Manly Palmer Hall is perhaps most famous for his work The Secret Teachings of All Ages: An Encyclopedic Outline of Masonic, Hermetic, Qabbalistic and Rosicrucian Symbolical Philosophy, published in 1928 when he was 27 years old. In 1934, Hall founded the Philosophical Research Society (PRS) in Los Angeles, California, dedicating it to an idealistic approach to the solution of human problems. The PRS claims to be non-sectarian and entirely free from educational, political, or ecclesiastical control, and the Society's programs stress the need for the integration of philosophy, religion, and science into one system of instruction. The PRS Library, a public facility devoted to source materials in obscure fields, has many rare and scarce items now impossible to obtain elsewhere. In his over 70-year career, Hall delivered approximately 8,000 lectures in the United States and abroad, authored over 150 books and essays, and wrote countless magazine articles.