Jacob Klein (philosopher)

Jacob Klein (born March 3, 1899 in Liepāja , Russian Empire , today Latvia , † July 16, 1978 in Annapolis , Maryland , United States ) was a German-American philosopher and mathematician of Jewish descent.

life and work

Klein grew up in Russia (which Latvia was then part of), Belgium, and Germany. From 1917 he studied mathematics and physics in Berlin for three years and then wanted to study philosophy with Edmund Husserl in Freiburg (and he was strongly influenced by him), but he advised him to study philosophy in Marburg. In 1922 he did his doctorate under Nicolai Hartmann with a dissertation on the relationship between logical and historical considerations in Hegel. He then studied with Martin Heidegger and was also a theoretical physicist at Berlin University. Then he was a private lecturer in Marburg, went to Prague after the Nazis came to power in 1933 and then went to the USA via Berlin and England. From 1937 he taught at St. John's College in Annapolis, Maryland. Here he held the position of dean from 1949 to 1958 . His teaching activities at this college (a liberal arts college that had joined the "Great Book" program) lasted until his death. His close friendship with the philosopher Leo Strauss is of particular importance .

Jacob Klein's most important work is the study: The Greek Logistics and the Origin of Algebra ( Greek Mathematical Thought and the Origin of Algebra ), in which he examines the development from ancient mathematics to modern, with special attention to the respective understanding of numbers . The central thesis is that the modern understanding of mathematics is based on a symbolic interpretation of the Greek number concept ( arithmos ). In it, he also criticizes Husserl's number concept (Hopkins), but in particular the theory that was common at the time and that was widespread in books by Otto Neugebauer and Bartel Leendert van der Waerden (which goes back to Hieronymus Zeuthen ) that the Greeks used a geometric form of algebra and thereby used their algebraic form Concepts adopted from the Babylonians, but after the Pythagoreans discovered irrationality, they put them into geometric form. Klein's approach was instead through Greek philosophy, and his criticism was later resumed by others ( Árpád Szabó , Sabetai Unguru ) who considered the concept of a Greek geometric algebra, which came from mathematically trained mathematicians, to be unhistorical. According to Klein, on the other hand, the representation of numbers, for example in Euclid's elements, was always associated with concrete objects and the abstraction of the number concept for algebra took place in the Platonic and Neoplatonic philosophy ( theoretical logistics in Plato as the abstraction of the number concept of counting , compared to arithmetic, the the relationships between numbers are considered), by Diophant (whom Klein interprets as a representative of theoretical logistics ) and by Diophant to the further development of algebra by the Arabs and Francois Viète .

He also published commentaries and studies on various Platonic dialogues and other topics of ancient philosophy .

Fonts

• Greek logistics and the origin of algebra. In: Sources and studies on the history of mathematics, astronomy and physics. Department B: Studies. Volume 3, First Issue, Berlin 1934, pp. 18-105 and Second Issue, Berlin 1936, pp. 122-235. Republished in English under the title: Greek Mathematical Thought and the Origin of Algebra. Cambridge, Mass. 1968, ISBN 0-486-27289-3 .
• Phenomenology and Science. In: Philosophical Essays in Memory of Edmund Husserl. Cambridge, Mass. 1940, ISBN 0-8371-0071-2 .
• A Commentary on Plato's Meno. Chapel Hill 1965, ISBN 0-226-43959-3 .
• Plato's trilogy. Theaetetus, the Sophist and the Statesman. Chicago 1977, ISBN 0-226-43951-8 .
• Lectures and Essays. Annapolis, Maryland 1985, ISBN 0-9603690-2-3 .
• Correspondence between Jacob Klein and Leo Strauss in: Leo Strauss: Gesammelte Schriften. Volume 3: Hobbes' Political Science and Related Writings - Letters. Edited by Heinrich Meier. Stuttgart, Weimar 2001, pp. 455-605, ISBN 3-476-01213-1 .

literature

• Burt C. Hopkins: The Origin of the Logic of Symbolic Mathematics: Edmund Husserl and Jacob Klein , Indiana University Press, 2011, ISBN 978-0-253-35671-0 .
• Burt C. Hopkins: The philosophical achievement of Jacob Klein , in: New Yearbook of Phenomenology and Phenomenological Philosophy, Volume 11, 2011, pp. 282-296
• Philipp Lenhard: A Greek yeshiva on the Chesapeake Bay: Leo Strauss, Jacob Klein and the ideal of friendship. In: Munich Contributions to Jewish History and Culture. 2/2015. Pp. 28-41.
• Martina Schneider: Contextualizing Unguru's 1975 attack on the historiography of ancient greek mathematics , in: Volker Remmert, Martina Schneider, Henrik Kragh Sörensen (eds.), Historiography of Mathematics in the 19th and 20th centuries, Birkhäuser 2016 pp. 251f

Web links

• Literature by and about Jacob Klein in the catalog of the German National Library