هانز رايخينباخ

الأعمال

• 1920نظرية النسبية والمعرفة القبلية (Relativitätstheorie und Erkenntnis apriori)

  نظرية النسبية ضد كانط: الفيزياء تحتاج مبادئ تنسّق الرياضيات مع التجربة، لكنها ليست ثابتة لكل الأزمنة.

• 1938التجربة والتنبؤ (Experience and Prediction)

  المعنى والمعرفة بدلالة الاحتمال، والتبرير البراغماتي للاستقراء، والفصل بين الاكتشاف والتبرير.

الموقف

Reichenbach began as a Kantian and used relativity against Kant. In 1920 he separated two meanings of the a priori: necessary and unrevisable, and constitutive of the object of knowledge. Physics needs principles that coordinate its mathematics with reality, but relativity had shown that such principles can change; so they are constitutive but revisable, and after Moritz Schlick’s criticism he soon called them conventions. In The Philosophy of Space and Time (1928) he argued that the geometry of physical space becomes an empirical question only once a coordinating definition, for instance of a rigid rod, has been fixed. He interpreted probability as the limit of relative frequency in a sequence of events and gave induction a pragmatic justification: if any method can find such limits, the simple inductive rule will, though it offers a “posit”, not a guarantee. Experience and Prediction (1938) made a distinction that became standard: philosophy of science reconstructs the context of justification and leaves the context of discovery to psychology. His analysis of tense by speech time, event time and reference time (1947) is still used in linguistics; The Direction of Time (1956) introduced the principle of the common cause. Karl Popper rejected any probabilistic logic of induction, and Reichenbach answered that falsification itself needs probabilities. Thomas Kuhn, Paul Feyerabend and the sociology of science later questioned whether discovery and justification can be separated so cleanly.

الحياة والسياق

Hans Reichenbach was born in Hamburg on 26 September 1891. He studied civil engineering in Stuttgart, then physics, mathematics and philosophy in Berlin, Munich and Göttingen; among his teachers were Ernst Cassirer, Max Planck, Arnold Sommerfeld and David Hilbert. He took his doctorate at Erlangen in 1915 with a thesis on probability. In Berlin he attended Albert Einstein’s lectures on relativity and became his friend. In 1920 he qualified as a lecturer at the Technische Hochschule Stuttgart with The Theory of Relativity and A Priori Knowledge. In 1926, with Einstein’s support, he was appointed to teach natural philosophy at the University of Berlin, where the Society for Empirical Philosophy became the centre of the “Berlin Group” with Kurt Grelling, Walter Dubislav and others; from 1930 he edited the journal Erkenntnis with Rudolf Carnap. Dismissed in 1933 under the Nazi laws, he taught at the new University of Istanbul until 1938, then at the University of California, Los Angeles. Carl Gustav Hempel studied with him in Berlin, Hilary Putnam and Wesley Salmon took their doctorates with him in Los Angeles. He died there on 9 April 1953.

أعمال رئيسة أخرى

• The Philosophy of Space and Time (Philosophie der Raum-Zeit-Lehre, 1928)
• The Theory of Probability (Wahrscheinlichkeitslehre, 1935)
• Philosophic Foundations of Quantum Mechanics (1944)
• Elements of Symbolic Logic (1947)
• The Rise of Scientific Philosophy (1951)
• The Direction of Time (posthumous, 1956)