Background
Gerhard Gentzen was born on November 24, 1909, in Greifswald, Germany.
Gerhard Gentzen
Wilhelmsplatz 1, 37073 Göttingen, Germany
Gentzen studied at the University of Göttingen, where he benefited from the teaching of such renowned scholars as P. Bernays, C. Carathéodory, R. Courant, D. Hilbert. At the age of twenty-three, he received his doctorate in mathematics.
Wilhelmsplatz 1, 37073 Göttingen, Germany
Gentzen studied at the University of Göttingen, where he benefited from the teaching of such renowned scholars as P. Bernays, C. Carathéodory, R. Courant, D. Hilbert. At the age of twenty-three, he received his doctorate in mathematics.
Germany
Gerhard playing table tennis
Germany
Gerhard at school
https://www.amazon.com/collected-Gerhard-Gentzen-foundations-mathematics/dp/072042254X
1969
educator logician mathematician scientist
Gerhard Gentzen was born on November 24, 1909, in Greifswald, Germany.
As a boy, Gentzen declared his dedication to mathematics. He studied at the University of Göttingen, where he benefited from the teaching of such renowned scholars as P. Bernays, C. Carathéodory, R. Courant, D. Hilbert. At the age of twenty-three, he received his doctorate in mathematics.
In 1934 Gentzen became one of Hilbert’s assistants and held that position until 1943, with the exception of a two-year period of compulsory military service from 1939 to 1941, when he was requested to take up a teaching post at the University of Prague. From 1943 he was a teacher at the University of Prague (today Charles University). Under a contract from the SS Gentzen evidently worked for the V-2 project. Gentzen was arrested during the citizens uprising against the occupying German forces on May 5, 1945. He, along with the rest of the staff of the German University in Prague was subsequently handed over to Russian forces. Because of his past association with the SA, NSDAP and NSD Dozentenbund, Gentzen was detained in a prison camp, where he died of malnutrition on August 4, 1945.
Gentzen's main work was on the foundations of mathematics, in proof theory, specifically natural deduction and the sequent calculus. His cut-elimination theorem is the cornerstone of proof-theoretic semantics, and some philosophical remarks in his "Investigations into Logical Deduction", together with Ludwig Wittgenstein's later work, constitute the starting point for inferential role semantics. Gentzen published his papers in the ideological Deutsche Mathematik that was founded by Ludwig Bieberbach.
Gentzen joined the Nazi Party in 1937. In April 1939 Gentzen swore the oath of loyalty to Adolf Hitler as part of his academic appointment.
Gentzen invented “natural deduction” in order to create a predicate logic more akin to actual mathematical reasoning than the Frege-Russell-Hilbert systems, then used P. Hertz’s “sentences” to transform his natural calculus, into a “calculus of Sequents." Thus he succeeded in making classical logic appear as a simple extension of intuitionist logic and in enunciating his chief theory, which he had discovered while studying more closely the specific properties of natural deduction. A formalization of elementary number theory based on sequents and his ingenious idea of using restricted transfinite induction as a metamathematical technique enabled Gentzen to carry out the first convincing consistency proof for elementary number theory, in spite of the limitations imposed on such proofs by Gödel’s theorem. He eventually proved directly the nonderivability in elementary number theory of the required transfinite induction.
Gentzen combined in rare measure an exceptional inventiveness and the talent for coordinating diverse existing knowledge into a systematic conceptual framework.
