My only refuge, as a serious young man, from the despair of my financial burden to my family, is that I did everything I could to never permit myself any amusements or diversions except those afforded by my studies.

The great need to grasp principles had caused me to spend most of my time on fruitless persuits.

the scientist's religious feeling takes the form of a rapturous amazement at the harmony of natural law, which reveals an intelligence of such superiority that, compared with it, all the systematic thinking and acting of human beings is utterly insignificant reflection. This feeling is the guiding principle of his life and work, in so far as he succeeds in keeping himself from the shackles of selfish desire. It is beyond question closely akin to that which has possessed the religious geniuses of all ages.

I don't teach my students, I provide the circumstances in which they can learn.

Relativity teaches us the connection between the different descriptions of one and the same reality.

A scientist is a mimosa when he himself has made a mistake, and a roaring lion when he discovers a mistake of others.

Human beings are not condemned, because of their biological constitution, to annihilate each other or to be at the mercy of a cruel, self-inflicted fate.