Hans Reichenbach (September 26, 1891 – April 9, 1953) was a leading philosopher of science,

educator A teacher, also called a schoolteacher or formally an educator, is a person who helps students to acquire knowledge, competence, or virtue, via the practice of teaching. ''Informally'' the role of teacher may be taken on by anyone (e.g. whe ...

, and proponent of logical empiricism. He was influential in the areas of

science Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence ...

education Education is a purposeful activity directed at achieving certain aims, such as transmitting knowledge or fostering skills and character traits. These aims may include the development of understanding, rationality, kindness, and honesty ...

, and of logical empiricism. He founded the ''Gesellschaft für empirische Philosophie'' (Society for Empirical Philosophy) in Berlin in 1928, also known as the “ Berlin Circle”.

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 empiricism, a 20th-century movement in the philosophy of science. He is e ...

Richard von Mises Richard Edler von Mises (; 19 April 1883 – 14 July 1953) was an Austrian scientist and mathematician who worked on solid mechanics, fluid mechanics, aerodynamics, aeronautics, statistics and probability theory. He held the position of Gordo ...

David Hilbert David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician, one of the most influential mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many ...

and Kurt Grelling all became members of the Berlin Circle. In 1930, Reichenbach and

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. ...

became editors of the journal '' Erkenntnis''. He also made lasting contributions to the study of

empiricism In philosophy, empiricism is an epistemological theory that holds that knowledge or justification comes only or primarily from sensory experience. It is one of several views within epistemology, along with rationalism and skepticism. Empir ...

based on a theory of probability; the

logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from prem ...

and the

philosophy of mathematics The philosophy of mathematics is the branch of philosophy that studies the assumptions, foundations, and implications of mathematics. It aims to understand the nature and methods of mathematics, and find out the place of mathematics in people' ...

;

space Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consi ...

time Time is the continued sequence of existence and event (philosophy), events that occurs in an apparently irreversible process, irreversible succession from the past, through the present, into the future. It is a component quantity of various me ...

, and

relativity theory The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena ...

; analysis of

probabilistic Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, ...

reasoning Reason is the capacity of consciously applying logic by drawing conclusions from new or existing information, with the aim of seeking the truth. It is closely associated with such characteristically human activities as philosophy, science, langu ...

; and

quantum mechanics Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, ...

. In 1951, he authored '' The Rise of Scientific Philosophy'', his most popular book.

Early life

Hans was the second son of a

Jewish Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...

merchant, Bruno Reichenbach, who had converted to

Protestantism Protestantism is a Christian denomination, branch of Christianity that follows the theological tenets of the Reformation, Protestant Reformation, a movement that began seeking to reform the Catholic Church from within in the 16th century agai ...

. He married Selma Menzel, a school mistress, who came from a long line of Protestant professionals which went back to the

Reformation The Reformation (alternatively named the Protestant Reformation or the European Reformation) was a major movement within Western Christianity in 16th-century Europe that posed a religious and political challenge to the Catholic Church and in ...

. His elder brother Bernard played a significant role in the left communist movement. His younger brother, Herman was a music educator. After completing secondary school in

Hamburg Hamburg (, ; nds, label=Hamburg German, Low Saxon, Hamborg ), officially the Free and Hanseatic City of Hamburg (german: Freie und Hansestadt Hamburg; nds, label=Low Saxon, Friee un Hansestadt Hamborg),. is the List of cities in Germany by popul ...

, Hans Reichenbach studied civil

engineering Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...

at the Hochschule für Technik Stuttgart, and

physics Physics is the natural science that studies matter, its 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 which ...

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

and

philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. ...

at various universities, including

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitu ...

Erlangen Erlangen (; East Franconian: ''Erlang'', Bavarian: ''Erlanga'') is a Middle Franconian city in Bavaria, Germany. It is the seat of the administrative district Erlangen-Höchstadt (former administrative district Erlangen), and with 116,062 inha ...

Göttingen Göttingen (, , ; nds, Chöttingen) is a university city in Lower Saxony, central Germany, the capital of the eponymous district. The River Leine runs through it. At the end of 2019, the population was 118,911. General information The ori ...

and

Munich Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the third-largest city in Germany, after Berlin and ...

. Among his teachers were Ernst Cassirer,

, Max Planck,

Max Born Max Born (; 11 December 1882 – 5 January 1970) was a German physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a ...

and

Arnold Sommerfeld Arnold Johannes Wilhelm Sommerfeld, (; 5 December 1868 – 26 April 1951) was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and mentored many students for the new era of theoretic ...

