Jan Łukasiewicz

Jan Leopold Łukasiewicz (; 21 December 1878 – 13 February 1956) was a Polish logician, and philosopher who is best known for Polish notation and Łukasiewicz logic. on 21 December 1878 in Lemberg, Austria-Hungary (now Lviv, Ukraine) and was the only child of Paweł Łukasiewicz, a captain in the Austro-Hungarian Army, and Leopoldina, née Holtzer, the daughter of a civil servant. His family was Roman Catholic.

He finished his gymnasium studies in philology and in 1897 went on to Lemberg University, where he studied philosophy and mathematics. He was a pupil of the philosopher Kazimierz Twardowski.

He spent three years as a private teacher, and in 1905, he received a scholarship to complete his philosophy studies at the University of Berlin and the University of Louvain in Belgium.

From October to December 2022, the Royal Irish Academy in Dublin hosted an exhibition on his life and work.

Łukasiewicz's papers (post-1945) are held by the University of Manchester Library.

Work A number of axiomatizations of classical propositional logic are due to Łukasiewicz. A particularly elegant axiomatization features a mere three axioms and is still invoked 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, and 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. A quotation from a paper by Jan Łukasiewicz in 1931 states how the notation was invented:

The reference cited by Łukasiewicz, i.e., Łukasiewicz (1), is apparently a lithographed report in Polish. The referring paper by Łukasiewicz was reviewed by Henry A. Pogorzelski in the Journal of Symbolic Logic in 1965.

In 1935, Łukasiewicz was awarded the Hungarian Order of Merit.

In 1955, Łukasiewicz received an honorary doctorate from the Trinity College Dublin in acknowledgement of his academic achievements. A commemorative plaque has been unveiled on the house where Łukasiewicz lived in Dublin at 57 Fitzwilliam Square.

In 1998, a minor planet discovered by Paul G. Comba was named 27114 Lukasiewicz in honour of the Polish philosopher and logician.

In 2008, the Polish Information Processing Society established the Jan Łukasiewicz Award, to be presented to the most innovative Polish IT companies.

His model of three-valued logic allowed for formulating Kleene's ternary logic and a meta-model of empiricism, mathematics and logic, i.e. senary logic.