Rene Descartes
At last I will devote myself sincerely and without reservation to the general demolition of my opinions.Collection: Lasts
All is to be doubted.Collection: Knowing Who You Are
Intuitive knowledge is an illumination of the soul, whereby it beholds in the light of God those things which it pleases Him to reveal to us by a direct impression of divine clearness.Collection: Light
I have concluded the evident existence of God, and that my existence depends entirely on God in all the moments of my life, that I do not think that the human spirit may know anything with greater evidence and certitude.Collection: Philosophy
Give me extension and motion and I will construct the universe.Collection: Math
Science is practical philosophy.Collection: Philosophy
And as it is the most generous souls who have most gratitude, it is those who have most pride, and who are most base and infirm, who most allow themselves to be carried away by anger and hatred.Collection: Gratitude
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.Collection: Way
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.Collection: Believe
With me, everything turns into mathematics.Collection: Math
But in my opinion, all things in nature occur mathematically.Collection: Opinion
It is best not to go on for great quest for truth , it will only make you miserableCollection: Goes On
Few look for truth; many prowl about for a reputation of profundity by arrogantly challenging whichever arguments are the best.Collection: Challenges
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.Collection: Book
It's the familiar love-hate syndrome of seduction: "I don't really care what it is I say, I care only that you like it."Collection: Hate
My third maxim was to try always to conquer myself rather than fortune, and to change my desires rather than the order of the world, and generally to accustom myself to believing that there is nothing entirely in our power except our thoughts, so that after we have done our best regarding things external to us, everything in which we do not succeed is for us absolutely impossible.Collection: Change
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.Collection: Numbers
Nothing comes out of nothing.Collection: Aries
He who hid well, lived well.Collection: Wells
Mathematics is a more powerful instrument of knowledge than any other that has been bequeathed to us by human agency.Collection: Powerful
There is nothing more ancient than the truth.Collection: Ancient
To live without philosophizing is in truth the same as keeping the eyes closed without attempting to open them.Collection: Eye
Your joy is your sorrow unmasked. And the self-same well from which your laughter rises was often-times filled with your tears.Collection: Happiness
It is possible that I am dreaming right now and that all of my perceptions are false.Collection: Dream
I desire to live in peace and to continue the life I have begun under the motto 'to live well you must live unseenCollection: Desire
Desire awakens only to things that are thought possible.Collection: Desire
Intuition is the undoubting conception of a pure and attentive mind, which arises from the light of reason alone, and is more certain than deduction.Collection: Light
If I simply refrain from making a judgment in cases where I do not perceive the truth with sufficient clarity and distinctness, then it is clear that I am behaving correctly and avoiding error.Collection: Errors
Bad books engender bad habits, but bad habits engender good books.Collection: Book
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.Collection: World
For to be possessed of a vigorous mind is not enough; the prime requisite is rightly to apply it.Collection: Mind
Although my knowledge grows more and more, nevertheless I do not for that reason believe that it can ever be actually infinite, since it can never reach a point so high that it will be unable to attain any greater increase.Collection: Believe
Be that as it may, there is fixed in my mind a certain opinion of long standing, namely that there exists a God who is able to do anything and by whom I, such as I am, have been created. How do I know that he did not bring it about that there is no earth at all, no heavens, no extended thing, no shape, no size, no place, and yet bringing it about that all these things appear to me to exist precisely as they do now?Collection: Long
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.Collection: Thinking
What then is the source of my errors? They are owing simply to the fact that, since the will extends further than the intellect, I do not contain the will within the same boundaries; rather, I also extend it to things I do not understand. Because the will is indifferent in regard to such matters, it easily turns away from the true and the good; and in this way I am deceived and I sin.Collection: Errors
The object of music is a Sound. The end; to delight, and move various Affections in us.Collection: Music
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.Collection: Rocks
When writing about transcendental issues, be transcendentally clear.Collection: Writing
Just as we believe by faith that the greatest happiness of the next life consists simply in the contemplation of this divine majesty, likewise we experience that we derive the greatest joy of which we are capable in this life from the same contemplation, even though it is much less perfect.Collection: Believe
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.Collection: Dream
Common sense is the best distributed thing in the world, for we all think we possess a good share of it.Collection: Thinking
For each of us there is a set limit to our intellectual powers which we cannot pass.Collection: Encouragement
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.Collection: Passion
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.Collection: Thinking
Neither the true nor the false roots are always real; sometimes they are imaginary; that is, while we can always imagine as many roots for each equation as I have assigned, yet there is not always a definite quantity corresponding to each root we have imagined.Collection: Real
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.Collection: Deceived Us
We call infinite that thing whose limits we have not perceived, and so by that word we do not signify what we understand about a thing, but rather what we do not understand.Collection: Ontology
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.Collection: Passion
And I shall always hold myself more obliged to those by whose favour I enjoy uninterrupted leisure than to any who might offer me the most honourable positions in the world.Collection: Life