The pineal gland has long been a subject of fascination for mystics, philosophers, and occultists. Often referred to as the "Seat of the Soul" or the "Third Eye," this tiny, pinecone-shaped endocrine gland deep within the brain is central to the esoteric teachings of Manly P. Hall. In his landmark works, Hall explores the pineal gland not just as a biological organ, but as a bridge between the physical and spiritual realms—the literal "Eye of God" within man.

: The historical root behind the ubiquitous symbol found in Egyptian iconography (the Eye of Horus) and Masonic tradition. The Alchemical Process of Awakening