Georg Kreisel FRS (September 15, 1923 – March 1, 2015) was an

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

n-born

mathematical logic Mathematical logic is the study of Logic#Formal logic, formal logic within mathematics. Major subareas include model theory, proof theory, set theory, and recursion theory (also known as computability theory). Research in mathematical logic com ...

ian who studied and worked in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

and

America The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Biography

Kreisel was born in

Graz Graz () is the capital of the Austrian Federal states of Austria, federal state of Styria and the List of cities and towns in Austria, second-largest city in Austria, after Vienna. On 1 January 2025, Graz had a population of 306,068 (343,461 inc ...

and came from a

Jew Jews (, , ), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of ancient Israel and Judah. They also traditionally adhere to Judaism. Jewish ethnicity, religion, and community are highly inte ...

ish background; his family sent him to the

before the

Anschluss The (, or , ), also known as the (, ), was the annexation of the Federal State of Austria into Nazi Germany on 12 March 1938. The idea of an (a united Austria and Germany that would form a "German Question, Greater Germany") arose after t ...

in 1938. He studied mathematics at

Trinity College, Cambridge Trinity College is a Colleges of the University of Cambridge, constituent college of the University of Cambridge. Founded in 1546 by King Henry VIII, Trinity is one of the largest Cambridge colleges, with the largest financial endowment of any ...

, and then, during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, worked on

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. Militaries are typically authorized and maintained by a sovereign state, with their members identifiable by a d ...

subjects. Kreisel never took a Ph.D., though much later, in 1962, he was awarded the Cambridge degree of

Sc.D. A Doctor of Science (; most commonly abbreviated DSc or ScD) is a science doctorate awarded in a number of countries throughout the world. Africa Algeria and Morocco In Algeria, Morocco, Libya and Tunisia, all universities accredited by the s ...

, a 'higher doctorate' given on the basis of published research. He taught at the

University of Reading The University of Reading is a public research university in Reading, Berkshire, England. It was founded in 1892 as the University Extension College, Reading, an extension college of Christchurch College, Oxford, and became University College, ...

from 1949 until 1954 and then worked at the

Institute for Advanced Study The Institute for Advanced Study (IAS) is an independent center for theoretical research and intellectual inquiry located in Princeton, New Jersey. It has served as the academic home of internationally preeminent scholars, including Albert Ein ...

from 1955 to 1957. He returned to Reading in 1957, but then taught at

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

from 1958–1959. Then back at Reading for the year 1959–1960, and then the

University of Paris The University of Paris (), known Metonymy, metonymically as the Sorbonne (), was the leading university in Paris, France, from 1150 to 1970, except for 1793–1806 during the French Revolution. Emerging around 1150 as a corporation associated wit ...

1960–1962. Kreisel was appointed a professor at

in 1962 and remained on the faculty there until he retired in 1985. Kreisel worked in various areas of logic, and especially in

proof theory Proof theory is a major branchAccording to , proof theory is one of four domains mathematical logic, together with model theory, axiomatic set theory, and recursion theory. consists of four corresponding parts, with part D being about "Proof The ...

, where he is known for his so-called " unwinding" program, whose aim was to extract constructive content from superficially non-constructive

proof Proof most often refers to: * Proof (truth), argument or sufficient evidence for the truth of a proposition * Alcohol proof, a measure of an alcoholic drink's strength Proof may also refer to: Mathematics and formal logic * Formal proof, a co ...

s. Kreisel was elected to the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

in 1966; Kreisel remained a close friend of

Francis Crick Francis Harry Compton Crick (8 June 1916 – 28 July 2004) was an English molecular biologist, biophysicist, and neuroscientist. He, James Watson, Rosalind Franklin, and Maurice Wilkins played crucial roles in deciphering the Nucleic acid doub ...

whom he had met in the Royal Navy during WWII. While a student at Cambridge, Kreisel was the student most respected by

Ludwig Wittgenstein Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language. From 1929 to 1947, Witt ...

