Manly Palmer Hall (1901-1990) was a Canadian-born author, lecturer, mystic, and scholar of comparative religion, mythology, philosophy, and the Western esoteric tradition. He devoted his life to studying the symbolic systems through which civilizations have expressed their spiritual and philosophical ideas. In 1934, he founded the Philosophical Research Society in Los Angeles, creating an institution dedicated to the study of wisdom traditions from around the world. Hall wrote more than 150 books and essays, but The Secret Teachings of All Ages, completed while he was still in his twenties, remains his defining achievement. Its extraordinary range, detailed scholarship, and extensive illustrations established Hall as one of the twentieth century's most influential interpreters of occult philosophy and ancient symbolism.