Intelligence, guided by kindness, is the highest wisdom. . . .

Science built the Academy, superstition the Inquisition.

In the presence of death I affirm and reaffirm the truth of all that I have said against the superstitions of the world. I would say that much on the subject with my last breath.

Truth is the mother of joy. Truth civilizes, ennobles and purifies. The grandest ambition that can enter the soul is to know the truth.

Our hope of immortality does not come from any religions, but nearly all religions come from that hope.

Blasphemy is an epithet bestowed by superstition upon common sense.

All of the Ten Commandments that are good were old; all that were new art foolish. If Jehovah had been civilized he would have left out the commandment about keeping the Sabbath, and in its place would have said: "Thou shalt not enslave thy fellow-men." He would have omitted the one about swearing, and said: "The man shall have but one wife, and the woman but one husband." He would have left out the one about graven images, and in its stead would have said: "Thou shalt not wage wars of extermination, and thou shalt not unsheathe the sword except in self-defence.