Look somewhere else for someone who can follow you in your researches about numbers. For my part, I confess that they are far beyond me, and I am competent only to admire them.

As we speak of poetical beauty, so ought we to speak of mathematical beauty and medical beauty. But we do not do so; and that reason is that we know well what is the object of mathematics, and that it consists in proofs, and what is the object of medicine, and that it consists in healing. But we do not know in what grace consists, which is the object of poetry.

Since we cannot be universal and know all that is to be known of everything, we ought to know a little about everything. For it is far better to know something about everything than to know all about one thing. This universality is the best. If we can have both, still better; but if we must choose, we ought to choose the former.

Few friendships would survive if each one knew what his friend says of him behind his back.

However vast a man's spiritual resources, he is capable of but one great passion.

Our nature lies in movement; complete calm is death.

On the occasions when I have pondered over men's various activities, the dangers and worries they are exposed to at Court or at war, from which so many quarrels, passions, risky, often ill-conceived actions and so on are born, I have often said that man's unhappiness springs from one thing alone, his incapacity to stay quietly in one room.