In
logic, anti-psychologism (also logical objectivism or logical realism) is a
theory about the nature of
logical truth, that it does not depend upon the contents of human ideas but exists independent of human ideas.
Overview
The anti-psychologistic treatment of logic originated in the works of
Immanuel Kant and
Bernard Bolzano.
The concept of logical objectivism or anti-psychologism was further developed by
Johannes Rehmke (founder of
Greifswald objectivism
Johannes Rehmke (1 February 1848 – 23 December 1930) was a German philosopher and since 1885 professor at Greifswald University, later also provost of this university. He offered sharp criticisms of Immanuel Kant's approach to epistemology. In h ...
) and
Gottlob Frege (founder of
logicism the most famous anti-psychologist in the
philosophy of mathematics), and has been the centre of an important debate in early
phenomenology
Phenomenology may refer to:
Art
* Phenomenology (architecture), based on the experience of building materials and their sensory properties
Philosophy
* Phenomenology (philosophy), a branch of philosophy which studies subjective experiences and a ...
and
analytical philosophy. Frege's work was influenced by Bolzano.
Elements of anti-psychologism in the
historiography of philosophy
The history of science covers the development of science from ancient history, ancient times to the present. It encompasses all three major branches of science: natural science, natural, social science, social, and formal science, formal.
Sc ...
can be found in the work of the members of the 1830s
speculative theist
The Right Hegelians (german: Rechtshegelianer), Old Hegelians (''Althegelianer''), or the Hegelian Right (''die Hegelsche Rechte''), were those followers of German philosopher Georg Wilhelm Friedrich Hegel in the early 19th century who took his phi ...
movement and the late work of
Hermann Lotze.
The psychologism dispute (german: Psychologismusstreit) in 19th-century German-speaking philosophy is closely related to the contemporary
internalism and externalism debate in
epistemology;
psychologism is often construed as a kind of internalism (the thesis that no fact about the world can provide reasons for action independently of desires and beliefs) and anti-psychologism as a kind of externalism (the thesis that reasons are to be identified with objective features of the world).
Psychologism was defended by
Theodor Lipps,
Gerardus Heymans,
Wilhelm Wundt
Wilhelm Maximilian Wundt (; ; 16 August 1832 – 31 August 1920) was a German physiologist, philosopher, and professor, known today as one of the fathers of modern psychology. Wundt, who distinguished psychology as a science from philosophy and ...
,
Wilhelm Jerusalem,
Christoph von Sigwart,
Theodor Elsenhans, and
Benno Erdmann.
Edmund Husserl was another important proponent of anti-psychologism, and this trait passed on to other phenomenologists, such as
Martin Heidegger
Martin Heidegger (; ; 26 September 188926 May 1976) was a German philosopher who is best known for contributions to phenomenology, hermeneutics, and existentialism. He is among the most important and influential philosophers of the 20th centur ...
, whose doctoral thesis was meant to be a refutation of psychologism. They shared the argument that, because the proposition "no-p is a not-p" is not
logically equivalent to "It is thought that 'no-p is a not-p'", psychologism does not logically stand.
Charles Sanders Peirce—whose fields included logic, philosophy, and experimental psychology—could also be considered a critic of psychologism in logic.
The return of psychologism
Psychologism is not widely held amongst logicians today, but something like it has some high-profile defenders especially among those who do research at the intersection of logic and
cognitive science, for example
Dov Gabbay and
John Woods, who concluded that "whereas mathematical logic must eschew psychologism, the new logic cannot do without it".
[ See also: ]
Notes
{{reflist
Further reading
* Vladimir Bryushinkin
Metapsychologism in the Philosophy of Logic ''Proc. Logic and Philosophy of Logic'', 20th World Congress in Philosophy, 2000.
* Martin Kusch. ''Psychologism: A Case Study in the Sociology of Philosophical Knowledge''. London and New York: Routledge, 1995.
Theories of deduction