Whether or not you can observe a thing depends upon the theory you use. It is the theory which decides what can be observed.

I refuse to make money out of my science. My laurel is not for sale like so many bales of cotton.

Great spirits often meet violent oppisition with mediocre minds.

Every day, man is making bigger and better fool-proof things, and every day, nature is making bigger and better fools. So far, I think nature is winning.

Man can find meaning in life only through devoting himself to society.

There is no salvation for civilization, or even the human race, other than the creation of a world government.

All our thinking is of this nature, a free play with concepts.