Only by the concrete whole which comprises the object and the situation are the vectors which determine the dynamics of the event defined. - Kurt Zadek Lewin

In the psychological fields most fundamental to the whole behavior of living things the transition seems inevitable to a Galileian view of dynamics, which derives all its vectors not from single isolated objects, but from the mutual relations of the factors in the concrete whole situation, that is, essentially, from the momentary condition of the individual and the structure of the psychological situation. The dynamics of the processes is always to be derived from the relation of the concrete individual to the concrete situation, and, so far as internal forces are concerned, from the mutual relations of the various functional systems that make up the individual.

[Satiation may spill over outside the specific task to structurally similar tasks) and may end up in an early] exhaustion of the occupational will.

An attempt to improve intergroup relations has to face a wide variety of tasks. It deals with problems of attitude and stereotypes in regard to other groups and to one's own group, with problems of development of attitudes and conduct during childhood and adolescence, with problems of housing, and the change of the legal structure of the community; it deals with problems of status and caste, with problems of economic discrimination, with political leadership and with leadership in many aspects of community life. It deals with the small social body of a family, a club or a friendship group, with the larger social body of a school or a school system, with neighborhoods and with social bodies of the size of a community, of the state, a nation and with international problems.