Romanian born historian of religions whose early research was into religious experience in Hindu traditions, especially yoga. From 1928–31 he was a student of Sanskrit and Indian philosophy at the University of Calcutta, following which he spent six months in an āśram at Rishikesh. Returning to Bucharest, he completed his PhD thesis, which was subsequently translated into English (1954) as Yoga: Immortality and Freedom. He continued his academic career in Romania, Paris, and Chicago, publishing widely and influentially on myth, comparative religion, and the history of religious ideas. The Encyclopedia of Religion (1987) was produced under his general editorship.