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Moritz Schlick

1882–1936

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A statement is meaningful only if we can say how to check it – so claims that cannot be tested in any way say nothing.

Placement

Analytic Philosophy · Western Europe · Science, Epistemology

Founder of the Vienna Circle: the meaning of a proposition is the method of its verification.

Key ideas

  • Vienna Circle
  • Verificationism

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Influence

Influenced by 3

  • Ernst Mach

    influenced by

    Schlick took Mach’s former Vienna chair (1922) and chaired the Verein Ernst Mach (1928), though his early critical realism had rejected Mach’s positivism (Allgemeine Erkenntnislehre, 1918). M. Schlick, Allgemeine Erkenntnislehre (1918); SEP “Moritz Schlick”; SEP “Vienna Circle”

    Evidence: also in InPhO · InPhO

    Ernst Mach › 1838–1916

  • Albert Einstein

    influenced by

    Schlick gave an early philosophical account of relativity, welcomed by Einstein (Raum und Zeit in der gegenwärtigen Physik, 1917), and built his theory of knowledge on it (1918). M. Schlick, Raum und Zeit in der gegenwärtigen Physik (1917); Allgemeine Erkenntnislehre (1918); SEP “Moritz Schlick”

    Evidence: AI draft

    Albert Einstein › 1879–1955

  • Ludwig Wittgenstein

    influenced by

    Schlick saw in the Tractatus the turning point of philosophy, now an activity of clarifying meaning, not a science (‘Die Wende der Philosophie’, 1930); they met from 1927. M. Schlick, “Die Wende der Philosophie”, Erkenntnis 1 (1930); F. Waismann, Wittgenstein und der Wiener Kreis (ed. B. McGuinness, 1967); SEP “Moritz Schlick”

    Evidence: also in InPhO · InPhO

    Ludwig Wittgenstein › 1889–1951

Influenced 3

  • Kurt Gödel

    influenced

    Gödel attended Schlick’s seminar on Russell’s Introduction to Mathematical Philosophy and, from 1926, meetings of the Vienna Circle, without adopting its positivism. J. W. Dawson, Logical Dilemmas: The Life and Work of Kurt Gödel (1997); SEP “Kurt Gödel”

    Evidence: AI draft

    Kurt Gödel › 1906–1978

  • A. J. Ayer

    influenced

    Ayer, sent to Vienna by Ryle, attended meetings of Schlick’s circle (1932–33) and brought its verification principle and rejection of metaphysics to Britain (Language, Truth and Logic, 1936). A. J. Ayer, Language, Truth and Logic (1936); Part of My Life (1977); M. Schlick, “Meaning and Verification”, Philosophical Review 45 (1936); SEP “Alfred Jules Ayer”

    Evidence: AI draft

    A. J. Ayer › 1910–1989

  • Arne Næss

    influenced

    Næss took part in Schlick’s circle in Vienna (1934–35) and turned its empiricism into an empirical semantics, testing views of truth by questionnaires among non-philosophers (1938). A. Næss, Erkenntnis und wissenschaftliches Verhalten (1936); “Truth” as Conceived by Those Who Are Not Professional Philosophers (1938)

    Evidence: AI draft

    Arne Næss › 1912–2009

Criticism

Criticized by 1

  • Otto Neurath

    criticised by

    Neurath rejected Schlick’s ‘affirmations’ as an unshakeable foundation of knowledge: all statements, protocol sentences included, remain revisable (‘Radikaler Physikalismus und „wirkliche Welt“’, 1934). O. Neurath, “Radikaler Physikalismus und »wirkliche Welt«”, Erkenntnis 4 (1934); M. Schlick, “Über das Fundament der Erkenntnis”, Erkenntnis 4 (1934); O. Neurath, “Protokollsätze”, Erkenntnis 3 (1932/33)

    Evidence: AI draft

    Otto Neurath › 1882–1945

Works

Position

Schlick wanted philosophy to learn from the revolution in physics, above all from Einstein’s relativity, which he was among the first to interpret philosophically. Knowledge, he argued, is not a mirror of things but a coordination of signs with reality. In the Vienna years he defended the principle that the meaning of a statement lies in the method of its verification: what no possible experience could ever confirm or refute says nothing at all. Philosophy thus becomes not a body of doctrines but an activity of clarifying meaning, while the sciences establish truths. This program shaped logical empiricism and, through Carnap and others, analytic philosophy in the English-speaking world.

Life & context

Born in Berlin in 1882, Schlick earned his doctorate in physics under Max Planck before turning to philosophy. After posts in Rostock and Kiel he took the chair of natural philosophy in Vienna in 1922, where a discussion group of philosophers, mathematicians and scientists formed around him: the Vienna Circle. In 1936 he was shot dead on the university steps by a former student.

Further main works

  • Space and Time in Contemporary Physics (1917)
  • General Theory of Knowledge (1918)
  • Problems of Ethics (1930)

Sources: Wikipedia · Wikidata

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