Political activism

Reichenbach was active in youth movements and student organizations. He joined the Freistudentenschaft in 1910. He attended the founding conference of the

Freideutsche Jugend The Freideutsche Jugend was an umbrella organisation established in Wilhelmine Germany that set out to create an autonomous youth culture free of adult supervision. It was part of the broader German youth movement, emerging from the Wandervogel ...

umbrella group at Hoher Meissner in 1913. He published articles about the university reform, the freedom of research, and against

anti-Semitic Antisemitism (also spelled anti-semitism or anti-Semitism) is hostility to, prejudice towards, or discrimination against Jews. A person who holds such positions is called an antisemite. Antisemitism is considered to be a form of racism. Antis ...

infiltrations in student organizations. His older brother Bernard shared in this activism and went on to become a member of the

Communist Workers' Party of Germany The Communist Workers' Party of Germany (german: Kommunistische Arbeiter-Partei Deutschlands; KAPD) was an anti-parliamentarian and left communist party that was active in Germany during the time of the Weimar Republic. It was founded in April ...

, representing this organisation on the

Executive Committee of the Communist International The Executive Committee of the Communist International, commonly known by its acronym, ECCI (Russian acronym ИККИ), was the governing authority of the Comintern between the World Congresses of that body. The ECCI was established by the Founding ...

. Hans wrote the Platform of the Socialist Student Party, Berlin which was published in 1918. The party had remained clandestine until the November Revolution when it was formally founded with him as Chairman. He also worked with Karl Wittfogel,

Alexander Schwab Alexander Schwab (5 July 1887 – 12 November 1943) was a German political activist. He withdrew from active participation in politics after resigning from the fractious and short-lived Communist Workers' Party of Germany, Communist Workers' Part ...

and his other brother Herman at this time. In 1919 his text ''Student und Sozialismus : mit einem Anhang: Programm der Sozialistischen Studentenpartei'' was published by

Hermann Schüller Hermann Schüller (1893–1948) was a German writer and Communist activist. He was one of the founders of the League for Proletarian Culture in 1919. In October 1920, with Erwin Piscator he founded the Proletarian Theatre, Stage of the Revolution ...

, an activist with the League for Proletarian Culture. However following his attending lectures by Albert Einstein in 1919, he stopped participating in political groups.

Academic career

Reichenbach received a degree in

from the University of Erlangen in 1915 and his

PhD dissertation A thesis ( : theses), or dissertation (abbreviated diss.), is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings.International Standard ISO 7144 ...

on the theory of probability, titled ''Der Begriff der Wahrscheinlichkeit für die mathematische Darstellung der Wirklichkeit'' (''The Concept of Probability for the Mathematical Representation of Reality'') and supervised by Paul Hensel and Max Noether, was published in 1916. Reichenbach served during

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

on the Russian front, in the German army radio troops. In 1917 he was removed from active duty, due to an illness, and returned in

. While working as a physicist and engineer, Reichenbach attended

Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theor ...

's lectures on the

theory of relativity The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in ...

from 1917 to 1920. In 1920 Reichenbach began teaching at the Technische Hochschule Stuttgart as ''

Privatdozent ''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualific ...

''. In the same year, he published his first book (which was accepted as his

habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including ...

in physics at the Technische Hochschule Stuttgart) on the philosophical implications of the

, ''The Theory of Relativity and A Priori Knowledge'' (''Relativitätstheorie und Erkenntnis Apriori''), which criticized the Kantian notion of

synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to: Science * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic ...

a priori ("from the earlier") and ("from the later") are Latin phrases used in philosophy to distinguish types of knowledge, justification, or argument by their reliance on empirical evidence or experience. knowledge is independent from current ex ...

''. He subsequently published ''Axiomatization of the Theory of Relativity'' (1924), ''From Copernicus to Einstein'' (1927) and ''The Philosophy of Space and Time'' (1928), the last stating the logical positivist view on the theory of relativity. In 1926, with the help of Albert Einstein, Max Planck and

Max von Laue Max Theodor Felix von Laue (; 9 October 1879 – 24 April 1960) was a German physicist who received the Nobel Prize in Physics in 1914 for his discovery of the diffraction of X-rays by crystals. In addition to his scientific endeavors with con ...

, Reichenbach became assistant professor in the physics department of the University of Berlin. He gained notice for his methods of teaching, as he was easily approached and his courses were open to discussion and debate. This was highly unusual at the time, although the practice is nowadays a common one. In 1928, Reichenbach founded the so-called " Berlin Circle" (german: Die Gesellschaft für empirische Philosophie; en, Society for Empirical Philosophy). Among its members were

, David Hilbert and Kurt Grelling. The Vienna Circle manifesto lists 30 of Reichenbach's publications in a bibliography of closely related authors. In 1930 he and

began editing the journal '' Erkenntnis''. When

Adolf Hitler Adolf Hitler (; 20 April 188930 April 1945) was an Austrian-born German politician who was dictator of Germany from 1933 until his death in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor in 1933 and the ...

became

Chancellor of Germany The chancellor of Germany, officially the federal chancellor of the Federal Republic of Germany,; often shortened to ''Bundeskanzler''/''Bundeskanzlerin'', / is the head of the federal government of Germany and the commander in chief of the Ge ...

in 1933, Reichenbach was immediately dismissed from his appointment at the University of Berlin under the government's so called "Race Laws" due to his Jewish ancestry. Reichenbach himself did not practise Judaism, and his mother was a German Protestant, but he nevertheless suffered problems. He thereupon emigrated to

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...

