Field theory is centered around the idea that a person's life space determines their behavior.
[5] He then extended this original equation by suggesting that the whole situation could be roughly split into two parts: the person (P) and the environment (E).
[7] Lewin held that the variables in the equation (e.g. P and E) could be replaced with the specific, unique situational and personal characteristics of the individual.
As a result, he also believed that his formula, while seemingly abstract and theoretical, had distinct concrete applications for psychology.
[7] Lewin's field theory holds that a number of different and competing forces combine to result in the totality of the situation.
Lewin emphasizes that the desires and motivations within the person and the situation in its entirety, the sum of all these competing forces, combine to form something larger: the life space.
"[6]Thus, Lewin believed he succeeded in creating an applicable theory that was also "flexible enough to do justice to the enormous differences between the various events and organisms.
"[6] Further, Lewin stated that:"The question whether heredity or environment plays the greater part also belongs to this kind of thinking.
The transition of the Galilean thinking involved a recognition of the general validity of the thesis: An event is always the result of the interaction of several facts.
"[5] In Lewin's original proposal of his equation, he did not specify how exactly the person and the environment interact to produce behavior.
Most theories tended to focus on looking at an individual's past in order to explain their present behavior, such as Sigmund Freud's psychoanalysis.
Past events can only have a position in the historical causal chains whose interweavings create the present situation.