It's easier to be original and foolish than original and wise.

Every present state of a simple substance is the natural consequence of its preceding state, in such a way that its present is big with its future.

There is no way in which a simple substance could begin in the course of nature, since it cannot be formed by means of compounding.

Of what use would it be to you, sir, to become King of China on condition that you forgot what you have been? Would it not be the same as if God, at the same time he destroyed you, created a King in China?

Music is the pleasure the human mind experiences from counting without being aware that it is counting.

The knowledge which we have acquired ought not to resemble a great shop without order, and without an inventory; we ought to know what we possess, and be able to make it serve us in need.

Each portion of matter may be conceived of as a garden full of plants, and as a pond full of fishes. But each branch of the plant, each member of the animal, each drop of its humors, is also such a garden or such a pond.