When a person opens a book, he can never be in prison.

There is no supernatural, there is only nature. Nature alone exists and contains all. All is. There is the part of nature that we perceive, and the part of nature that we do not perceive. ... If you abandon these facts, beware; charlatans will light upon them, also the imbecile. There is no mean: science, or ignorance. If science does not want these facts, ignorance will take them up. You have refused to enlarge human intelligence, you augment human stupidity. When Laplace withdraws Cagliostro appears.

I'd like a drink. I desire to forget life. Life is a hideous invention by somebody I don't know. It doesn't last, and it's good for nothing. You break your neck simply living.

In saying no to progress, it is not the future which they condemn, but themselves. They give themselves a melancholy disease; they inoculate themselves with the past. There is but one way of refusing tomorrow, that is to die.

Every blade has two edges; he who wounds with one wounds himself with the other.

It is sad to tell, but after having tried society, which had caused his misfortune, he tried Providence which created society, and condemned it also.

Intelligence is the wife, imagination is the mistress, memory is the servant.