The ancient practice of alchemy, which thrived in Europe until the seventeenth century, dealt with the phenomenon of transformation--not only of materials (ore into gold) but also of the human spirit (self into Other). Through their work in the material realm, alchemists discovered personal rebirth as well as a linking between outer and inner dimensions.

C. G. Jung first turned to alchemy for personal illumination in coping with trauma brought on by his break with Freud. Alchemical symbolism eventually suggested to Jung that there was a process in the unconscious, one...