Discourse on the Method

"The greatest minds, as they are capable of the highest excellencies, are open likewise to the greatest aberrations; and those who travel very slowly may yet make far greater progress, provided they keep always to the straight road, than those who, while they run, forsake it."

"Each problem that I solved became a rule, which served afterwards to solve other problems."

"The first precept was never to accept a thing as true until I knew it as such without a single doubt."

"The last rule was to make enumerations so complete, and reviews so comprehensive, that I should be certain of omitting nothing."

"Divide each difficulty into as many parts as is feasible and necessary to resolve it."

"Car ce nest pas assez davoir lesprit bon, mais le principal est de lappliquer bien."

"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. (fr; en)"

"If we consider all external goods as equally beyond our power, we shall no more regret the absence of such goods... when deprived of them without any fault of ours, than our not possessing the kingdoms of China or Mexico; and thus making... a virtue of necessity, we shall no more desire health in disease, or freedom in imprisonment, than we now do bodies incorruptible as diamonds, or the wings of birds to fly with. But I confess there is need of prolonged discipline and frequently repeated meditation to accustom the mind to view all objects in this light; and I believe that in this chiefly consisted the secret of the power of such philosophers as in former times were enabled to rise superior to the influence of fortune, and, amid suffering and poverty, enjoy a happiness which their gods might have envied. For, occupied incessantly with the consideration of the limits prescribed to their power by nature, they became so entirely convinced that nothing was at their disposal except their own thoughts, that this conviction was of itself sufficient to prevent their entertaining any desire of other objects; and over their thoughts they acquired a sway so absolute, that they had some ground on this account for esteeming themselves more rich and more powerful, more free and more happy, than other men who, whatever be the favors heaped on them by nature and fortune, if destitute of this philosophy, can never command the realization of all their desires."

"The long chains of simple and easy reasonings by means of which geometers are accustomed to reach the conclusions of their most difficult demonstrations, had led me to imagine that all things, to the knowledge of which man is competent, are mutually connected in the same way, and that there is nothing so far removed from us as to be beyond our reach, or so hidden that we cannot discover it, provided only we abstain from accepting the false for the true, and always preserve in our thoughts the order necessary for the deduction of one truth from another."

"On ne sauroit rien imaginer de si étranger et si peu croyable, qu’il n’ait été dit par quelqu’un des philosophes..."