Jan Łukasiewicz

Jan Łukasiewicz (21 December, 1878 – 13 February, 1956) was a Polish mathematician born in Lemberg, Galicia, Austria-Hungary (now Lviv, Ukraine). His major mathematical work centred on mathematical logic. He thought innovatively about traditional propositional logic, the principle of non-contradiction and the law of excluded middle.

Life and work

To Łukasiewicz we owe a number of axiomatizations of classical propositional logic. A particularly elegant axiomatization features a mere three axioms and is still invoked down to the present day. He was a pioneer investigator of multi-valued logics; his three-valued propositional calculus, introduced in 1917, was the first explicitly axiomatized non-classical logical calculus. He wrote on the philosophy of science. His approach to the making of scientific theories was similar to the thinking of Karl Popper.

Łukasiewicz invented the Polish notation (named after his nationality) for the logical connectives around 1920. This notation is the root of the idea of the recursive stack, a last-in, first-out computer memory store proposed by several researchers including Turing, Bauer and Hamblin, and first implemented in 1957. This design led to the English Electric multi-programmed KDF9 computer system of 1963, which had two such hardware register stacks. A similar concept underlies the reverse Polish notation (RPN, a postfix notation) of the Friden EC-130 calculator and its successors, many Hewlett Packard calculators, the Forth programming language, or the PostScript page description language.

Łukasiewicz was a devout Roman Catholic. During the occupation of Poland in WW2 he worked in the secret Warsaw Underground University (Tajny Uniwersytet Warszawski). At the end of the war he was living in Hembsen, where he had been brought for his own safety.

Chronology

• 1878 Born
• 1890-1902 Studies with Kazimierz Twardowski in Lemberg (Lwów, L'viv)
• 1902 Doctorate (mathematics and philosophy), University of Lemberg with the highest distinction possible
• 1906 Habilitation thesis completed, University of Lemberg (Lwów, L'viv)
• 1906 Becomes a lecturer
• 1910 essays on the principle of non-contradiction and the excluded middle
• 1911 extraordinary professor at Lemberg (Lwów, L'viv)
• 1915 invited to the newly reopened University of Warsaw
• 1916 new Kingdom of Poland declared
• 1917 Develops three-valued propositional calculus
• 1919 Polish Minister of Education
• 1920-1939 professor at Warsaw University founds with Stanisław Leśniewski the Lwów-Warsaw School of logic (see also Alfred Tarski, Stefan Banach, Hugo Steinhaus, Zygmunt Janiszewski, Stefan Mazurkiewicz)
• 1928 marries Regina Barwińska
• 1946 exile in Belgium
• 1946 offered a chair by the University College Dublin
• 1953 writes autobiography
• 1956 Dies in Dublin

See also

• 27114 Lukasiewicz
• History of philosophy in Poland
• Łukasiewicz logic

Further reading

• Łukasiewicz, Jan (1957). Aristotle’s Syllogistic from the Standpoint of Modern Formal Logic. Oxford University Press. Reprinted by Garland Publishing in 1987. ISBN 0824069242
• Łukasiewicz, Jan (1958). Elementy logiki matematycznej.. Warsaw, Państwowe Wydawnictwo Naukowe.
• Łukasiewicz, Jan (1964). Elements of Mathematical Logic. Translated from Polish by Olgierd Wojtasiewicz.. New York, Macmillan.
• Łukasiewicz, Jan (1970). Selected Works. North-Holland Pub. Co..
• Seddon, Frederick (1996). Aristotle & Łukasiewicz on the Principle of Contradiction. Ames, Iowa: Modern Logic Pub..
• Wolenski, Jan (1994). Philosophical Logic in Poland. Kluwer Academic Publishers.

External links

• Polish Philosophy Page: Jan Łukasiewicz