On Christmas Day in 1913, while deeply immersed in his experiments with active imagination, Carl Gustav Jung experienced a visionary metamorphosis: he was transformed into a lion-headed deity encoiled by a serpent. This was the enigmatic figure of Aion, the god of Eternal Time from the ancient Mithraic mysteries. In this lecture, religious studies scholar Dr. Hereward Tilton explores the occultist inspiration of this harrowing experience of ego-death. Above all, the influence of G. R. S. Mead allows us to accurately situate Jung’s work within the Western gnostic traditions.