummler, 1871 (reprinted in ''Reden'', Leipzig: Veit, vol. 1). * Couturat, Louis, 1901. ''La Logique de Leibniz''. Paris: Felix Alcan. * Heidegger, Martin, 1983. ''The Metaphysical Foundations of Logic''. Indiana University Press (lecture course, 1928). * Lovejoy, Arthur O., 1957 (1936). "Plenitude and Sufficient Reason in Leibniz and Spinoza" in his ''The Great Chain of Being''. Harvard University Press: 144–182. Reprinted in Frankfurt, H. G., (ed.), 1972. ''Leibniz: A Collection of Critical Essays''. Anchor Books 1972. * Mackie, John Milton; Guhrauer, Gottschalk Eduard, 1845. ''Life of Godfrey William von ''. Gould, Kendall and Lincoln. * Russell, Bertrand, 1900, ''A Critical Exposition of the Philosophy of Leibniz'', Cambridge: The University Press. * * Trendelenburg, F. A., 1857, "Über Leibnizens Entwurf einer allgemeinen Charakteristik," ''Philosophische Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin. Aus dem Jahr 1856'', Berlin: Commission Dümmler, pp. 36–69. * (lecture)


Secondary literature post-1950

* Adams, Robert Merrihew. 1994. ''Leibniz: Determinist, Theist, Idealist''. New York: Oxford, Oxford University Press. * Aiton, Eric J., 1985. ''Leibniz: A Biography''. Hilger (UK). * Antognazza, Maria Rosa, 2008. ''Leibniz: An Intellectual Biography''. Cambridge University Press. * Antognazza, Maria Rosa, 2016. ''Leibniz: A Very Short Introduction''. Oxford University Press. * Antognazza, Maria Rosa, ed., 2018. ''Oxford Handbook of Leibniz''. Oxford University Press. * * Borowski, Audrey, 2024
''Leibniz in His World: The Making of a Savant''
Princeton University Press. * * Brown, Stuart (ed.), 1999. ''The Young Leibniz and His Philosophy (1646–76)'', Dordrecht, Kluwer. * Connelly, Stephen, 2021. ''Leibniz: A Contribution to the Archaeology of Power'', Edinburgh University Press . * Davis, Martin, 2000. ''The Universal Computer: The Road from Leibniz to Turing''. WW Norton. * Deleuze, Gilles, 1993. ''The Fold: Leibniz and the Baroque''. University of Minnesota Press. * Fahrenberg, Jochen, 2017. PsyDok ZPI
The influence of Gottfried Wilhelm Leibniz on the Psychology, Philosophy, and Ethics of Wilhelm Wundt.
* Fahrenberg, Jochen, 2020. ''Wilhelm Wundt (1832–1920). Introduction, Quotations, Reception, Commentaries, Attempts at Reconstruction''. Pabst Science Publishers, Lengerich 2020, . * Finster, Reinhard & van den Heuvel, Gerd 2000. ''Gottfried Wilhelm Leibniz''. Mit Selbstzeugnissen und Bilddokumenten. 4. Auflage. Rowohlt, Reinbek bei Hamburg (Rowohlts Monographien, 50481), . * Grattan-Guinness, Ivor, 1997. ''The Norton History of the Mathematical Sciences''. W W Norton. * Hall, A. R., 1980. ''Philosophers at War: The Quarrel between Newton and Leibniz''. Cambridge University Press. * Hamza, Gabor, 2005. "Le développement du droit privé européen". ELTE Eotvos Kiado Budapest. * * Hostler, John, 1975. ''Leibniz's Moral Philosophy''. UK: Duckworth. * Ishiguro, Hidé 1990. ''Leibniz's Philosophy of Logic and Language''. Cambridge University Press. * Jolley, Nicholas, (ed.), 1995. ''The Cambridge Companion to Leibniz''. Cambridge University Press. * Kaldis, Byron, 2011. "Leibniz' Argument for Innate Ideas", in Bruce, Michael and Barbone, Steven, eds., ''Just the Arguments: 100 of the Most Important Arguments in Western Philosophy''. Wiley-Blackwell. * * Kempe, Michael, 2024. ''The Best of All Possible Worlds: A Life of Leibniz in Seven Pivotal Days''. W. W. Norton. *Kromer, Ralf, and Yannick Chin-Drian. ''New Essays on Leibniz Reception: In Science and Philosophy of Science 1800-2000.'' 1st ed. 2012. Heidelberg: Birkhauser, 2012. * LeClerc, Ivor (ed.), 1973. ''The Philosophy of Leibniz and the Modern World''. Vanderbilt University Press. * * Mates, Benson, 1986. ''The Philosophy of Leibniz: Metaphysics and Language''. Oxford University Press. * Mercer, Christia, 2001. ''Leibniz's Metaphysics: Its Origins and Development''. Cambridge University Press. * Perkins, Franklin, 2004. ''Leibniz and China: A Commerce of Light''. Cambridge University Press. * Riley, Patrick, 1996. ''Leibniz's Universal Jurisprudence: Justice as the Charity of the Wise''. Harvard University Press. * Rutherford, Donald, 1998. ''
Leibniz and the Rational Order of Nature ''Leibniz and the Rational Order of Nature'' is a 1995 book about the concept of order in Leibniz's thought by Donald Rutherford. Reception John Whipple from University of Illinois at Chicago calls the book "one of the most important books ab ...
''. Cambridge University Press. * Schulte-Albert, H. G. (1971). Gottfried Wilhelm Leibniz and Library Classification. ''The Journal of Library History'' (1966–1972), (2). 133–152. * * Smith, Justin E. H., 2011. ''Divine Machines. Leibniz and the Sciences of Life'', Princeton University Press. * Wilson, Catherine, 1989. ''Leibniz's Metaphysics: A Historical and Comparative Study''.
Princeton University Press Princeton University Press is an independent publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large. The press was founded by Whitney Darrow, with the financial ...
. *


