He who finds though that lets us penetrate even a little deeper into the eternal mystery of nature has been granted great grace. He who, in addition, experiences the recognition, sympathy, and help of the best minds of his times, had been given almost more happiness than one man can bear.

I believe in Spinoza's God, who reveals Himself in the lawful harmony of the world, not in a God who concerns Himself with the fate and the doings of mankind... to Rabbi Herbert Goldstein (1929)

I have tried 99 times and have failed, but on the 100th time came success.

Qualities I sought in a scientific theory were naturalness, inner perfection and logical simplicity from an aesthetic approach.

I have not eaten enough of the tree of knowledge, though in my profession I am obligated to feed on it regularly.

I want to go when I want. It is tasteless to prolong life artificially. I have done my share, it is time to go. I will do it elegantly.

In conclusion I wish to say that in working at the problem here dealt with I have had the loyal assistance of my friend and colleague M. Besso, and that I am indebted to him for several valuable suggestions.