POLAK, LEONARD (1880–1941), Dutch philosopher. Born in Steenwijk, Polak graduated in law, in 1925 became assistant professor at the University of Leiden, and in 1929 was appointed to the chair in philosophy at the University of Groningen. A rationalist and agnostic, Polak played an important part in the free-thought movement in the Netherlands. He followed the Marburg neo-Kantian school of philosophy holding that mechanical causality reigns in nature while freedom reigns in the realm of the spirit.
Polak wrote on important social questions such as the philosophy of war, the philosophy of punishment, sexual ethics, and religious divisions. His principal works include Kennisleer contra materie-realisme (1912); De zin der vergelding (1921); Hegel's leer der straf (1925); and Noodlot en vrije wil (1937). After World War ii, Polak's works were collected in Verzamelde werken (4 vols, 1947).
P. Spigt, Leo Polak, een erflater van onze beschaving (1946); L. van der Wal, Herdenking van Leo Polak (1946); F. Sassen, Wijsgerig leven in Nederland in de twintigste eeuw (19482).
[Richard H. Popkin]