, where he headed the Department of Philosophy at

Istanbul University , image = Istanbul_University_logo.svg , image_size = 200px , latin_name = Universitas Istanbulensis , motto = tr, Tarihten Geleceğe Bilim Köprüsü , mottoeng = Science Bridge from Past to the Future , established = 1453 1846 1933 ...

. He introduced

interdisciplinary Interdisciplinarity or interdisciplinary studies involves the combination of multiple academic disciplines into one activity (e.g., a research project). It draws knowledge from several other fields like sociology, anthropology, psychology, ec ...

seminars and courses on scientific subjects, and in 1935 he published ''The Theory of Probability''. In 1938, with the help of Charles W. Morris, Reichenbach moved to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

to take up a professorship at the

University of California, Los Angeles The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the Californ ...

in its Philosophy Department. Reichenbach helped establish UCLA as a leading philosophy department in the United States in the post-war period.

Carl 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 empiricism, a 20th-century movement in the philosophy of science. He is espe ...

Hilary Putnam Hilary Whitehall Putnam (; July 31, 1926 – March 13, 2016) was an American philosopher, mathematician, and computer scientist, and a major figure in analytic philosophy in the second half of the 20th century. He made significant contributions ...

, and Wesley Salmon were perhaps his most prominent students. During his time there, he published several of his most notable books, including ''Philosophic Foundations of Quantum Mechanics'' in 1944, ''Elements of Symbolic Logic'' in 1947, and '' The Rise of Scientific Philosophy'' (his most popular book) in 1951.MacTutor History of Mathematics archive
/ref> Reichenbach died unexpectedly of a heart attack on April 9, 1953. He was living in Los Angeles at the time, and had been working on problems in the

philosophy of time Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. S ...

and on the nature of

scientific law Scientific laws or laws of science are statements, based on repeated experiments or observations, that describe or predict a range of natural phenomena. The term ''law'' has diverse usage in many cases (approximate, accurate, broad, or narrow ...

s. As part of this he proposed a three part model of time in language, involving speech time, event time and — critically — reference time, which has been used by linguists since for describing tenses. This work resulted in two books published posthumously: ''The Direction of Time'' and ''Nomological Statements and Admissible Operations''.

Selected publications

*1916. ''Der Begriff der Wahrscheinlichkeit für die mathematische Darstellung der Wirklichkeit'' (Ph.D. dissertation, University of Erlangen). *1920. ''Relativitätstheorie und Erkenntnis Apriori'' (

thesis, Technische Hochschule Stuttgart). English translation: 1965. ''The theory of relativity and a priori knowledge''. University of California Press. *1922. "Der gegenwärtige Stand der Relativitätsdiskussion." English translation: "The present state of the discussion on relativity" in Reichenbach (1959). *1924. ''Axiomatik der relativistischen Raum-Zeit-Lehre''. English translation: 1969. ''Axiomatization of the theory of relativity''. University of California Press. *1924. "Die Bewegungslehre bei Newton, Leibniz und Huyghens." English translation: "The theory of motion according to Newton, Leibniz, and Huyghens" in Reichenbach (1959). *1927. ''Von Kopernikus bis Einstein. Der Wandel unseres Weltbildes''. English translation: 1942, ''From Copernicus to Einstein''. Alliance Book Co. *1928. ''Philosophie der Raum-Zeit-Lehre''. English translation: Maria Reichenbach, 1957, ''The Philosophy of Space and Time''. Dover. *1930. ''Atom und Kosmos. Das physikalische Weltbild der Gegenwart''. English translation: 1932, ''Atom and cosmos: the world of modern physics''. G. Allen & Unwin, ltd. *1931. "Ziele und Wege der heutigen Naturphilosophie." English translation: "Aims and methods of modern philosophy of nature" in Reichenbach (1959). *1935. ''Wahrscheinlichkeitslehre: eine Untersuchung über die logischen und mathematischen Grundlagen der Wahrscheinlichkeitsrechnung''. English translation: 1949, ''The theory of probability, an inquiry into the logical and mathematical foundations of the calculus of probability''. University of California Press. *1938.
Experience and prediction: an analysis of the foundations and the structure of knowledge
'.

