2015 Reprint of 1936 Edition. Full facsimile of the original edition. Not reproduced with Optical Recognition Software. Topological psychology may be described non-technically as an attempt to comprehend human behavior in terms of the objects which are present and of the relations among events taking place in a given environment (life-span). Lewin contends that it provides the basis for a truly scientific psychology. The Lewin's equation B = ƒ(P E) is a psychological equation of behavior developed by Kurt Lewin. It states that behavior is a function of the person in their environment. The equation is the psychologist's most well known formula in social psychology of which Lewin was a modern pioneer. When first presented in Lewin's book Principles of Topological Psychology published in 1936 it contradicted most popular theories in that it gave importance to a person's momentary situation in understanding his or her behavior rather than relying entirely on the past.