Professor of Moscow University, 1901. Rector of Moscow University, 1908-1911. As a young scientist, interested in Marxism (translated Marx), then liberal populism, and later joined the Cadet Party.
Opponent of Stolypin’s agrarian policies. In the spring of 1917, Minister of Education in the Provisional Government. After the October Revolution 1917, emigrated, but soon returned.
Taught Marxism in various Russian universities.