The Vienna Circle () of
logical empiricism was a group of elite
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 ...
s and
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 ...
s drawn from the
natural and
social sciences
Social science (often rendered in the plural as the social sciences) is one of the branches of science, devoted to the study of society, societies and the Social relation, relationships among members within those societies. The term was former ...
,
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
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 ...
who met regularly from 1924 to 1936 at the
University of Vienna
The University of Vienna (, ) is a public university, public research university in Vienna, Austria. Founded by Rudolf IV, Duke of Austria, Duke Rudolph IV in 1365, it is the oldest university in the German-speaking world and among the largest ...
, chaired by
Moritz Schlick. The Vienna Circle had a profound influence on
20th-century philosophy
Contemporary philosophy is the present period in the history of Western philosophy beginning at the early 20th century with the increasing professionalization of the discipline and the rise of Analytic philosophy, analytic and continental philosop ...
, especially
philosophy of science
Philosophy of science is the branch of philosophy concerned with the foundations, methods, and implications of science. Amongst its central questions are the difference between science and non-science, the reliability of scientific theories, ...
and
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 ...
.
The philosophical position of the Vienna Circle was called logical empiricism (German: ''logischer Empirismus''),
logical positivism or
neopositivism. It was influenced by
Ernst Mach,
David Hilbert
David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician and philosopher of mathematics and one of the most influential mathematicians of his time.
Hilbert discovered and developed a broad range of fundamental idea ...
, French
conventionalism (
Henri Poincaré
Jules Henri Poincaré (, ; ; 29 April 185417 July 1912) was a French mathematician, Theoretical physics, theoretical physicist, engineer, and philosophy of science, philosopher of science. He is often described as a polymath, and in mathemati ...
and
Pierre Duhem
Pierre Maurice Marie Duhem (; 9 June 1861 – 14 September 1916) was a French theoretical physicist who made significant contributions to thermodynamics, hydrodynamics, and the theory of Elasticity (physics), elasticity. Duhem was also a prolif ...
),
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 ...
,
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 ...
,
Ludwig Wittgenstein
Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.
From 1929 to 1947, Witt ...
and
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 ...
. The Vienna Circle was pluralistic and committed to the ideals of the
Enlightenment. It was unified by the aim of making philosophy scientific with the help of 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 ...
. Main topics were foundational debates in the natural and social sciences, logic and mathematics; the modernization of
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 ...
by modern logic; the search for an empiricist criterion of meaning; the critique of
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 ...
and the unification of the sciences in the
unity of science.
The Vienna Circle appeared in public with the publication of various book series – ''Schriften zur wissenschaftlichen Weltauffassung'' (''Monographs on the Scientific World-Conception''), ''Einheitswissenschaft'' (''Unified Science'') and the journal ''
Erkenntnis'' – and the organization of international conferences in
Prague
Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...
;
Königsberg
Königsberg (; ; ; ; ; ; , ) is the historic Germany, German and Prussian name of the city now called Kaliningrad, Russia. The city was founded in 1255 on the site of the small Old Prussians, Old Prussian settlement ''Twangste'' by the Teuton ...
(today known as
Kaliningrad);
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
;
Copenhagen
Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...
;
Cambridge
Cambridge ( ) is a List of cities in the United Kingdom, city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, north of London. As of the 2021 Unit ...
, UK, and
Cambridge, Massachusetts
Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, ...
. Its public profile was provided by the ''Ernst Mach Society'' (German: ''Verein Ernst Mach'') through which members of the Vienna Circle sought to popularize their ideas in the context of programmes for popular education in Vienna.
During the era of
Austrofascism and after the
annexation of Austria by
Nazi Germany
Nazi Germany, officially known as the German Reich and later the Greater German Reich, was the German Reich, German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a Totalit ...
most members of the Vienna Circle were forced to emigrate. The murder of Schlick in 1936 by former student
Johann Nelböck put an end to the Vienna Circle in Austria.
History
The history and development of the Vienna Circle shows various stages:
First Vienna Circle (1907–1912)
The pre-history of the Vienna Circle began with meetings on the
philosophy of science
Philosophy of science is the branch of philosophy concerned with the foundations, methods, and implications of science. Amongst its central questions are the difference between science and non-science, the reliability of scientific theories, ...
and
epistemology
Epistemology is the branch of philosophy that examines the nature, origin, and limits of knowledge. Also called "the theory of knowledge", it explores different types of knowledge, such as propositional knowledge about facts, practical knowle ...
from 1908 on, promoted by
Philipp Frank,
Hans Hahn and
Otto Neurath.
Hans Hahn, the oldest of the three (1879–1934), was a mathematician. He received his degree in
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 ...
in 1902. Afterwards he studied under the direction of
Ludwig Boltzmann
Ludwig Eduard Boltzmann ( ; ; 20 February 1844 – 5 September 1906) was an Austrian mathematician and Theoretical physics, theoretical physicist. His greatest achievements were the development of statistical mechanics and the statistical ex ...
in Vienna and
David Hilbert
David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician and philosopher of mathematics and one of the most influential mathematicians of his time.
Hilbert discovered and developed a broad range of fundamental idea ...
,
Felix Klein
Felix Christian Klein (; ; 25 April 1849 – 22 June 1925) was a German mathematician and Mathematics education, mathematics educator, known for his work in group theory, complex analysis, non-Euclidean geometry, and the associations betwe ...
and
Hermann Minkowski in
Göttingen
Göttingen (, ; ; ) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. According to the 2022 German census, t ...
. In 1905 he received the
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 ...
in mathematics. He taught at
Innsbruck
Innsbruck (; ) is the capital of Tyrol (federal state), Tyrol and the List of cities and towns in Austria, fifth-largest city in Austria. On the Inn (river), River Inn, at its junction with the Wipptal, Wipp Valley, which provides access to the ...
(1905–1906) and
Vienna
Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...
(from 1909).
Otto Neurath (1882–1945) studied
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 ...
,
political economy
Political or comparative economy is a branch of political science and economics studying economic systems (e.g. Marketplace, markets and national economies) and their governance by political systems (e.g. law, institutions, and government). Wi ...
, and
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 ...
in Vienna and Berlin. From 1907 to 1914 he taught in Vienna at the
Neue Wiener Handelsakademie (Viennese Commercial Academy). Neurath married Olga, Hahn's sister, in 1911.
Philipp Frank, the youngest of the group (1884–1966), studied
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 ...
at Göttingen and Vienna with Ludwig Boltzmann, David Hilbert and Felix Klein. From 1912, he held the chair of
theoretical physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...
in the
German University in Prague.
