Fritz Perls's name is inextricably linked with Gestalt therapy and the movement it inspired during the 1960s. In a moment of uncharacteristic modesty, Perls once maintained that he was not so much the founder of the movement as the “finder.” Indeed, Perls was somewhat of a theoretical magpie, borrowing from whatever he needed at the time and whatever suited him to inform this new therapy. Later he was to suggest, in a more characteristically brash manner that he might just be the “creator of a ‘new’ method of treatment and the exponent of a viable philosophy which could do something for mankind” (Shepard, p. 1, 1975). This modesty/immodesty split was but one of the many splits that typified Perls's world and his writings and that got imported into the theory and practice.

Gestalt therapy, as it was articulated over time, rested on strands of philosophy and psychology from phenomenology, Zen Buddhism, depth psychology, psychodrama, holism, existentialism, and a theory of perception articulated by a small circle of German psychologists in the opening decades of the twentieth century, which was known as Gestalt psychology. Despite its hybrid nature, Perls' Gestalt therapy is most closely associated in many people's minds with German Gestalt theory, though this notion was thoroughly repudiated by the Gestalt psychologist and historian Mary Henle (1978) in an excoriating piece on the distinctions between the two bodies of thought.