Never regard study as a duty, but as the enviable opportunity to learn

I see in Nature a magnificent structure... that must fill a thinking person with a feeling of humility.

One has to realize that the powerful industrial groups concerned in the manufacture of arms are doing their best in all countries to prevent the peaceful settlement of international disputes, and that rulers can achieve this great end only if they are sure of the vigorous support of the majority of their peoples.

My political ideal is democracy. Let every man be respected as an individual and no man idolized.

Concern for man and his fate must always form the chief interest of all technical endeavors. Never forget this in the midst of your diagrams and equations.

All our thoughts and concepts are called up by sense-experiences and have a meaning only in reference to these sense-experiences. On the other hand, however, they are products of the spontaneous activity of our minds; they are thus in no wise logical consequences of the contents of these sense-experiences. If, therefore, we wish to grasp the essence of a complex of abstract notions we must for the one part investigate the mutual relationships between the concepts and the assertions made about them; for the other, we must investigate how they are related to the experiences.

Do not grow old, no matter how long you live.