Deirdre Bair's biography of C.G. Jung

I'm half way through Deirdre Bair's exhaustive and exhausting biography of C.G. Jung. If you care about the details of how archetypes, the collective unconscious, etc. came into being, this is a great resource. Factoid: as Jung began to formulate his theory of psychological types, initially introverts were thought to be "thinking" and extroverts, "feeling." It was only some years later that all eight types and their independent distributions came into being.