. Ray Monk writes, "In 1944—when Kreisel was still only twenty-one—Wittgenstein shocked

Rush Rhees Rush Rhees (; 19 March 1905 – 22 May 1989) was an American philosopher. He is principally known as a student, friend, and literary executor of the philosopher Ludwig Wittgenstein. With G. E. M. Anscombe he was co-editor of Wittgenstein's posth ...

by declaring Kreisel to be the most able philosopher he had ever met who was also a mathematician." Kreisel was also a close friend of the Anglo-Irish philosopher and novelist

Iris Murdoch Dame Jean Iris Murdoch ( ; 15 July 1919 – 8 February 1999) was an Irish and British novelist and philosopher. Murdoch is best known for her novels about good and evil, sexual relationships, morality, and the power of the unconscious. Her fi ...

. They met at Cambridge in 1947 during Murdoch's year of study there. Peter Conradi reports that Murdoch transcribed Kreisel's letters into her journals over the next fifty years. According to Conradi, "For half a century she nonetheless records variously Kreisel's brilliance, wit and sheer 'dotty' solipsistic strangeness, his amoralism, cruelty, ambiguous vanity and obscenity." Murdoch dedicated her 1971 novel '' An Accidental Man'' to Kreisel and he became a (partial) model for several characters in other novels, including Marcus Vallar in '' The Message to the Planet'' and Guy Openshaw in '' Nuns and Soldiers''. After retirement Kreisel lived in

Salzburg Salzburg is the List of cities and towns in Austria, fourth-largest city in Austria. In 2020 its population was 156,852. The city lies on the Salzach, Salzach River, near the border with Germany and at the foot of the Austrian Alps, Alps moun ...

, Austria. He wrote several biographies of mathematicians including

Kurt Gödel Kurt Friedrich Gödel ( ; ; April 28, 1906 – January 14, 1978) was a logician, mathematician, and philosopher. Considered along with Aristotle and Gottlob Frege to be one of the most significant logicians in history, Gödel profoundly ...

Bertrand Russell Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British philosopher, logician, mathematician, and public intellectual. He had influence on mathematics, logic, set theory, and various areas of analytic ...

and

Luitzen Egbertus Jan Brouwer Luitzen Egbertus Jan "Bertus" Brouwer (27 February 1881 – 2 December 1966) was a Dutch mathematician and philosopher who worked in topology, set theory, measure theory and complex analysis. Regarded as one of the greatest mathematicians of the ...

. He died in Salzburg, aged 91.

Anecdotes

When Kreisel was teaching at the

he would frequently take the train into London. There was a particularly fast train that was timed just right for the shows in London, and he would go to the station at that time. He checked the timetable one day, and that train was canceled. But out of habit one day he showed up at the station at the usual time and the train was there. It seems that it was going from

Bristol Bristol () is a City status in the United Kingdom, cathedral city, unitary authority area and ceremonial county in South West England, the most populous city in the region. Built around the River Avon, Bristol, River Avon, it is bordered by t ...

to London, stopping at Reading only to get water. He got on the train anyway, and from then on took that train regularly. One day he was accosted by the conductor after he got on. "The train doesn't stop here sir!" "In that case I didn't get on here."''Kreiseliana: About and Around Georg Kreisel'', ed. by Piergiorgio Odifreddi, Wellesley, MA, 1996, (Festschrift)

References

External links

* Piergiorgio Odifreddi (ed.), ''Kreiseliana: About and Around George Kreisel'', Wellesley, Massachusetts: A. K. Peters, 1996. . * tp://ftp.cs.ru.nl/pub/CompMath.Found/kr.ps Kreisel, lambda calculus, a windmill and a castleContains personal recollections about Kreisel by his student Henk Barendregt. * {{DEFAULTSORT:Kreisel, Georg 1923 births Austrian mathematicians 20th-century British mathematicians 21st-century British mathematicians Proof theorists Cambridge University Moral Sciences Club Austrian logicians 20th-century American mathematicians 21st-century American mathematicians Fellows of the Royal Society 2015 deaths Austrian emigrants to the United Kingdom British emigrants to the United States

Biography

Anecdotes

See also

References

External links