Their meetings were held in Viennese coffeehouses from 1907 onward. Frank remembered:
A number of further authors were discussed in the meetings such as
Franz Brentano,
Alexius Meinong,
Hermann von Helmholtz
Hermann Ludwig Ferdinand von Helmholtz (; ; 31 August 1821 – 8 September 1894; "von" since 1883) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The ...
,
Heinrich Hertz
Heinrich Rudolf Hertz (; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell's equations of electromagnetism.
Biography
Heinri ...
,
Edmund Husserl
Edmund Gustav Albrecht Husserl (; 8 April 1859 – 27 April 1938) was an Austrian-German philosopher and mathematician who established the school of Phenomenology (philosophy), phenomenology.
In his early work, he elaborated critiques of histori ...
,
Sigmund Freud
Sigmund Freud ( ; ; born Sigismund Schlomo Freud; 6 May 1856 – 23 September 1939) was an Austrian neurologist and the founder of psychoanalysis, a clinical method for evaluating and treating psychopathology, pathologies seen as originating fro ...
,
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 ...
,
Alfred North Whitehead
Alfred North Whitehead (15 February 1861 – 30 December 1947) was an English mathematician and philosopher. He created the philosophical school known as process philosophy, which has been applied in a wide variety of disciplines, inclu ...
,
Vladimir Lenin
Vladimir Ilyich Ulyanov ( 187021 January 1924), better known as Vladimir Lenin, was a Russian revolutionary, politician and political theorist. He was the first head of government of Soviet Russia from 1917 until Death and state funeral of ...
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 ...
.
Presumably the meetings stopped in 1912, when Frank went to
Prague
Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...
, to hold the chair of theoretical physics left vacant by
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 ...
. Hahn left Vienna during
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
and returned in 1921.
Formative years (1918–1924)
The formation of ''the'' Vienna Circle began with Hahn returning to Vienna in 1921. Together with the mathematician
Kurt Reidemeister he organized seminars on
Ludwig Wittgenstein
Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.
From 1929 to 1947, Witt ...
's ''
Tractatus logico-philosophicus
The ''Tractatus Logico-Philosophicus'' (widely abbreviated and Citation, cited as TLP) is the only book-length philosophical work by the Austrian philosopher Ludwig Wittgenstein that was published during his lifetime. The project had a broad goal ...
'' and on Whitehead and Russell's ''
Principia Mathematica
The ''Principia Mathematica'' (often abbreviated ''PM'') is a three-volume work on the foundations of mathematics written by the mathematician–philosophers Alfred North Whitehead and Bertrand Russell and published in 1910, 1912, and 1 ...
''.
With the support of Hahn,
Moritz Schlick was appointed to the chair of philosophy of the inductive sciences at the University of Vienna in 1922 – the chair formerly held by
Ernst Mach and partly by
Boltzmann. Schlick had already published two important works ''Raum und Zeit in die gegenwärtigen Physik'' (''Space and Time in contemporary Physics'') in 1917 and ''Allgemeine Erkenntnislehre'' (''General Theory of Knowledge'') in 1918.
Immediately after Schlick's arrival in Vienna, he organized discussions with the mathematicians around Hahn. In 1924 Schlick's students
Friedrich Waismann and
Herbert Feigl suggested to their teacher a sort of regular "evening circle". From winter term 1924 on regular meetings were held at the Institute of Mathematics in Vienna's Boltzmanngasse 5 on personal invitation by Schlick. These discussions can be seen as the beginning of the Vienna Circle.
Non-public phase – Schlick Circle (1924–1928)
The group that met from 1924 on was quite diverse and included not only recognized scientists such as Schlick, Hahn, Kraft, Philipp Frank, Neurath,
Olga Hahn-Neurath, and
Heinrich Gomperz, but also younger students and doctoral candidates. In addition, the group invited foreign visitors.
In 1926 Schlick and Hahn arranged to bring
Rudolf Carnap
Rudolf Carnap (; ; 18 May 1891 – 14 September 1970) was a German-language philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism.
...
to the University of Vienna as a ''Privatdozent'' (private lecturer). Carnap's ''Logical Structure of the World'' was intensely discussed in the Circle.
Also Wittgenstein's ''Tractatus logico-philosophicus'' was read out loud and discussed. From 1927 on personal meetings were arranged between Wittgenstein and Schlick, Waismann, Carnap and Feigl.
Public phase – Schlick Circle and ''Verein Ernst Mach'' (1928–1934)
In 1928 the ''Verein Ernst Mach'' (''Ernst Mach Society'') was founded, with Schlick as its chairman. The aim of the society was the spreading of a "scientific world conception" through public lectures that were in large part held by members of the Vienna Circle.
In 1929 the Vienna Circle made its first public appearance under this name – invented by Neurath – with the publication of its manifesto ''Wissenschaftliche Weltauffassung. Der Wiener Kreis'' (''The Scientific Conception of the World. The Vienna Circle'' also known as ''Viewing the World Scientifically: The Vienna Circle''
[Edmunds, D. and Eidenow, J. ''Wittgenstein's Poker: The Story of a Ten-Minute Argument Between Two Great Philosophers,'' 2001, page 151.]) The pamphlet is dedicated to Schlick, and its preface was signed by Hahn, Neurath and Carnap.
The manifesto was presented at the ''Tagung für Erkenntnislehre der exakten Wissenschaften'' (''Conference on the Epistemology of the Exact Sciences'') in autumn 1929, organized by the Vienna Circle together with the
Berlin Circle. This conference was the first international appearance of
logical empiricism and the first of a number of conferences:
Königsberg
Königsberg (; ; ; ; ; ; , ) is the historic Germany, German and Prussian name of the city now called Kaliningrad, Russia. The city was founded in 1255 on the site of the small Old Prussians, Old Prussian settlement ''Twangste'' by the Teuton ...
(
1930),
Prague
Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...
(1934),
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
(1935),
Copenhague (1936),
Cambridge
Cambridge ( ) is a List of cities in the United Kingdom, city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, north of London. As of the 2021 Unit ...
, UK (1938),
Cambridge, Mass. (1939), and
Chicago
Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...
(1941).
