Stanislaw Lesniewski

Stanislaw Lesniewski lived from March 30, 1886, born in Serpukhov in the Russian Empire, to May 13, 1939, and was a Polish mathematician, philosopher and logician who taught at the University of Warsaw. A leading figure of the Lwow-Warsaw school of logic, he is known for coining and introducing the concept of mereology, the formal study of parts and wholes, as part of a wider framework built from three nested formal systems he called protothetic, ontology and mereology. Working alongside Jan Lukasiewicz and Alfred Tarski at the University of Warsaw during the interwar period, he helped make it one of the most important centers in the world for formal logic. A radical nominalist, he rejected axiomatic set theory and built his systems as an alternative logical foundation for mathematics.