René Descartes Quotes

“It is not enough to have a good mind. The main thing is to use it well.”

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

“I think, therefore I am.”

“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.”

“The greatest minds are capable of the greatest vices as well as of the greatest virtues.”

“There is nothing more ancient than the truth.”

“The entire method consists in the order and arrangement of the things to which the mind’s eye must turn so that we can discover some truth.”

“It is best not to go on for great quest for truth, it will only make you miserable”

“To live without philosophizing is in truth the same as keeping the eyes closed without attempting to open them.”

“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.”

“But in my opinion, all things in nature occur mathematically.”

“Mr. Clerselier has written me that you are expecting from him my Meditations… in order to present them to the queen of the land. …If I had only been as wise as they say the savages persuaded themselves that the monkeys were, I never would have become known as a maker of books: Since it is said that they imagined that the monkeys could indeed speak, if they wanted to, but that they chose not to so lest they be forced to work. And since I had not the same prudence to abstain from writing, I now have neither as much liesure nor as much peace as I would have had if I had kept quiet. But since the mistake has already been made, and since I am now known by an infinity of people at the academy, who look askance at my writings and scour them for means of harming me, I do have great hope of being known to persons of great merit, whose power and virtue could protect me.”

“My third maxim was to endeavor always to conquer myself rather than fortune, and change my desires rather than the order of the world.”

“Except our own thoughts, there is nothing absolutely in our power.”

“Common sense is the most widely shared commodity in the world, for every man is convinced that he is well supplied with it.”

“Conquer yourself rather than the world.”

“Doubt is the origin of wisdom”

“To know what people really think, pay attention to what they do, rather than what they say.”

“I desire to live in peace and to continue the life I have begun under the motto 'to live well you must live unseen”

“Masked, I advance.”

“It is only prudent never to place complete confidence in that by which we have even once been deceived.”

“You just keep pushing. You just keep pushing. I made every mistake that could be made. But I just kept pushing.”

“In order to improve the mind, we ought less to learn than to contemplate.”

“For I found myself embarrassed with so many doubts and errors that it seemed to me that the effort to instruct myself had no effect other than the increasing discovery of my own ignorance”

“He who hid well, lived well.”

“Each problem that I solved became a rule which served afterwards to solve other problems”

“At last I will devote myself sincerely and without reservation to the general demolition of my opinions.”

“Let whoever can do so deceive me, he will never bring it about that I am nothing, so long as I continue to think I am something.”

“Because reason… is the only thing that makes us men, and distinguishes us from the beasts, I would prefer to believe that it exists, in its entirety, in each of us…”

“With me, everything turns into mathematics.”

“Good sense is the most equitably distributed of all things because no matter how much or little a person has, everyone feels so abundantly provided with good sense that he feels no desire for more than he already possesses.”

“The reading of all good books is indeed like a conversation with the noblest men of past centuries who were the authors of them, nay a carefully studied conversation, in which they reveal to us none but the best of their thoughts.”

“Bad books engender bad habits, but bad habits engender good books.”

“I am accustomed to sleep and in my dreams to imagine the same things that lunatics imagine when awake.”

“I doubt, therefore I think, therefore I am.”
Cogito, ergo sum.

“No doubt you know that Galileo had been convicted not long ago by the Inquisition, and that his opinion on the movement of the Earth had been condemned as heresy. Now I will tell you that all things I explain in my treatise, among which is also that same opinion about the movement of the Earth, all depend on one another, and are based upon certain evident truths. Nevertheless, I will not for the world stand up against the authority of the Church. …I have the desire to live in peace and to continue on the road on which I have started.”

“Thus, all unknown quantities can be expressed in terms of a single quantity, whenever the problem can be constructed by means of circles and straight lines, or by conic sections, or even by some other curve of degree not greater than the third or fourth.
But I shall not stop to explain this in more detail, because I should deprive you of the pleasure of mastering it yourself, as well as of the advantage of training your mind by working over it, which is in my opinion the principal benefit to be derived from this science. Because, I find nothing here so difficult that it cannot be worked out by anyone at all familiar with ordinary geometry and with algebra, who will consider carefully all that is set forth in this treatise.”

“Staying as I am, one foot in one country and the other in another, I find my condition very happy, in that it is free.”

“No more useful inquiry can be proposed than that which seeks to determine the nature and the scope of human knowledge. … This investigation should be undertaken once at least in his life by anyone who has the slightest regard for truth, since in pursuing it the true instruments of knowledge and the whole method of inquiry come to light. But nothing seems to me more futile than the conduct of those who boldly dispute about the secrets of nature … without yet having ever asked even whether human reason is adequate to the solution of these problems.”

“What I have given in the second book on the nature and properties of curved lines, and the method of examining them, is, it seems to me, as far beyond the treatment in the ordinary geometry, as the rhetoric of Cicero is beyond the a, b, c of children.”

“With me, everything turns into mathematics.
More closely translated as: but in my opinion, all things in nature occur mathematically.”
Mais apud me omnia fiunt Mathematicè in Natura

“I could give here several other ways of tracing and conceiving a series of curved lines, each curve more complex than any preceding one, but I think the best way to group together all such curves and them classify them in order, is by recognizing the fact that all points of those curves which we may call "geometric," that is, those which admit of precise and exact measurement, must bear a definite relation to all points of a straight line, and that this relation must be expressed by a single equation. If this equation contains no term of higher degree than the rectangle of two unknown quantities, or the square of one, the curve belongs to the first and simplest class, which contains only the circle, the parabola, the hyperbola, and the ellipse; but when the equation contains one or more terms of the third or fourth degree in one or both of the two unknown quantities (for it requires two unknown quantities to express the relation between two points) the curve belongs to the second class; and if the equation contains a term of the fifth or sixth degree in either or both of the unknown quantities the curve belongs to the third class, and so on indefinitely.”

“M. Desargues puts me under obligations on account of the pains that it has pleased him to have in me, in that he shows that he is sorry that I do not wish to study more in geometry, but I have resolved to quit only abstract geometry, that is to say, the consideration of questions which serve only to exercise the mind, and this, in order to study another kind of geometry, which has for its object the explanation of the phenomena of nature… You know that all my physics is nothing else than geometry.”

“Discourse on the Method of Rightly Conducting the Reason, and Seeking Truth in the Sciences”