René Descartes Quotes

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

~ René Descartes

I suppose therefore that all things I see are illusions; I believe that nothing has ever existed of everything my lying memory tells me. I think I have no senses. I believe that body, shape, extension, motion, location are functions. What is there then that can be taken as true? Perhaps only this one thing, that nothing at all is certain.

~ René Descartes

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

~ René Descartes

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

~ René Descartes

although we very clearly see the sun, we ought not therefore to determine that it is only of the size which our sense of sight presents; and we may very distinctly imagine the head of a lion joined to the body of a goat, without being therefore shut up to the conclusion that a chimaera exists; for it is not a dictate of reason that what we thus see or imagine is in reality existent; but it plainly tells us that all our ideas or notions contain in them some truth.

~ René Descartes

Some years ago I was struck by the large number of falsehoods that I had accepted as true in my childhood, and by the highly doubtful nature of the whole edifice that I had subsequently based on them. I realized that it was necessary, once in the course of my life, to demolish everything completely and start again right from the foundations if I wanted to establish anything at all in the sciences that was stable and likely to last.

~ René Descartes

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.

~ René Descartes

And thus, the actions of life often not allowing any delay, it is a truth very certain that, when it is not in our power to determine the most true opinions we ought to follow the most probable.

~ René Descartes

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

~ René Descartes

The dreams we imagine when we are asleep should not in any way make us doubt the truth of the thoughts we have when we are awake.

~ René Descartes

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

~ René Descartes

The reading of all good books is like conversation with the finest men of past centuries.

~ René Descartes

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

~ René Descartes

Thus the perception of the infinite is somehow prior in me to the perception of the finite, that is, my perception of God is prior to my perception of myself. For how would I understand that I doubt and that I desire, that is, that I lack something and that I am not wholly perfect, unless there were some idea in me of a more perfect being, by comparison with which I might recognize my defects?

~ René Descartes

When I turn my mind's eye upon myself, I understand that I am a thing which is incomplete and dependent on another and which aspires without limit to ever greater and better things...

~ René Descartes

...we ought not meanwhile to make use of doubt in the conduct of life.

~ René Descartes

Whence then come my errors? They come from the sole fact that since the will is much wider in its range and compass than the understanding, I do not restrain it within the same bounds, but extend it also to things which I do not understand: and as the will is of itself indifferent to these, it easily falls into error and sin, and chooses the evil for the good, or the false for the true.

~ René Descartes

And, in fine, of false sciences I thought I knew the worth sufficiently to escape being deceived by the professions of an alchemist, the predictions of an astrologer, the impostures of a magician, or by the artifices and boasting of any of those who profess to know things of which they are ignorant.

~ René Descartes

Gratitude is a species of love, excited in us by some action of the person for whom we have it, and by which we believe that he has done some good to us, or at least that he has had the intention of doing so. Passions, III, 193. XI, 473-474. Trans. John Morris

~ René Descartes

...the greater objective (representative) perfection there is in our idea of a thing, the greater also must be the perfection of its cause.

~ René Descartes

For, occupied incessantly with the consideration of the limits prescribed to their power by nature, they [philosophers of former times] 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.

~ René Descartes

I revered our theology, and aspired as much as any one to reach heaven: but being given assuredly to understand that the way is not less open to the most ignorant than to the most learned, and that the revealed truths which lead to heaven are above our comprehension, I did not presume to subject them to the impotency of my reason; and I thought that in order competently to undertake their examination, there was need of some special help from heaven, and of being more than man.

~ René Descartes

...we ought also to consider as false all that is doubtful.

~ René Descartes

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.

~ René Descartes

With me, everything turns into mathematics.

~ René Descartes

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

~ René Descartes

...reading good books is like engaging in conversation with the most cultivated minds of past centuries who had composed them, or rather, taking part in a well-conducted dialogue in which such minds reveal to us only the best of their thoughts

~ René Descartes

[About Pierre de Fermat] It cannot be denied that he has had many exceptional ideas, and that he is a highly intelligent man. For my part, however, I have always been taught to take a broad overview of things, in order to be able to deduce from them general rules, which might be applicable elsewhere.

~ René Descartes

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.

~ René Descartes

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

~ René Descartes

The senses deceive from time to time, and it is prudent never to trust wholly those who have deceived us even once.

~ René Descartes

It is not enough to have a good mind the main thing is to use it well.

~ René Descartes

The reading of all good books is like a conversation with the finest minds of past centuries.

~ René Descartes

I am indeed amazed when I consider how weak my mind is and how prone to error.

~ René Descartes

When it is not in our power to follow what is true, we ought to follow what is most probable.

~ René Descartes

The two operations of our understanding, intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge.

~ René Descartes

A state is better governed which has few laws, and those laws strictly observed.

~ René Descartes

Perfect numbers like perfect men are very rare.

~ René Descartes