The movement of comets is part of the ordinary works of nature which, without regard to the happiness or misery of mankind, are transported from one part of the heavens to another by virtue of the general laws of motion.

The antiquity and general acceptance of an opinion is not assurance of its truth.

It has been asserted, that a moral Atheist would be a monster beyond the power of nature to create: I reply, that it is not more strange for an Atheist to live virtuously, than for a Christian to abandon himself to crime! If we believe the last kind of monster, why dispute the existence of the first?

There was no other God, religion, or lawful magistracy, than conscience, which teaches all men the precepts of Justice, to do no injury, to live honestly, and give everyone his due.

It is thus tolerance that is the source of peace, and intolerance that is the source of disorder and squabbling.

The furnace of affliction refines us from earthly drossiness, and softens us for the impression of God's own stamp.

I get up and retire when I wish. I go out if I wish and I do not go out if I do not desire to do so, except for the two days on which I give lectures.

No nations are more warlike than those which profess Christianity.

In matters of religion, it is very easy to deceive a man and very hard to undeceive him.

I know too much to be a sceptic and too little to be a dogmatist.

It is only common prejudice that induces us to believe that atheism is a fearful state.

Properly speaking, history is nothing but the crimes and misfortunes of the human race.

I am a good Protestant, and in the full sense of the term, for from the bottom of my soul, I protest against everything that is said, and everything that is done.