One cannot learn so well as by experiencing it oneself.

A forced faithfulness is a bitter fruit for all concerned.

The ability to portray people in still life and in motion requires the highest measure of intuition and talent.

Whether or not you can observe a thing depends upon the theory you use. It is the theory which decides what can be observed.

The most important thing is to not stop questioning.

The Jewish scriptures admirably illustrate the development from the religion of fear to moral religion, a development continued in the New Testament. The religions of all civilized peoples, especially the peoples of the Orient, are primarily moral religions.

If one holds these high principles clearly before one's eyes, and compares them with the life and spirit of our times, then it appears glaringly that civilized mankind finds itself at present in grave danger. In the totalitarian states it is the rulers themselves who strive actually to destroy that spirit of humanity. In less threatened parts it is nationalism and intolerance, as well as the oppression of the individuals by economic means, which threaten to choke these most precious traditions.