I think therefore I am.
To know what people really think, pay regard to what they do, rather than what they say.
The reading of all good books is like a conversation with all the finest men of past centuries.
Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has.
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.
Whenever anyone has offended me, I try to raise my soul so high that the offense cannot reach it.
It is not enough to have a good mind, the main thing is to use it well.
There is nothing so strange and so unbelievable that it has not been said by one philosopher or another.
Everything is self-evident.
Divide each difficulty into as many parts as is feasible and necessary to resolve it.
Except our own thoughts, there is nothing absolutely in our power.