While primarily known for its views on the natural sciences and metaphysics, the public phase of the Vienna Circle was explicitly political. Neurath and Hahn were both
socialists
Socialism is an economic and political philosophy encompassing diverse economic and social systems characterised by social ownership of the means of production, as opposed to private ownership. It describes the economic, political, and socia ...
and believed the rejection of magic was a necessary component for liberation of the working classes. The manifesto linked
Karl Marx
Karl Marx (; 5 May 1818 – 14 March 1883) was a German philosopher, political theorist, economist, journalist, and revolutionary socialist. He is best-known for the 1848 pamphlet '' The Communist Manifesto'' (written with Friedrich Engels) ...
and
Friedrich Nietzsche
Friedrich Wilhelm Nietzsche (15 October 1844 – 25 August 1900) was a German philosopher. He began his career as a classical philology, classical philologist, turning to philosophy early in his academic career. In 1869, aged 24, Nietzsche bec ...
to their political and anti-metaphysical views, indicating a blur between what are now considered two separate schools of contemporary philosophy –
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 ...
and
continental philosophy
Continental philosophy is a group of philosophies prominent in 20th-century continental Europe that derive from a broadly Kantianism, Kantian tradition.Continental philosophers usually identify such conditions with the transcendental subject or ...
.
In 1930 the Vienna Circle and the Berlin Society took over the journal ''Annalen der Philosophie'' and made it the main journal of logical empiricism under the title ''
Erkenntnis'', edited by Carnap and Reichenbach. In addition, the Vienna Circle published a number of book series: ''Schriften zur wissenschaftlichen Weltauffassung'' (''Monographs on the Scientific World-Conception'', ed. by Schlick und Frank, 1928–1937), ''Einheitswissenschaft'' (''Unified Science'', edited by Neurath, 1933–1939), and later the ''
International Encyclopedia of Unified Science'' (edited by Neurath, Carnap and
Charles W. Morris, 1938–1970).
Disintegration, emigration, internationalization (1934–1938)
From the beginning of the 1930s the first signs of disintegration appeared for political and
racist
Racism is the belief that groups of humans possess different behavioral traits corresponding to inherited attributes and can be divided based on the superiority of one Race (human categorization), race or ethnicity over another. It may also me ...
reasons:
Herbert Feigl left Austria in 1930. Carnap was appointed to a chair at
Prague University in 1931 and left for Chicago in 1935.
1934 marks an important break: Hahn died after surgery, Neurath fled to Holland because of the victory of
Austrofascism in the
Austrian Civil War
The Austrian Civil War () of 12–15 February 1934, also known as the February Uprising () or the February Fights (), was a series of clashes in the First Austrian Republic between the forces of the authoritarian Fatherland Front (Austria), rig ...
following which the ''Ernst Mach Society'' was dissolved for political reasons by the
Schuschnigg regime.
The murder of Moritz Schlick by the former student
Hans Nelböck for political and personal reasons in 1936 set an end to the meetings of the Schlick Circle.
Some members of the circle such as Kraft, Waismann, Zilsel, Menger and Gomperz continued to meet occasionally. But the
annexation of Austria to
Nazi Germany
Nazi Germany, officially known as the German Reich and later the Greater German Reich, was the German Reich, German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a Totalit ...
in 1938 meant the definite end of the activities of the Vienna Circle in Austria.
With the emigration went along the internationalization of
logical empiricism. Many former members of the Vienna Circle and the
Berlin Circle emigrated to the
English-speaking world
The English-speaking world comprises the 88 countries and territories in which English language, English is an official, administrative, or cultural language. In the early 2000s, between one and two billion people spoke English, making it the ...
where they had an immense influence on the development of
philosophy of science
Philosophy of science is the branch of philosophy concerned with the foundations, methods, and implications of science. Amongst its central questions are the difference between science and non-science, the reliability of scientific theories, ...
. The
unity of science movement for the construction of an ''International Encyclopedia of Unified Science'', promoted mainly by Neurath, Carnap, and Morris, is symptomatic of the internationalization of logical empiricism, organizing numerous international conferences and the publication of the ''International Encyclopedia of Unified Science''.
Overview of the members
Apart from the central figures of the Schlick Circle the question of membership in the Vienna Circle is in many cases unsettled. The partition into "members" and "those sympathetic to the Vienna Circle" produced in the manifesto from 1929 is representative only of a specific moment in the development of the Circle. Depending on the criteria used (regular attendance, philosophical affinities etc.) there are different possible distributions in "inner circle" and "periphery".
In the following list (in alphabetical order), the "inner circle" is defined using the criterion of regular attendance. The "periphery" comprises occasional visitors, foreign visitors and leading intellectual figures who stood in regular contact with the Circle (such as Wittgenstein and Popper).
Inner Circle:
Gustav Bergmann,
Rudolf Carnap
Rudolf Carnap (; ; 18 May 1891 – 14 September 1970) was a German-language philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism.
...
,
Herbert Feigl,
Philipp Frank,
Kurt Gödel
Kurt Friedrich Gödel ( ; ; April 28, 1906 – January 14, 1978) was a logician, mathematician, and philosopher. Considered along with Aristotle and Gottlob Frege to be one of the most significant logicians in history, Gödel profoundly ...
,
Hans Hahn,
Olga Hahn-Neurath,
Béla Juhos,
Felix Kaufmann,
Victor Kraft,
Karl Menger
Karl Menger (; January 13, 1902 – October 5, 1985) was an Austrian-born American mathematician, the son of the economist Carl Menger. In mathematics, Menger studied the theory of algebra over a field, algebras and the dimension theory of low-r ...
,
Richard von Mises,
Otto Neurath,
Rose Rand,
Josef Schächter,
Moritz Schlick,
Friedrich Waismann,
Edgar Zilsel.
Periphery:
Alfred Jules Ayer,
Egon Brunswik,
Karl Bühler,
Josef Frank,
Else Frenkel-Brunswik,
Heinrich Gomperz,
Carl Gustav Hempel
Carl Gustav "Peter" Hempel (; ; January 8, 1905 – November 9, 1997) was a German writer, philosopher, logician, and epistemologist. He was a major figure in Logical positivism, logical empiricism, a 20th-century movement in the philosophy ...
,
Eino Kaila,
Hans Kelsen
Hans Kelsen (; ; October 11, 1881 – April 19, 1973) was an Austrian and later American jurist, legal philosopher and political philosopher. He is known principally for his theory of law, which he named the " pure theory of law (''Reine Rechts ...
,
Charles W. Morris,
Arne Naess,
Karl Raimund Popper,
Willard Van Orman 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 century" ...
,
Frank P. Ramsey
Frank Plumpton Ramsey (; 22 February 1903 – 19 January 1930) was a British people, British philosopher, mathematician, and economist who made major contributions to all three fields before his death at the age of 26. He was a close friend of ...