University of Chicago Press The University of Chicago Press is the largest and one of the oldest university presses in the United States. It is operated by the University of Chicago and publishes a wide variety of academic titles, including '' The Chicago Manual of Style' ...

. *1942. ''From Copernicus to Einstein''. Dover 1980: *1944. ''Philosophic Foundations of Quantum Mechanics''. University of California Press. Dover 1998: *1947. ''Elements of Symbolic Logic''. Dover 1980: *1948. "Philosophy and physics" in ''Faculty research lectures, 1946''. University of California Press. *1949. "The philosophical significance of the theory of relativity" in Schilpp, P. A., ed., ''Albert Einstein: philosopher-scientist''. Evanston: The Library of Living Philosophers. *1951. ''The Rise of Scientific Philosophy''.

University of California Press The University of California Press, otherwise known as UC Press, is a publishing house associated with the University of California that engages in academic publishing. It was founded in 1893 to publish scholarly and scientific works by facul ...

. *1954. ''Nomological statements and admissible operations''. North Holland. *1956. ''The Direction of Time''. University of California Press. Dover 1971. *1959. ''Modern philosophy of science: Selected essays by Hans Reichenbach''. Routledge & Kegan Paul. Greenwood Press 1981: *1978. ''Selected writings, 1909–1953: with a selection of biographical and autobiographical sketches'' (Vienna circle collection). Dordrecht: Reidel. Springer paperback vol 1: *1979. ''Hans Reichenbach, logical empiricist'' (Synthese library). Dordrecht: Reidel. *1991. ''Erkenntnis Orientated: A Centennial volume for Rudolf Carnap and Hans Reichenbach''. Kluwer. Springer 2003: *1991. ''Logic, language, and the structure of scientific theories: proceedings of the Carnap-Reichenbach centennial'', University of Konstanz, 21–24 May 1991. University of Pittsburgh Press.

References

Sources

Adolf Grünbaum Adolf Grünbaum (; May 15, 1923 – November 15, 2018) was a German-American philosopher of science and a critic of psychoanalysis, as well as Karl Popper's philosophy of science. He was the first Andrew Mellon Professor of Philosophy at the Unive ...

, 1963, ''Philosophical Problems of Space and Time''. Alfred A. Knopf. Ch. 3. * Günther Sandner, ''The Berlin Group in the Making: Politics and Philosophy in the Early Works of Hans Reichenbach and Kurt Grelling''. Proceedings of 10th International Congress of the

International Society for the History of Philosophy of Science The International Society for the History of Philosophy of Science (HOPOS) is a philosophical organization for promoting the study of the history of philosophy of science. The society promotes exchange of ideas among scholars through meetings, jour ...

(HOPOS), Ghent, July 2014.
Abstract
) *

, 1991, ''Hans Reichenbach remembered'', ''Erkenntnis 35'': 5–10. * Wesley Salmon, 1977, "The philosophy of Hans Reichenbach," ''Synthese 34'': 5–88. * Wesley Salmon (ed.), 1979, ''Hans Reichenbach: Logical Empiricist''. Springer. * Wesley Salmon, 1991, "Hans Reichenbach's vindication of induction," ''Erkenntnis 35'': 99–122.

External links

*
''The Rise of Scientific Philosophy''
Descriptive summary & full searchable text at Google Book Search * *The Internet Encyclopedia of Philosophy

by Mauro Murzi. *The Stanford Encyclopedia of Philosophy
Hans Reichenbach
by Clark Glymour and Frederick Eberhardt. *The Stanford Encyclopedia of Philosophy:
Reichenbach's Common Cause Principle
by Frank Arntzenius.
Guide to the Hans Reichenbach Collection at the University of Pittsburgh's Archive of Scientific Philosophy"Reichenbach's Theory of Tense and its Application to English"
{{DEFAULTSORT:Reichenbach, Hans 1891 births 1953 deaths 20th-century American male writers 20th-century American philosophers 20th-century American physicists 20th-century educators 20th-century essayists 20th-century German male writers 20th-century German philosophers 20th-century German physicists American educators American logicians American male essayists American male non-fiction writers Jewish emigrants from Nazi Germany to the United States American physicists American socialists Analytic philosophers Empiricists Epistemologists German educators German logicians German male essayists German male non-fiction writers German physicists German socialists History of logic Humboldt University of Berlin faculty Istanbul University faculty Logical positivism Philosophers of education Philosophers of language Philosophers of logic Philosophers of mathematics Philosophers of time Philosophy academics Philosophy writers Probability theorists Quantum physicists UCLA Philosophy University of California, Los Angeles faculty Vienna Circle Writers from Hamburg