Carl Jung was a Swiss psychiatrist who founded analytical psychology. He proposed concepts like archetypes, the collective unconscious, and individuation. Jung believed that archetypes like the mother, shadow, and persona exist in the collective unconscious and can be experienced through symbols. He also developed ideas about personality types, the dynamics of opposites in the psyche, and the shift from acquiring identity in the first half of life to a focus on the soul in the second half. While influential, some of Jung's theories like the reality of the collective unconscious remain challenged.