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

Any government is evil if it carries within it the tendency to deteriorate into Tyranny. The danger of such deterioration is more acute in a country in which the government has authority not only over the armed forces but also over every channel of education and information.

Science is a wonderful thing if one does not have to earn one's living at it. One should earn one's living by work of which one is sure one is capable. Only when we do not have to be accountable to anybody can we find joy in scientific endeavor.

Do not grow old, no matter how long you live. Never cease to stand like curious children before the Great Mystery into which we were born.

We have to do the best we are capable of. This is our sacred human responsibility.

The true sign of intelligence is not knowledge but imagination.

I want to know what God thinks. The rest are details.