I am indeed amazed when I consider how weak my mind is and how prone to error.
The greatest minds are capable of the greatest vices as well as of the greatest virtues.
Except our own thoughts, there is nothing absolutely in our power.
Each problem that I solved became a rule which served afterwards to solve other problems.
Each problem that I solved became a rule, which served afterwards to solve other problems.
Cogito ergo sum.
An optimist may see a light where there is none, but why must the pessimist always run to blow it out?
The two operations of our understanding, intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge.
Everything is self-evident.
Whenever anyone has offended me, I try to raise my soul so high that the offense cannot reach it.
Perfect numbers like perfect men are very rare.
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 am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.
I know not if I was then a man dreaming I was a butterfly, or if I am now a butterfly dreaming I am a man.
Divide each difficulty into as many parts as is feasible and necessary to resolve it.
It is not enough to have a good mind, the main thing is to use it well.
A state is better governed which has few laws, and those laws strictly observed.
The senses deceive from time to time, and it is prudent never to trust wholly those who have deceived us even once.
The reading of all good books is like a conversation with the finest minds of past centuries.
In order to improve the mind, we ought less to learn, than to contemplate.
The first precept was never to accept a thing as true until I knew it as such without a single doubt.
I think; therefore I am.
Travelling is almost like talking with those of other centuries.
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.
Illusory joy is often worth more than genuine sorrow.
The reading of all good books is like a conversation with all the finest men of past centuries.
