All the miseries of mankind come from one thing, not knowing how to remain alone.

We must know where to doubt, where to feel certain, where to submit. He who does not do so, understands not the force of reason.

The art of revolutionizing and overturning states is to undermine established customs, by going back to their origin, in order to mark their want of justice.

If we dreamed the same thing every night, it would affect us much as the objects we see every day. And if a common workman were sure to dream every night for twelve hours that he was a king, I believe he would be almost as happy as a king who should dream every night for twelve hours on end that he was a common workman.

One must have deeper motives and judge everything accordingly, but go on talking like an ordinary person.

There are two excesses: to exclude reason, to admit nothing but reason. The supreme achievement of reason is to realise that there is a limit to reason. Reason's last step is the recognition that there are an infinite number of things which are beyond it. It is merely feeble if it does not go as far as to realise that.

If man made himself the first object of study, he would see how incapable he is of going further. How can a part know the whole?