Carl Jung was born in Switzerland, the son of a Swiss Reform pastor. Having decided to become a psychiatrist, he enrolled in medical school at the University of Basel, from which he received his degree in 1900. Serving as an assistant at the University of Zurich Psychiatric Clinic, Jung worked under psychiatrist Eugen Bleuler (1857-1939), a psychiatrist renowned for his work on schizophrenia. Jung also traveled to France to study with the well-known psychiatrist Pierre Janet (1859-1947) as well. In 1905, he was appointed to a faculty position in psychiatry at the University of Zurich and became a senior physician at its clinic. Eventually, a growing private practice forced him to resign his university position. Jung's early published studies on schizophrenia established his reputation, and he also won recognition for developing a word association test.

Jung had read Sigmund Freud's The Interpretation of Dreams shortly after its publication in 1900 and...