Hermann Rorschach was a Swiss psychiatrist and psychoanalyst. His education in art helped to spur the development of a set of inkblots that were used experimentally to measure various unconscious parts of the subject's personality. His method has come to be referred to as the Rorschach test, iterations of which have continued to be used over the years to help identify personality, psychotic, and neurological disorders. Rorschach continued to refine the test until his premature death at age 37.

Paul Eugen Bleuler was a Swiss psychiatrist and humanist most notable for his contributions to the understanding of mental illness. He coined several psychiatric terms including "schizophrenia", "schizoid", "autism", depth psychology and what Sigmund Freud called "Bleuler's happily chosen term ambivalence".