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.
It is not enough to have a good mind. The main thing is to use it well.
The greatest minds are capable of the greatest vices as well as of the greatest virtues.
To know what people really think, pay regard to what they do, rather than what they say.
Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has.
Each problem that I solved became a rule, which served afterwards to solve other problems.
I am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.
The greatest minds are capable of the greatest vices as well as of the greatest virtues.