"There are many reasons for writing a biography of Semyon Frank. Quite apart from his philosophy, he lived a remarkable life. Born in Moscow in 1877, he was exiled from Soviet Russia in 1922 and died in London in 1950. The son of a Jewish doctor, he became a revolutionary Social Democrat in his teens and finished his life as a Neoplatonist Christian. One of the Russian revisionist Marxists, he was then involved in the Kadet Party during the 1905...