Il n'est pas certain que tout soit incertain. (Translation: It is not certain that everything is uncertain.)

If we regulate our conduct according to our own convictions, we may safely disregard the praise or censure of others.

Our nature consists in motion; complete rest is death.

Do they think that they have given us great pleasure by telling us that they hold our soul to be no more than wind or smoke, and saying it moreover in tones of pride and satisfaction? Is this then something to be said gaily? Is it not on the contrary something to be said sadly, as being the saddest thing in the world?

The state of man is inconstancy, ennui, anxiety.

Law, without force, is impotent.

To have no time for philosophy is to be a true philosopher.