I think, therefore I am.
Except our own thoughts, there is nothing absolutely in our power.
It is not enough to have a good mind the main thing is to use it well.
In order to improve the mind, we ought less to learn, than to contemplate.
The greatest minds are capable of the greatest vices as well as of the greatest virtues.
Each problem that I solved became a rule, which served afterwards to solve other problems.
When any one has offended me, I try to raise my soul so high that the offence cannot reach it.
Nothing is more fairly distributed than common sense - no one needs more of it than one already has
The first precept was never to accept a thing as true until I knew it as such without a single doubt.
It is only prudent never to place complete confidence in that by which we have even once been deceived.