Polish philosopher, historian of ideas, naturalist. His studies of medicine in Kiev were interrupted by his arrest and deportation to Siberia. After returning from exile, he received a degree in botany at the university of Tartu in 1890, followed by a doctoral degree in philosophy at the University of Krakow in 1900 (where he also studied organic chemistry), and a habilitation in philosophy in Lviv. Moved to Geneva in 1902, where he taught as a private docent. Returned to Poland in 1920 (Poznan, Warsaw), where he edited the series « Fundamentals of Modern Education » and adhered to the progressive-democratic party. He is the author of numerous works on the history of philosophy, sociology and the theory and methodology of science.