1936 he had a brief and unsatisfactory meeting with Freud.

In 1942, Perls joined the South African army, and he served as an army psychiatrist with the rank of captain until 1946. While in South Africa, Perls was influenced by the "holism" of Jan Smuts. During this period Fritz Perls co-wrote his first book, Ego, Hunger, and Aggression (published in 1942 and re-published in 1947). Laura Perls wrote two chapters of the book, although when it was re-published in the United