You can't solve problems with the same thinking that caused them.

The idea of a personal God is an anthropological concept which I am unable to take seriously.

I do not believe in a personal God and I have never denied this but have expressed it clearly.

He who finds a thought that lets us a little deeper into the eternal mystery of nature has been granted great peace.

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

The Constitution only guarantees the American people the right to pursue happiness. You have to catch it yourself. A table, a chair, a bowl of fruit and a violin; what else does a man need to be happy?

The daily struggle does not arise from a purpose or a program, but from an immediate need.