,
Hans Reichenbach
Hans Reichenbach (; ; September 26, 1891 – April 9, 1953) was a leading philosopher of science, educator, and proponent of logical empiricism. He was influential in the areas of science, education, and of logical empiricism. He founded the ''G ...
,
Kurt Reidemeister,
Alfred Tarski
Alfred Tarski (; ; born Alfred Teitelbaum;School of Mathematics and Statistics, University of St Andrews ''School of Mathematics and Statistics, University of St Andrews''. January 14, 1901 – October 26, 1983) was a Polish-American logician ...
,
Olga Taussky-Todd
Olga Taussky-Todd (August 30, 1906 – October 7, 1995) was an Austrian and later Czech Americans, Czech-American mathematician. She published more than 300 research papers on algebraic number theory, integral matrices, and Matrix (mathematics), ...
,
Ludwig Wittgenstein
Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.
From 1929 to 1947, Witt ...
.
Reception in the United States and the United Kingdom
The spread of
logical positivism in the United States occurred throughout the 1920s and 1930s. In 1929 and in 1932, Schlick was a visiting professor at
Stanford, while Feigl, who immigrated to the United States in 1930, became lecturer (1931) and professor (1933) at the
University of Iowa
The University of Iowa (U of I, UIowa, or Iowa) is a public university, public research university in Iowa City, Iowa, United States. Founded in 1847, it is the oldest and largest university in the state. The University of Iowa is organized int ...
. The definite diffusion of logical positivism in the United States was due to Carl Hempel, Hans Reichenbach, Rudolf Carnap, Philipp Frank, and Herbert Feigl, who emigrated and taught in the United States.
Another link to the United States is
Willard Van Orman 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 century" ...
, who traveled in 1932 and 1933 as a Sheldon Traveling Fellow to
Vienna
Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...
,
Prague
Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...
, and
Warsaw
Warsaw, officially the Capital City of Warsaw, is the capital and List of cities and towns in Poland, largest city of Poland. The metropolis stands on the Vistula, River Vistula in east-central Poland. Its population is officially estimated at ...
. Moreover, American
semiotician and philosopher
Charles W. Morris helped many German and Austrian philosophers emigrate to the United States, including Rudolf Carnap, in 1936.
In the United Kingdom it was
Alfred Jules Ayer who acquainted the British academia with the work of the Vienna Circle with his book ''
Language, Truth, and Logic'' (1936).
Karl Popper
Sir Karl Raimund Popper (28 July 1902 – 17 September 1994) was an Austrian–British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the ...
was also important for the reception and critique of their work, even though he never participated in the meetings of the Vienna Circle.
Congresses and publications
The Vienna Circle was very active in advertising their new philosophical ideas. Several congresses on
epistemology
Epistemology is the branch of philosophy that examines the nature, origin, and limits of knowledge. Also called "the theory of knowledge", it explores different types of knowledge, such as propositional knowledge about facts, practical knowle ...
and philosophy of science were organized, with the help of the
Berlin Circle. There were some preparatory congresses: Prague (1929),
Königsberg
Königsberg (; ; ; ; ; ; , ) is the historic Germany, German and Prussian name of the city now called Kaliningrad, Russia. The city was founded in 1255 on the site of the small Old Prussians, Old Prussian settlement ''Twangste'' by the Teuton ...
(1930), Prague (1934) and then the first congress on scientific philosophy held in
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...
(1935), followed by congresses in
Copenhagen
Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...
(1936), Paris (1937),
Cambridge
Cambridge ( ) is a List of cities in the United Kingdom, city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, north of London. As of the 2021 Unit ...
, UK (1938),
Cambridge, Massachusetts
Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, ...
. (1939). The
Königsberg congress (1930) was very important, for Kurt Gödel announced that he had proven the
completeness of
first-order 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 over ...
and the
incompleteness of formal
arithmetic
Arithmetic is an elementary branch of mathematics that deals with numerical operations like addition, subtraction, multiplication, and division. In a wider sense, it also includes exponentiation, extraction of roots, and taking logarithms.
...
. Another very interesting congress was the one held in Copenhagen (1936), which was dedicated to
quantum physics
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 ...
and
causality.
Between 1928 and 1937, the Vienna Circle published ten books in a collection named ''Schriften zur wissenschaftlichen Weltauffassung'' (''Monographs on the Scientific World-Conception''), edited by Schlick and Frank.
Karl Raimund Popper's book ''Logik der Forschung'' was published in this collection. Seven works were published in another collection, called ''Einheitswissenschaft'' (''Unified Science''). In 1930 Rudolf Carnap and Hans Reichenbach undertook the editorship of the journal ''Erkenntnis'', which was published between 1930 and 1940 (from 1939 the editors were Otto Neurath, Rudolf Carnap and Charles Morris).
The following is the list of works published in the two collections edited by the Vienna Circle.
''Schriften zur wissenschaftlichen Weltauffassung'' (''Monographs on the Scientific World-Conception''), edited by Schlick and Frank:
*
Richard von Mises, ''Wahrscheinlichkeit, Statistik und Wahrheit'', 1928 (''Probability, Statistics, and Truth'', New York: Macmillan company, 1939)
* Rudolf Carnap, ''Abriss der Logistik'', 1929
* Moritz Schlick, ''Fragen der Ethik'', 1930 (''Problems of Ethics'', New York: Prentice-Hall, 1939)
* Otto Neurath, ''Empirische Soziologie'', 1931
* Philipp Frank, ''Das Kausalgesetz und seine Grenzen'', 1932 (''The Law of Causality and its Limits'', Dordrecth; Boston: Kluwer, 1997)
* Otto Kant, ''Zur Biologie der Ethik'', 1932
* Rudolf Carnap, ''Logische Syntax der Sprache'', 1934 (''The Logical Syntax of Language'', New York: Humanities, 1937)
* Karl Raimund Popper, ''Logik der Forschung'', 1934 (''The Logic of Scientific Discovery'', New York: Basic Books, 1959)
*
Josef Schächter, ''Prolegomena zu einer kritischen Grammatik'', 1935 (''Prolegomena to a Critical Grammar'', Dordrecht; Boston: D. Reidel Pub. Co., 1973)
* Victor Kraft, ''Die Grundlagen einer wissenschaftliche Wertlehre'', 1937 (''Foundations for a Scientific Analysis of Value'', Dordrecht; Boston: D. Reidel Pub. Co., 1981)
''Einheitswissenschaft'' (''Unified Science''), edited by Carnap, Frank, Hahn, Neurath,
Jørgensen (after Hahn's death), Morris (from 1938):
* Hans Hahn, ''Logik, Mathematik und Naturerkennen'', 1933
* Otto Neurath, ''Einheitswissenschaft und Psychologie'', 1933
* Rudolf Carnap, ''Die Aufgabe der Wissenschaftlogik'', 1934
* Philipp Frank, ''Das Ende der mechanistischen Physik'', 1935
* Otto Neurath, ''Was bedeutet rationale Wirtschaftsbetrachtung'', 1935
* Otto Neurath,
E. Brunswik, C. Hull,
G. Mannoury, J. Woodger, ''Zur Enzyklopädie der Einheitswissenschaft''. Vorträge, 1938
* Richard von Mises, ''Ernst Mach und die empiristische Wissenschaftauffassung'', 1939
These works are translated in ''Unified Science: The Vienna Circle Monograph Series Originally Edited by Otto Neurath'', Kluwer, 1987.
