Russian philosopher and theologian. Until 1881 he shared the antipathy of many Slavophils for the RC Church; he later changed his attitude and carried on negotiations with J. G. Strossmayer for a reunion of the Orthodox and RC Churches. His La Russie et l'Église universelle (1889) met with strong opposition in Russia, and he was forbidden by the Holy Synod to write on religious questions. In 1896 he received Communion in a RC church in Moscow, an act, he believed, of adhesion to the universal Church. In his philosophical system he admitted Gnostic elements and upheld the existence of a female principle, ‘Sophia’ (Wisdom) or the world-soul. His influence did much to bring Russian intellectuals to a definitely religious and Christian view of the world.