If a man aspires towards a righteous life, his first act of abstinence is from injury to animals.

My success wasn't so much due to intelligence, but the fact that I stuck with problems longer.

In the matter of physics, the first lessons should contain nothing but what is experimental and interesting to see. A pretty experiment is in itself often more valuable than twenty formulae extracted from our minds.

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

Let every man judge according to his own standards, by what he has himself read, not by what others tell him.

How can cosmic religious feeling be communicated from one person to another, if it can give rise to no definite notion of a God and no theology? In my view, it is the most important function of art and science to awaken this feeling and keep it alive in those who are receptive to it.

I would teach peace rather than war, love rather than hate.