Any planned social change will have to consider a multitude of factors characteristic for the particular case. The change may require a more or less … - Kurt Zadek Lewin

The second experiment, with four leaders, makes possible a comparison of the authoritarianism and democracy of four different leaders, and the "laissez-faire" method of two different leaders. In two cases it is also possible to compare the same atmosphere, created by two different leaders with the same club. One other type of control seemed very important, the nature of the club activity, and the physical setting...

We know, since the theory of relativity at least, that empirical sciences are to some degree free in defining dynamical concepts or even in assuming laws, and that only a system as a whole which includes concepts, coordinating definitions, and laws can be said to be either true or false, to be adequate or inadequate to empirical facts. This "freedom," however, is a somewhat doubtful gift. The manifold of possibilities implies uncertainty, and such uncertainty can become rather painful in a science as young as psychology, where nearly all concepts are open and unsettled. As psychology approaches the state of a logically sound science, definitions cease to be an arbitrary matter. They become far-reaching decisions which presuppose the mastering of the conceptual problems but which have to be guided entirely by the objective facts.

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