Throughout the history of modern psychiatry, descriptive methods and operational definitions have featured prominently in endeavors to objectively refer to and classify mental disorders. An alternative to these descriptive approaches is the argument based on the concepts of “natural kinds” and “dysfunction” such as Wakefieldʼs “harmful dysfunction” model. However, none of these approaches seem promising for understanding the nature of mental disorders. This paper proposes that we abandon the prevalent tendency to objectively classify mental disorders, revert to the original meaning of psychiatry (Psychiaterie), a term coined by J. C. Reil, as a method of therapy, and reexamine the concept of mental disorder.