Monographs, arranged in chronological order, published in the ''
International Encyclopedia of Unified Science'':
* Otto Neurath, Niels Bohr,
John Dewey
John Dewey (; October 20, 1859 – June 1, 1952) was an American philosopher, psychologist, and Education reform, educational reformer. He was one of the most prominent American scholars in the first half of the twentieth century.
The overridi ...
,
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 ...
, Rudolf Carnap, Charles Morris, ''Encyclopedia and unified science'', 1938, vol.1 n.1
* Charles Morris, ''Foundations of the theory of signs'', 1938, vol.1 n.2
*
Victor Lenzen, ''Procedures of empirical sciences'', 1938, vol.1 n.5
* Rudolf Carnap, ''Foundations of logic and mathematics'', 1939, vol.1 n.3
*
Leonard Bloomfield
Leonard Bloomfield (April 1, 1887 – April 18, 1949) was an American linguist who led the development of structural linguistics in the United States during the 1930s and the 1940s. He is considered to be the father of American distributionalis ...
, ''Linguistic aspects of science'', 1939, vol.1 n.4
*
Ernest Nagel, ''Principles of the theory of probability'', 1939, vol.1 n.6
*
John Dewey
John Dewey (; October 20, 1859 – June 1, 1952) was an American philosopher, psychologist, and Education reform, educational reformer. He was one of the most prominent American scholars in the first half of the twentieth century.
The overridi ...
, ''Theory of valuation'', 1939, vol.2 n.4
*
Giorgio de Santillana and
Edgar Zilsel, ''The development of rationalism and empiricism'', 1941, vol.2 n.8
* Otto Neurath, ''Foundations of social sciences'', 1944, vol.2 n.1
*
Joseph H. Woodger, ''The technique of theory construction'', 1949, vol.2 n.5
* Philipp Frank, ''Foundations of physics'', 1946, vol.1 n.7
*
Erwin Finlay-Freundlich, ''Cosmology'', 1951, vol.1 n.8
*
Jørgen Jørgensen, ''The development of logical empiricism'', 1951, vol.2 n.9
*
Egon Brunswik, ''The conceptual framework of psychology'', 1952, vol.1 n.10
*
Carl Hempel, ''Fundamentals of concept formation in empirical science'', 1952, vol.2 n.7
* Felix Mainx, ''Foundations of biology'', 1955, vol.1 n.9
*
Abraham Edel, ''Science and the structure of ethics'', 1961, vol.2 n.3
*
Thomas S. Kuhn, ''The structure of scientific revolutions'', 1962, vol.2 n.2
*
Gerhard Tintner, ''Methodology of mathematical economics and econometrics'', 1968, vol.2 n.6
* Herbert Feigl and Charles Morris, ''Bibliography and index'', 1969, vol.2 n.10
Topics and debates
The Vienna Circle cannot be assigned ''one'' single philosophy. First, there existed a plurality of philosophical positions within the Circle, and second, members often changed their views fundamentally in the course of time and in reaction to discussions in the Circle. It thus seems more convenient to speak of "the philosophies (in the plural) of the Vienna Circle".
However, some central topics and debates can be identified.
The Manifesto (1929)
This states the scientific world-conception of the Vienna Circle, which is characterized "essentially by two features. First it is
empiricist and positivist: there is knowledge only from experience. Second, the scientific world-conception is marked by the application of a certain method, namely
logical analysis."
Logical analysis is the method of clarification of philosophical problems; it makes an extensive use of
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 ...
and distinguishes the Vienna Circle empiricism from earlier versions. The task of philosophy lies in the clarification—through the method of logical analysis—of problems and assertions.
Logical analysis shows that there are two different kinds of statements; one kind includes statements reducible to simpler statements about the empirically given; the other kind includes statements which cannot be reduced to statements about
experience
Experience refers to Consciousness, conscious events in general, more specifically to perceptions, or to the practical knowledge and familiarity that is produced by these processes. Understood as a conscious event in the widest sense, experience i ...
and thus they are devoid of meaning.
Metaphysical
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 h ...
statements belong to this second kind and therefore they are meaningless. Hence many philosophical problems are rejected as pseudo-problems which arise from logical mistakes, while others are re-interpreted as empirical statements and thus become the subject of scientific inquiries.
One source of the logical mistakes that are at the origins of metaphysics is the ambiguity of natural
language
Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and signed language, signed forms, and may also be conveyed through writing syste ...
. "Ordinary language for instance uses the same
part of speech
In grammar, a part of speech or part-of-speech ( abbreviated as POS or PoS, also known as word class or grammatical category) is a category of words (or, more generally, of lexical items) that have similar grammatical properties. Words that are ...
, the substantive, for
things ('apple') as well as for
qualities ('hardness'), relations ('friendship'), and processes ('sleep'); therefore it misleads one into a thing-like conception of functional
concept
A concept is an abstract idea that serves as a foundation for more concrete principles, thoughts, and beliefs.
Concepts play an important role in all aspects of cognition. As such, concepts are studied within such disciplines as linguistics, ...
s". Another source of mistakes is "the notion that ''thinking'' can either lead to knowledge out of its own resources without using any empirical material, or at least arrive at new contents by an
inference
Inferences are steps in logical reasoning, moving from premises to logical consequences; etymologically, the word '' infer'' means to "carry forward". Inference is theoretically traditionally divided into deduction and induction, a distinct ...
from given states of affair".
