If you disturb the colors of the rainbow, the rainbow is no longer beautiful.

The most dangerous madmen are those created by religion, and people whose aim is to disrupt society always know how to make good use of them on occasion.

If reason be a gift of Heaven, and we can say as much of faith, Heaven has certainly made us two gifts not only incompatible, but in direct contradiction to each other. In order to solve the difficulty, we are compelled to say either that faith is a chimera or that reason is useless.

You risk just as much in being credulous as in being suspicious.

I feel, I think, I judge; therefore, a part of organized matter like me is capable of feeling, thinking, and judging.

The fact is that she was terribly undressed and I was extremely undressed too. The fact is that I still had my hand where she didn't have anything and she had hers where the same wasn't quite true of me. The fact is that I found myself underneath her and consequently she found herself on top of me.

Superstition is more injurious to God than atheism.