The senses deceive from time to time, and it is prudent never to trust wholly those who have deceived us even once.

... regard this body as a machine which, having been made by the hand of God, is incomparably better ordered than any machine that can be devised by man, and contains in itself movements more wonderful than those in any machine. ... it is for all practical purposes impossible for a machine to have enough organs to make it act in all the contingencies of life in the way in which our reason makes us act.

It is not enough to have a good mind. The main thing is to use it well.

There is a little gland in the brain in which the soul exercises its functions in a more particular way than in the other parts.

Human wisdom remains always one and the same although applied to the most diverse objects and it is no more changed by their diversity than the sunshine is changed by the variety of objects which it illuminates.

It is possible that I am dreaming right now and that all of my perceptions are false.

Common sense is the most fairly distributed thing in the world, for each one thinks he is so well-endowed with it that even those who are hardest to satisfy in all other matters are not in the habit of desiring more of it than they already have.