Synthetic knowledge a priori is rejected by the Vienna Circle. Mathematics, which at first sight seems an example of necessarily valid synthetic knowledge derived from pure
reason
Reason is the capacity of consciously applying logic by drawing valid conclusions from new or existing information, with the aim of seeking the truth. It is associated with such characteristically human activities as philosophy, religion, scien ...
alone, has instead a
tautological character, that is its statements are
analytical statements, thus very different from Kantian synthetic statements. The only two kinds of statements accepted by the Vienna Circle are synthetic statements ''
a posteriori'' (i.e., scientific statements) and analytic statements ''
a priori
('from the earlier') and ('from the later') are Latin phrases used in philosophy to distinguish types of knowledge, Justification (epistemology), justification, or argument by their reliance on experience. knowledge is independent from any ...
'' (i.e., logical and mathematical statements).
However, the persistence of metaphysics is connected not only with logical mistakes but also with "social and economical struggles".
[''VC'' p. 339] Metaphysics 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 ...
are allied to traditional social forms, while the group of people who "faces modern times, rejects these views and takes its stand on the ground of empirical sciences".
Thus the struggle between metaphysics and
scientific world-conception is not only a struggle between different kinds of philosophies, but it is also—and perhaps primarily—a struggle between different political, social, and economical attitudes. Of course, as the manifesto itself acknowledged, "not every adherent of the scientific world-conception will be a fighter". Many historians of the Vienna Circle see in the latter sentence an implicit reference to a contrast between the so-called 'left wing' of the Vienna Circle, mainly represented by Neurath and Carnap, and Moritz Schlick. The aim of the left wing was to facilitate the penetration of the scientific world-conception in "the forms of personal and public life, in
education
Education is the transmission of knowledge and skills and the development of character traits. Formal education occurs within a structured institutional framework, such as public schools, following a curriculum. Non-formal education als ...
, upbringing,
architecture
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and construction, constructi ...
, and the shaping of economic and social life". In contrast, Schlick was primarily interested in the theoretical study of science and philosophy. Perhaps the sentence "Some, glad of solitude, will lead a withdrawn existence on the icy slopes of logic" is an ironic reference to Schlick.
The manifesto lists
Walter Dubislav,
Josef Frank,
Kurt Grelling, Hasso Härlen,
Eino Kaila, Heinrich Loewy,
F. P. Ramsey,
Hans Reichenbach
Hans Reichenbach (; ; September 26, 1891 – April 9, 1953) was a leading philosopher of science, educator, and proponent of logical empiricism. He was influential in the areas of science, education, and of logical empiricism. He founded the ''G ...
,
Kurt Reidemeister, and
Edgar Zilsel as people "sympathetic to the Vienna Circle" and
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 ...
,
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 ...
, and
Ludwig Wittgenstein
Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.
From 1929 to 1947, Witt ...
as "leading representatives of the scientific world-conception".
Unified science
The final goal pursued by the Vienna Circle was
unified science, that is the construction of a "constitutive system" in which every legitimate statement is reduced to the concepts of lower level which refer directly to the given
experience
Experience refers to Consciousness, conscious events in general, more specifically to perceptions, or to the practical knowledge and familiarity that is produced by these processes. Understood as a conscious event in the widest sense, experience i ...
. "The endeavour is to link and harmonise the achievements of individual investigators in their various fields of science". From this aim follows the search for clarity, neatness, and for a symbolic language that eliminates the problems arising from the ambiguity of natural language. The Vienna Circle published a collection, called ''Einheitswissenschaft'' (''Unified Science''), edited by Rudolf Carnap, Philipp Frank, Hans Hahn, Otto Neurath,
Jørgen Jørgensen (after Hahn's death) and
Charles W. Morris (from 1938), whose aim was to present a unified vision of science. After the publication in
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
of seven monographs from 1933 to 1939, the collection was dismissed, because of the problems arising from the
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. In 1938 a new series of publications started in the United States. It was the ''
International Encyclopedia of Unified Science'', an ambitious project never completed devoted to unified science. Only the first section ''Foundations of the Unity of Sciences'' was published; it contains two volumes for a total of twenty monographs published from 1938 to 1969. As remembered by Rudolf Carnap and Charles Morris in the ''Preface'' to the 1969 edition of the International Encyclopedia of Unified Science:
Thomas Kuhn
Thomas Samuel Kuhn (; July 18, 1922 – June 17, 1996) was an American History and philosophy of science, historian and philosopher of science whose 1962 book ''The Structure of Scientific Revolutions'' was influential in both academic and ...
's well known work, ''
The Structure of Scientific Revolutions
''The Structure of Scientific Revolutions'' is a 1962 book about the history of science by the philosopher Thomas S. Kuhn. Its publication was a landmark event in the History of science, history, Philosophy of science, philosophy, and sociology ...
'', was published in this Encyclopedia in 1962, as the number two in the second volume.
Critique of metaphysics
The attitude of Vienna Circle towards metaphysics is well expressed by Carnap in the article 'Überwindung der Metaphysik durch Logische Analyse der Sprache' in ''Erkenntnis'', vol. 2, 1932 (English translation 'The Elimination of Metaphysics Through Logical Analysis of Language' in Sarkar, Sahotra, ed., ''Logical empiricism at its peak: Schlick, Carnap, and Neurath'', New York : Garland Pub., 1996, pp. 10–31). A language—says Carnap—consists of a
vocabulary
A vocabulary (also known as a lexicon) is a set of words, typically the set in a language or the set known to an individual. The word ''vocabulary'' originated from the Latin , meaning "a word, name". It forms an essential component of languag ...
, i.e., a set of meaningful words, and a
syntax
In linguistics, syntax ( ) is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure (constituenc ...
, i.e., a set of rules governing the formation of sentences from the words of the vocabulary. Pseudo-statements, i.e., sequences of words that at first sight resemble statements but in reality have no meaning, are formed in two ways: either meaningless words occur in them, or they are formed in an invalid syntactical way. According to Carnap, pseudo-statements of both kinds occur in metaphysics.
A word ''W'' has a meaning if two conditions are satisfied. First, the mode of the occurrence of ''W'' in its elementary sentence form (i.e., the simplest sentence form in which ''W'' is capable of occurring) must be fixed. Secondly, if ''W'' occurs in an elementary sentence ''S'', it is necessary to give an answer to the following questions (that are—according to Carnap—equivalent formulation of the same question):
* What
sentences is ''S'' deducible from, and what sentences are deducible from ''S''?
* Under what conditions is ''S'' supposed to be true, and under what conditions false?
* How is ''S'' verified?
* What is the meaning of ''S''?
