An optimist may see a light where there is none, but why must the pessimist always run to blow it out?
Perfect numbers like perfect men are very rare.
I think; therefore I am.
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.
Except our own thoughts, there is nothing absolutely in our power.
At the time, my grandparents told my mom, Lordy, what is Shannen doing? Now I've calmed down. [on her reputation for bad behavior]
If I found any new truths in the sciences, I can say that they follow from, or depend on, five or six principal problems which I succeeded in solving and which I regard as so many battles where the fortunes of war were on my side.
Of all things, good sense is the most fairly distributed: everyone thinks he is so well supplied with it that even those who are the hardest to satisfy in every other respect never desire more of it than they already have.
I think therefore I exist.
Travelling is almost like talking with those of other centuries.
Whenever anyone has offended me, I try to raise my soul so high that the offense cannot reach it
Cogito Ergo SumI think therefore I exist.
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.
So blind is the curiosity by which mortals are possessed, that they often conduct their minds along unexplored routes, having no reason to hope for success, but merely being willing to risk the experiment of finding whether the truth they seek lies there.
When it is not in our power to follow what is true, we ought to follow what is most probable.
The senses deceive from time to time, and it is prudent never to trust wholly those who have deceived us even once.
Everything is self-evident.
I am indeed amazed when I consider how weak my mind is and how prone to error.
The reading of all good books is like a conversation with the finest minds of past centuries.
The last rule was to make enumerations so complete, and reviews so comprehensive, that I should be certain of omitting nothing.