Field theory is a psychological theory which examines patterns of interaction between the individual and the total field, or environment. The concept was developed by Kurt Lewin, a Gestalt psychologist, in the 1940s and 1950s.
Field theory holds that behavior must be derived from a totality of coexisting facts. These coexisting facts make up a "dynamic field", which means that the state of any part of the field depends on every other part of it. Behavior depends on the present field rather than on the past or the future.