(Carnap, "The Elimination of Metaphysics Through Logical Analysis of Language" in Sarkar, Sahotra 1996, p. 12)
An example offered by Carnap concerns the word '
arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
'. The sentence form "the thing ''x'' is an arthropod" is an elementary sentence form that is derivable from "''x'' is an animal", "''x'' has a segmented body" and "''x'' has jointed legs". Conversely, these sentences are derivable from "the thing ''x'' is an arthropod". Thus the meaning of the word 'arthropod' is determined.
According to Carnap, many words of metaphysics do not fulfill these requirements and thus they are meaningless. As an example, Carnap considers the word 'principle'. This word has a definite meaning, if the sentence "''x'' is the principle of ''y''" is supposed to be equivalent to the sentence "''y'' exists by virtue of ''x''" or "''y'' arises out of ''x''". The latter sentence is perfectly clear: ''y'' arises out of ''x'' when ''x'' is invariably followed by ''y'', and the invariable association between ''x'' and ''y'' is empirically verifiable. But—says Carnap—metaphysicians are not satisfied with this interpretation of the meaning of 'principle'. They assert that no empirical relation between ''x'' and ''y'' can completely explain the meaning of "''x'' is the principle of ''y''", because there is something that cannot be grasped by means of the experience, something for which no empirical criterion can be specified. It is the lacking of any empirical criterion—says Carnap—that deprives of meaning the word 'principle' when it occurs in metaphysics. Therefore, metaphysical pseudo-statements such as "water is the principle of the world" or "the spirit is the principle of the world" are void of meaning because a meaningless word occurs in them.
However, there are pseudo-statements in which occur only meaningful words; these pseudo-statements are formed in a counter-syntactical way. An example is the word sequence "Caesar is a
prime number
A prime number (or a prime) is a natural number greater than 1 that is not a Product (mathematics), 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 ...
"; every word has a definite meaning, but the sequence has no meaning. The problem is that "prime number" is a predicate of numbers, not a predicate of human beings. In the example the nonsense is evident; however, in natural language the rules of grammar do not prohibit the formation of analogous meaningless word sequences that are not so easily detectable. In the grammar of natural languages, every sequence of the kind "''x'' is ''y''", where ''x'' is a noun and ''y'' is a predicate, is acceptable. In fact, in the grammar there is no distinction between predicate which can be affirmed of human beings and predicate which can be affirmed of numbers. So "Caesar is a general" and "Caesar is a prime number" are both well-formed, in contrast for example with "Caesar is and", which is ill-formed. In a logically constructed language—says Carnap—a distinction between the various kinds of predicate is specified, and pseudo-statements as "Caesar is a prime number" are ill-formed. Now, and this is the main point of Carnap's argument, metaphysical statements in which meaningless words do not occur, are indeed meaningless because they are formed in a way which is admissible in natural languages, but not in logically constructed languages. Carnap attempts to indicate the most frequent sources of errors from which metaphysical pseudo-statements can arise. One source of mistakes is the ambiguity of the verb "to be", which is sometimes used as a
copula ("I am hungry"), and sometimes to designate existence ("I am"). The latter statement incorrectly suggests a predicative form, and thus it suggests that existence is a predicate. Only modern logic, with the introduction of an explicit sign to designate existence (the sign
), which occurs only in statements such as
, never as a predicate, has shown that existence is not a predicate, and thus has revealed the logical error from which pseudo-statements such as "cogito, ergo sum" has arisen.
Another source of mistakes is type confusions, in which a predicate of a kind is used as a predicate of another kind. For example, the pseudo-statements "we know the Nothing" is analogous to "we know the rain", but while the latter is well-formed, the former is ill-formed, at least in a logically constructed language, because "Nothing" is incorrectly used as a
noun
In grammar, a noun is a word that represents a concrete or abstract thing, like living creatures, places, actions, qualities, states of existence, and ideas. A noun may serve as an Object (grammar), object or Subject (grammar), subject within a p ...
. In a formal language, "Nothing" only means
, such as "there is nothing which is outside"—i.e.,
, and thus "Nothing" never occurs as a noun or as a predicate.
According to Carnap, although metaphysics has no theoretical content, it does have content: metaphysical pseudo-statements express the attitude of a person towards life, and this is the role of metaphysics. He compares it to an art like lyrical poetry; the metaphysician works with the medium of the theoretical; he confuses art with science, attitude towards life with knowledge, and thus produces an unsatisfactory and inadequate work. "Metaphysicians are musicians without musical ability".
Institute Vienna Circle / Vienna Circle Society
In 1991 the
Institute Vienna Circle (IVC) was established as a society in Vienna. It is dedicated to studying the work and influence of the Vienna Circle. In 2011 it was integrated in the
University of Vienna
The University of Vienna (, ) is a public university, public research university in Vienna, Austria. Founded by Rudolf IV, Duke of Austria, Duke Rudolph IV in 1365, it is the oldest university in the German-speaking world and among the largest ...
as a subunit of the Faculty of Philosophy and Education.
Since 2016 the former society continues its activities in close cooperation with the IVC under the changed name Vienna Circle Society (VCS). In 2015 the institute co-organized an exhibition on the Vienna Circle in the main building of the University of Vienna.
See also
*
Formalism (mathematics)
*
Logical behaviorism
*
Logicism
In the philosophy of mathematics, logicism is a programme comprising one or more of the theses that – for some coherent meaning of 'logic' – mathematics is an extension of logic, some or all of mathematics is reducible to logic, or some or al ...
*
List of Austrian intellectual traditions
*
Mastermind group
Notes
Bibliography
Primary literature
* Carnap, Rudolf. "Überwindung der Metaphysik durch Logische Analyse der Sprache" in ''Erkenntnis'', vol. 2, 1932 (English translation "The Elimination of Metaphysics Through Logical Analysis of Language" in Sarkar, Sahotra, ed., ''Logical empiricism at its peak: Schlick, Carnap, and Neurath'', New York : Garland Pub., 1996, pp. 10–31)
* Neurath, Otto and Carnap, Rudolf and Morris, Charles W. ''Foundations of the Unity of Sciences'', vol. 1, Chicago : The University of Chicago Press, 1969.
* ''Wissenschaftliche Weltauffassung. Der Wiener Kreis'', 1929. English translation ''The Scientific Conception of the World. The Vienna Circle'' in Sarkar, Sahotra, ed., ''The Emergence of Logical Empiricism: from 1900 to the Vienna Circle'', New York : Garland Publishing, 1996, pp. 321–340
* Stadler, Friedrich and Uebel, Thomas (eds.): ''Wissenschaftliche Weltauffassung. Der Wiener Kreis. Hrsg. vom Verein Ernst Mach (1929).'' Reprint of the first edition. With translations into English, French, Spanish and Italian. Vienna: Springer, 2012.
