A perfection of means, and confusion of aims, seems to be our main problem.

Manager solves problems, leader prevents them.

Where the world ceases to be the scene of our personal hopes and wishes, where we face it as free beings admiring, asking and observing, there we enter the realm of Art and Science.

The individual must not merely wait and criticize, he must defend the cause the best he can. The fate of the world will be such as the world deserves.

All the fifty years of conscious brooding have brought me no closer to answer the question, "What are light quanta?" Of course today every rascal thinks he knows the answer, but he is deluding himself.

We owe a lot to the Indians, who taught us how to count, without which no worthwhile scientific discovery could have been made.

If we knew what it was we were doing, it would not be called research, would it?