Superstition is more injurious to God than atheism.

As long as the centuries continue to unfold, the number of books will grow continually, and one can predict that a time will come when it will be almost as difficult to learn anything from books as from the direct study of the whole universe. It will be almost as convenient to search for some bit of truth concealed in nature as it will be to find it hidden away in an immense multitude of bound volumes.

Isn't it better to have men being ungrateful than to miss a chance to do good?

A thing is not proved because no one has ever questioned it... Skepticism is the first step toward truth.

If there are one hundred thousand damned souls for one saved soul, the devil has always the advantage without having given up his son to death.

A nation which thinks that it is belief in God and not good law which makes people honest does not seem to me very advanced.

I have only a small flickering light to guide me in the darkness of a thick forest. Up comes a theologian and blows it out.