Great minds think for themselves.

Human beings are never to be treated as a means but always as ends.

The wise man can change his mind; the stubborn one, never.

I had therefore to remove knowledge, in order to make room for belief.

[A ruler is merely] the trustee of the rights of other men and he must always stand in dread of having in some way violated these rights.

Freedom is independence of the compulsory will of another, and in so far as it tends to exist with the freedom of all according to a universal law, it is the one sole original inborn right belonging to every man in virtue of his humanity.

The sceptics, a kind of nomads, despising all settled culture of the land, broke up from time to time all civil society. Fortunately their number was small, and they could not prevent the old settlers from returning to cultivate the ground afresh, though without any fixed plan or agreement.