External links

* * * * * * * Horn, Joshua. * Jorarti, Julia. * * *
Translations
by Jonathan Bennett, of the ''New Essays'', the exchanges with Bayle, Arnauld and Clarke, and about 15 shorter works.
Gottfried Wilhelm Leibniz: Texts and Translations
compiled by Donald Rutherford,
UCSD The University of California, San Diego (UC San Diego in communications material, formerly and colloquially UCSD) is a public land-grant research university in San Diego, California, United States. Established in 1960 near the pre-existing ...

Leibnitiana
links and resources edited by Gregory Brown,
University of Houston The University of Houston (; ) is a Public university, public research university in Houston, Texas, United States. It was established in 1927 as Houston Junior College, a coeducational institution and one of multiple junior colleges formed in ...

Philosophical Works of Leibniz translated by G.M. Duncan (1890)

The Best of All Possible Worlds: Nicholas Rescher Talks About Gottfried Wilhelm von Leibniz's "Versatility and Creativity"

"Protogæa"
(1693, Latin, in ''Acta eruditorum'') –
Linda Hall Library The Linda Hall Library is a privately endowed American library of science, engineering and technology located in Kansas City, Missouri, on the grounds of a urban arboretum. It claims to be the "largest independently funded public library of sc ...

''Protogaea''
(1749, German) – full digital facsimile from
Linda Hall Library The Linda Hall Library is a privately endowed American library of science, engineering and technology located in Kansas City, Missouri, on the grounds of a urban arboretum. It claims to be the "largest independently funded public library of sc ...
* Leibniz's (1768, 6-volume
''Opera omnia''
– digital facsimile * Leibniz's arithmetical machine, 1710, online and analyzed on
BibNum
''
lick 'à télécharger' for English analysis Lick may refer to: * Licking, the action of passing the tongue over a surface Places * Lick (crater), a crater on the Moon named after James Lick * 1951 Lick, an asteroid named after James Lick * Lick Township, Jackson County, Ohio, United St ...
/small> * Leibniz's binary numeral system, 'De progressione dyadica', 1679, online and analyzed on
BibNum
''
lick 'à télécharger' for English analysis Lick may refer to: * Licking, the action of passing the tongue over a surface Places * Lick (crater), a crater on the Moon named after James Lick * 1951 Lick, an asteroid named after James Lick * Lick Township, Jackson County, Ohio, United St ...
/small> {{DEFAULTSORT:Leibniz, Gottfried 1646 births 1716 deaths 17th-century German mathematicians 17th-century German philosophers 17th-century German scientists 17th-century German writers 17th-century German male writers 17th-century writers in Latin 17th-century German inventors 18th-century German mathematicians 18th-century German philosophers 18th-century German physicists 18th-century German scientists 18th-century German writers 18th-century German male writers 18th-century writers in Latin 18th-century German inventors Constructed language creators Determinists Enlightenment philosophers Fellows of the Royal Society German librarians German logicians German Lutherans German philologists German political philosophers German Protestants German writers in French Leipzig University alumni German mathematical analysts Mathematics of infinitesimals Linear algebraists Members of the Prussian Academy of Sciences Panpsychism People associated with Baruch Spinoza People educated at the St. Thomas School, Leipzig People from the Electorate of Saxony People of the Age of Enlightenment German philosophers of language German philosophers of law Philosophers of logic German philosophers of mind Philosophical theists German philosophy writers Rationalists University of Altdorf alumni Writers from Leipzig Writers about religion and science Critics of atheism