1946 286pp 1947 279pp 1949 302pp Philosophical Publishing Company. Illustrated. Uniform green cloth with design and titling stamped in gilt. VG.

Three volume set detailing the history, philosophy, and spiritual practices of the Rosicrucian Order from Clymer's perspective as a Rosicrucian Supreme Grand Master. The work covers topics such as Rosicrucian origins, principles (Mentalism, Vibration, and Cause and Effect), meditation, and spiritual development, serving as both an introduction and a reference for the esoteric tradition. Clymer's writings are a significant part of modern Rosicrucian literature, though they present his specific interpretation of the order's teachings.