Manly Palmer Hall (March 18, 1901 – August 29, 1990) was a Canadian-born mystic, eclectic philosopher and founder of the Philosophical Research Society, a modern equivalent of the school of Pythagoras. [1]He was the 20th century’s most prolific writer on mysticism, magic, and ancient Manly Palmer Hall (March 18, 1901 – August 29, 1990) was a Canadian-born mystic, eclectic philosopher and founder of the Philosophical Research Society, a modern equivalent of the school of Pythagoras. [1]He was the 20th century’s most prolific writer on mysticism, magic, and ancient philosophies. He authored more than 200 books and gave more than 8000 lectures, most of them weekly at the headquarters of the Physical Research Institute until shortly before his death. He is best known for his 1928 work The Secret Teachings of All Ages. Hall published his magnum opus, an introduction to ancient symbols and secret traditions, at the age of 27, to immediate acclaim. It is the most important book of the early twentieth-century American occult revival and remains influential to this day.