Everything is self-evident.
In order to improve the mind, we ought less to learn, than to contemplate.
Illusory joy is often worth more than genuine sorrow.
If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.
I hope that posterity will judge me kindly, not only as to the things which I have explained, but also to those which I have intentionally omitted so as to leave to others the pleasure of discovery.
I am indeed amazed when I consider how weak my mind is and how prone to error.
Except our own thoughts, there is nothing absolutely in our power.
Divide each difficulty into as many parts as is feasible and necessary to resolve it.
Each problem that I solved became a rule, which served afterwards to solve other problems.
A state is better governed which has few laws, and those laws strictly observed.
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.
It is not enough to have a good mind; the main thing is to use it well.
I am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.
Travelling is almost like talking with those of other centuries.
It is only prudent never to place complete confidence in that by which we have even once been deceived.