There is nothing so practical as a good theory.

If you want truly to understand something, try to change it.

A successful individual typically sets his next goal somewhat, but not too much, above his last achievement.

The history of acceptance of new theories frequently shows the following steps: At first the new idea is treated as pure nonsense, not worth looking at. Then comes a time when a multitude of contradictory objections are raised, such as: the new theory is too fancy, or merely a new terminology; it is not fruitful, or simply wrong. Finally a state is reached when everyone seems to claim that he had always followed this theory. This usually marks the last state before general acceptance.

Every psychological event depends upon the state of the person and at the same time on the environment, although their relative importance is different in different cases

Fortunately I experienced Max Wertheimer's teaching in Berlin and collaborated for over a decade with Wolfgang Köhler. I need not emphasize my debts to these outstanding personalities. The fundamental ideas of Gestalt theory are the foundation of all our investigations in the field of the will, of affection, and of the personality.

If you want to learn about an organization, try to change it.