Russian existentialist philosopher. From 1922 he lived as an émigré, mainly in Paris. His works portray a philosophical evolution from Marxism to Idealism, and thence to Orthodoxy or would-be Orthodox mysticism. The most theological, Freedom and the Spirit (1927; Eng. tr., 1935), sets out his version of religious existentialist or personalist philosophy. He believed that the ‘contradictions of modern history’ portended a new era of ‘divine-human creation’. His critical, nonconformist allegiance to Orthodoxy was combined with moral and social radicalism and an eventual acceptance of post-Revolutionary Russia.