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 ….

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

There is nothing so practical as a good theory..

Social action, just like physical action, is steered by perception..

When we are young we are like a flowing river - and then we freeze..

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

Learning is more effective when it is an active rather than a passive process..

Every psychological event depends upon the state of the person and at the same time on the environment, although their relative importance is differe….

No research without action, no action without research..

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

The American culture ideal of the "self-made-man," of everyone "standing on his own feet" seemed as tragic a picture as the initiative-destroying dep….

Fortunately I experienced Max Wertheimer's teaching in Berlin and collaborated for over a decade with Wolfgang Köhler. I need not emphasize my debts ….

Experience alone does not create knowledge..