He who falls obstinate in his courage, if he falls he fights from his knees.

The recognition of virtue is not less valuable from the lips of the man who hates it, since truth forces him to acknowledge it; and though he may be unwilling to take it into his inmost soul, he at least decks himself out in its trappings.

Seeing that the Senses cannot decide our dispute, being themselves full of uncertainty, we must have recourse to Reason; there is no reason but must be built upon another reason: so here we are retreating backwards to infinity.

I, who am king of the matter I treat, and who owe an accounting for it to no one, do not for all that believe myself in all I write. I often hazard sallies of my mind which I mistrust.

To compose our character is our duty, not to compose books, and to win, not battles and provinces, but order and tranquillity in our conduct.

If your doctor does not think it good for you to sleep, to drink wine, or to eat of a particular dish, do not worry; I will find you another who will not agree with him.

In truth, knowledge is a great and very useful quality; those who despise it give evidence enough of their stupidity. Yet I do not set its value at that extreme measure that some attribute to it.