* Stöltzner, Michael and Uebel, Thomas (eds.). ''Wiener Kreis. Texte zur wissenschaftlichen Weltauffassung''. Meiner, Hamburg, 2006, . (Anthology in German)
Secondary literature
* Arnswald, Ulrich,
Stadler, Friedrich and Weibel, Peter (ed.): ''Der Wiener Kreis – Aktualität in Wissenschaft, Literatur, Architektur und Kunst.'' Wien: LIT Verlag 2019.
* Ayer, Alfred Jules. ''Language, Truth and Logic.''
London
London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...
, Victor Gollancz, 1936.
* Ayer, Alfred Jules. ''Logical Positivism''. Glencoe, Ill: Free Press, 1959.
* Barone, Francesco. ''Il neopositivismo logico''. Roma Bari: Laterza, 1986.
*
Bergmann, Gustav. ''The Metaphysics of Logical Positivism''. New York: Longmans Green, 1954.
* Cirera, Ramon. ''Carnap and the Vienna Circle: Empiricism and Logical Syntax''. Atlanta, GA: Rodopi, 1994.
*
*
Frank, Philipp: ''Modern Science and its Philosophy''. Cambridge, 1949.
*
Friedman, Michael, ''Reconsidering Logical Positivism''. Cambridge, UK: Cambridge University Press, 1999.
* Gadol, Eugene T. ''Rationality and Science: A Memorial Volume for Moritz Schlick in Celebration of the Centennial of his Birth''. Wien: Springer, 1982.
*
Geymonat, Ludovico. ''La nuova filosofia della natura in Germania''. Torino, 1934.
*
Giere, Ronald N. and Richardson, Alan W. ''Origins of Logical Empiricism''. Minneapolis: University of Minnesota Press, 1997.
* Haller, Rudolf. ''Neopositivismus. Eine historische Einführung in die Philosophie des Wiener Kreises''. Wissenschaftliche Buchgesellschaft, Darmstadt, 1993, . (German)
*
Holt, Jim. "Positive Thinking" (review of
Karl Sigmund, ''Exact Thinking in Demented Times: The Vienna Circle and the Epic Quest for the Foundations of Science'', Basic Books, 449 pp.), ''
The New York Review of Books
''The New York Review of Books'' (or ''NYREV'' or ''NYRB'') is a semi-monthly magazine with articles on literature, culture, economics, science and current affairs. Published in New York City, it is inspired by the idea that the discussion of ...
'', vol. LXIV, no. 20 (21 December 2017), pp. 74–76.
*
Kraft, Victor. ''The Vienna Circle: The Origin of Neo-positivism, a Chapter in the History of Recent Philosophy''. New York: Greenwood Press, 1953.
* Limbeck, Christoph and Stadler, Friedrich (eds.). ''The Vienna Circle. Texts and Pictures of an Exhibition.'' Münster-Berlin-London 2015.
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McGuinness, Brian. ''Wittgenstein and the Vienna Circle: Conversations Recorded by Friedrich Waismann''. Trans. by Joachim Schulte and Brian McGuinness. New York: Barnes & Noble Books, 1979.
* Parrini, Paolo;
Salmon, Wesley C.; Salmon, Merrilee H. (ed.) ''Logical Empiricism – Historical and Contemporary Perspectives'', Pittsburgh: University of Pittsburgh Press, 2003.
* Reisch, George. ''How the Cold War Transformed Philosophy of Science : To the Icy Slopes of Logic''. New York: Cambridge University Press, 2005.
*
Rescher, Nicholas (ed.). ''The Heritage of Logical Positivism''. University Press of America, 1985.
* Richardson, Alan W. "The Scientific World Conception. Logical Positivism", in: T. Baldwin (Hg.), ''The Cambridge History of Philosophy'', 1870–1945, 2003, 391–400.
* Richardson, Alan W. and Uebel, Thomas (ed.). ''The Cambridge Companion to Logical Empiricism''. Cambridge, 2007.
* Salmon, Wesley and Wolters, Gereon (ed.), ''Logic, Language, and the Structure of Scientific Theories: Proceedings of the Carnap-Reichenbach Centennial, University of Konstanz, 21–24 May 1991'', Pittsburgh: University of Pittsburgh Press, 1994.
*
Sarkar, Sahotra. ''The Emergence of Logical Empiricism: From 1900 to the Vienna Circle''. New York: Garland Publishing, 1996.
* Sarkar, Sahotra. ''Logical Empiricism at its Peak: Schlick, Carnap, and Neurath''. New York: Garland Pub., 1996.
* Sarkar, Sahotra. ''Logical Empiricism and the Special Sciences: Reichenbach, Feigl, and Nagel''. New York: Garland Pub., 1996.
* Sarkar, Sahotra. ''Decline and Obsolescence of Logical Empiricism: Carnap vs. Quine and the Critics''. New York: Garland Pub., 1996.
* Sarkar, Sahotra. ''The Legacy of the Vienna Circle: Modern Reappraisals''. New York: Garland Pub., 1996.
*
Spohn, Wolfgang (ed.), ''Erkenntnis Orientated: A Centennial Volume for Rudolf Carnap and Hans Reichenbach'', Boston: Kluwer Academic Publishers, 1991.
*
Stadler, Friedrich. ''The Vienna Circle. Studies in the Origins, Development, and Influence of Logical Empiricism.'' New York: Springer, 2001. – 2nd Edition: Dordrecht: Springer, 2015.
* Stadler, Friedrich (ed.). ''The Vienna Circle and Logical Empiricism. Re-evaluation and Future Perspectives.'' Dordrecht – Boston London, Kluwer, 2003.
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Uebel, Thomas. ''Vernunftkritik und Wissenschaft: Otto Neurath und der erste Wiener Kreis.'' Wien-New York 2000. (German)
* Uebel, Thomas, "On the Austrian Roots of Logical Empiricism" in ''Logical Empiricism – Historical and contemporary Perspectives'', ed. Paolo Parrini, Wesley C. Salmon, Merrilee H. Salmon, Pittsburgh : University of Pittsburgh Press, 2003, pp. 76–93.
External links
Institute Vienna CircleVienna Circle Foundation AmsterdamThomas Uebel, "Vienna Circle", ''The Stanford Encyclopedia of Philosophy''
{{Authority control
Logical positivism
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Science studies
Philosophy of science
Epistemology
Epistemology of science
1924 establishments in Austria