"The Secret Teachings of All Ages" by Manly P. Hall is a comprehensive encyclopedia of esoteric knowledge, first published in 1928. It explores ancient mythology, occult traditions, and philosophical systems, covering topics such as Rosicrucianism, Freemasonry, alchemy, Kabbalah, Tarot, pyramids, and Pythagorean philosophy. The book distills complex arcane subjects into an accessible yet scholarly format, featuring over 200 illustrations. Hall presents it as a codex to the hidden wisdom of the ages, revealing a unifying spiritual truth beneath diverse belief systems.