Rene Descartes Quotes

These long chains of perfectly simple and easy reasonings by means of which geometers are accustomed to carry out their most difficult demonstrations had led me to fancy that everything that can fall under human knowledge forms a similar sequence; and that so long as we avoid accepting as true what is not so, and always preserve the right order of deduction of one thing from another, there can be nothing too remote to be reached in the end, or to well hidden to be discovered.

But I cannot forget that, at other times I have been deceived in sleep by similar illusions; and, attentively considering those cases, I perceive so clearly that there exist no certain marks by which the state of waking can ever be distinguished from sleep, that I feel greatly astonished; and in amazement I almost persuade myself that I am now dreaming.

It is possible that I am dreaming right now and that all of my perceptions are false.

It is contrary to reasoning to say that there is a vacuum or space in which there is absolutely nothing.

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.

Whenever anyone has offended me, I try to raise my soul so high that the offense cannot reach it.

I can doubt everything, except one thing, and that is the very fact that I doubt. Simply put - I think, therefore I am

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

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

God alone is the author of all the motions in the world.

Even if I were to suppose that I was dreaming and whatever I saw or imagined was false, yet I could not deny that ideas were truly in my mind.

So far, I have been a spectator in this theater which is the world, but I am now about to mount the stage, and I come forward masked.

Whatever I have up till now accepted as most true and assured I have gotten either from the senses or through the senses. But from time to time I have found that the senses deceive, and it is prudent never to trust completely those who have deceived us even once.

We never understand a thing so well,and make it our own, as when we have discovered it for ourselves.

A person has two passions for love and abhorrence. A big disposition to excessiveness has just a love, because it is more ardent and stronger.

Divide each difficulty at hand into as many pieces as possible and as could be required to better solve them.

Doubt is the origin of wisdom

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 th eincreasing discovery of my own ignorance

There is a little gland in the brain in which the soul exercises its functions in a more particular way than in the other parts.

The chief cause of human errors is to be found in the prejudices picked up in childhood.

Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has.

I accept no principles of physics which are not also accepted in mathematics.

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

Truths are more likely to be discovered by one man than by a nation

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

...it is certain that I am really distinct from my body, and can exist without it.

I am thinking, therefore I exist. (...) I was a substance whose whole essence or nature is solely to think, and which does not require any place, or depend on any material thing, in order to exist. Accordingly this 'I' - that is, the soul by which I am what I am - is entirely distinct from the body, and indeed is easier to know than the body, and would not fail to be whatever it is, even if the body did not exist.

With me, everything turns into mathematics.

... moral certainty is certainty which is sufficient to regulate our behaviour, or which measures up to the certainty we have on matters relating to the conduct of life which we never normally doubt, though we know that it is possible, absolutely speaking, that they may be false.

Even those who have the weakest souls could acquire absolute mastery over all their passions if we employed sufficient ingenuity in training and guiding them.

Mathematics is a more powerful instrument of knowledge than any other that has been bequeathed to us by human agency.

All is to be doubted.

I did not imitate the skeptics who doubt only for doubting's sake, and pretend to be always undecided; on the contrary, my whole intention was to arrive at a certainty, and to dig away the drift and the sand until I reached the rock or the clay beneath.

Before examining this more carefully and investigating its consequences, I want to dwell for a moment in the contemplation of God, to ponder His attributes in me, to see, admire, and adore the beauty of His boundless light, insofar as my clouded insight allows. Believing that the supreme happiness of the other life consists wholly of the contemplation of divine greatness, I now find that through less perfect contemplation of the same sort I can gain the greatest joy available in this life.

I experienced in myself a certain capacity for judging which I have doubtless received from God, like all the other things that I possess; and as He could not desire to deceive me, it is clear that He has not given me a faculty that will lead me to err if I use it aright.

On the one hand I have a clear and distinct idea of myself, in so far as I am a thinking, non-extended thing; and on the other hand I have a distinct idea of body, in so far a this is simply an extended, non-thinking thing. And, accordingly, it is certain that I am really distinct from my body, and exist without it.

The only secure knowledge is that I exist.

In philosophy, when we make use of false principles, we depart the farther from the knowledge of truth and wisdom exactly in proportion to the care with which we cultivate them, and apply ourselves to the deduction of diverse consequences from them, thinking that we are philosophizing well, while we are only departing the farther from the truth; from which it must be inferred that they who have learned the least of all that has been hitherto distinguished by the name of philosophy are the most fitted for the apprehension of truth.

Sensations are nothing but confused modes of thinking.

Now therefore, that my mind is free from all cares, and that I have obtained for myself assured leisure in peaceful solitude, I shall apply myself seriously and freely to the general destruction of all my former opinions.

And thereby make ourselves, as it were, the lords and masters of nature.

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

There is a great difference between mind and body insomuch as body is by nature always divisible, and the mind is entirely indivisible.

The principal use of prudence, of self-control, is that it teaches us to be masters of our passions, and to so control and guide them that the evils which they cause are quite bearable, and that we even derive joy from them all.

Nothing comes out of nothing.

I concluded that I might take as a general rule the principle that all things which we very clearly and obviously conceive are true: only observing, however, that there is some difficulty in rightly determining the objects which we distinctly conceive.

In God there is an infinitude of things which I cannot comprehend, nor possibly even reach in any way by thought; for it is the nature of the infinite that my nature, which is finite and limited, should not comprehend it.

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