Meditations on the First Philosophy

by René Descartes

It is now several years since I noticed how from the time of my early youth I had accepted many false claims as true, how everything I had later constructed on top of those [falsehoods] was doubtful, and thus how at some point in my life I needed to tear everything down completely and begin again from the most basic foundations, if I wished to establish something firm and lasting in the sciences. But this seemed an immense undertaking, and I kept waiting, until I would be old enough and sufficiently mature to know that no later period of my life would come [in which I was] better equipped to undertake this disciplined enquiry. This reason made me delay for so long, that I would now be at fault if, by [further] deliberation, I used up the time which still remains to carry out that project. And so today, when I have conveniently rid my mind of all worries and have managed to find myself secure leisure in solitary withdrawal, I will at last find the time here for an earnest and unfettered general demolition of my [former] opinions.

Thus, from these facts perhaps we are not reaching an erroneous conclusion [by claiming] that physics, astronomy, medicine, and all the other disciplines which rely upon a consideration of composite objects are indeed doubtful, but that arithmetic, geometry, and the other [sciences] like them, which deal with only the simplest and most general matters and have little concern whether or not they exist in the nature of things, contain something certain and indubitable. For whether I am awake or asleep, two and three always add up to five, a square does not have more than four sides, and it does not seem possible that such manifest truths could ever arouse the suspicion that they are false.

Nevertheless, a certain opinion has for a long time been fixed in my mind—that there is an all-powerful God who created me and [made me] just as I am. But how do I know He has not arranged things so that there is no earth at all, no sky, no extended thing, no shape, no magnitude, no place, and yet seen to it that all these things appear to me to exist just as they do now?

But this task is onerous, and a certain idleness brings me back to my customary way of life. I am not unlike a prisoner who in his sleep may happen to enjoy an imaginary liberty and who, when he later begins to suspect that he is asleep, fears to wake up and willingly cooperates with the pleasing illusions [in order to prolong them]. In this way, I unconsciously slip back into my old opinions and am afraid of waking up, in case from now on I would have to spend the period of challenging wakefulness that follows this peaceful relaxation not in the light, but in the inextricable darkness of the difficulties I have just raised.

Provisions for existential thoughts.

I will reject everything which admits of the slightest doubt, just as if I had discovered it was completely false, and I will proceed further in this way, until I find something certain, or at least, if I do nothing else, until I know for certain that there is nothing certain.

Therefore, I assume that everything I see is false. I believe that none of those things my lying memory represents has ever existed, that I have no senses at all, and that body, shape, extension, motion, and location are chimeras.[xiii] What, then, will be true? Perhaps this one thing: there is nothing certain.

Still, I am puzzled, for what follows from this? Am I so bound up with my body and my senses that I cannot exist without them? But I have convinced myself that there is nothing at all in the universe—no sky, no earth, no minds, no bodies. So then, is it the case that I, too, do not exist? No, not at all: if I persuaded myself of something, then I certainly existed. But there is some kind of deceiver, supremely powerful and supremely cunning, who is constantly and intentionally deceiving me. But then, if he is deceiving me, there is no doubt that I, too, for that very reason exist. Let him trick me as much as he can, he will never succeed in making me nothing, as long as I am aware that I am something. And so, after thinking all these things through in great detail, I must finally settle on this proposition: the statement I am, I exist is necessarily true every time I say it or conceive of it in my mind.

What about thinking? Here I discover something: thinking does exist. This is the only thing which cannot be detached from me. I am, I exist—that is certain. But for how long? Surely for as long as I am thinking. For it could perhaps be the case that, if I were to abandon thinking altogether, then in that moment I would completely cease to be. At this point I am not agreeing to anything except what is necessarily true. Therefore, strictly speaking, I am merely a thinking thing, that is, a mind or spirit, or understanding, or reason—words whose significance I did not realize before. However, I am something real, and I truly exist. But what kind of thing? As I have said, a thing that thinks.

But what then am I? A thinking thing. What is this? It is surely something that doubts, understands, affirms, denies, is willing, is unwilling, and also imagines and perceives.

And behold—I have all on my own finally returned to the place where I wanted to be. For since I am now aware that bodies themselves are not properly perceived by the senses or by the faculty of imagination, but only by the intellect, and are not perceived because they are touched or seen, but only because they are understood, I realize this obvious point: there is nothing I can perceive more easily or more clearly than my own mind. But because it is impossible to rid oneself so quickly of an opinion one has long been accustomed to hold, I would like to pause here, in order to impress this new knowledge more deeply on my memory with a prolonged meditation.

However, the most important point I have to explore here concerns those ideas which I think of as being derived from objects existing outside me: What reason leads me to suppose that these ideas are similar to those objects?

After that, by examining myself more closely and looking into the nature of my errors (the only things testifying to some imperfection in me), I observe that they proceed from two causes working together simultaneously, namely, from the faculty of knowing, which I possess, and from the faculty of choosing, or from my freedom to choose, in other words from both the intellect and the will together.

Clearly divine grace and natural knowledge never diminish liberty, but rather increase and strengthen it.

For these reasons, however, I perceive that the power of willing, which I have from God, considered in itself, is not the source of my errors. For it is extremely spacious and a perfect example of its kind. And the source is not my power of understanding. For when I understand something, I undoubtedly do so correctly, since my [power of] understanding comes from God, and thus it is impossible for it to deceive me. So from where do my errors arise? Surely from the single fact that my will ranges more widely than my intellect, and I do not keep it within the same limits but extend it even to those things which I do not understand. Since the will does not discriminate among these things, it easily turns away from the true and the good, and, in this way, I make mistakes and transgress.

perception of the understanding must always precede a determination of the will.

For obviously it is not an imperfection in God that He has given me freedom to assent or not to assent to certain things, when He has not placed a clear and distinct perception of them in my understanding. However, it is undoubtedly an imperfection in me that I do not use that liberty well and that I bring my judgment to bear on things which I do not properly understand. Nonetheless, I see that God could easily have created me so that I never made mistakes, even though I remained free and had a limited understanding. For example, He could have placed in my intellect a clear and distinct perception of everything about which I would ever deliberate, or He could have impressed on my memory that I should never make judgments about things which I did not understand clearly and distinctly, and done that so firmly that it would be impossible for me ever to forget. And I readily understand that, if God had made me that way, insofar as I have an idea of this totality, I would have been more perfect than I am now. But I cannot therefore deny that there may somehow be more perfection in this whole universe of things because some of its parts are not immune to errors and others are, than if all things were entirely alike. And I have no right to complain just because the part God wanted me to play in the universe is not the most important and most perfect of all.

For although experience teaches me that I have a weakness which renders me incapable of keeping [my mind] always focused on one and the same thought, I can still see to it that by attentive and frequently repeated mediation I remember that fact every time the occasion demands. In this way I will acquire the habit of not making mistakes.

Since the greatest and preeminent perfection of human beings consists in this ability to avoid mistakes, I think that with the discovery in today’s meditation of the cause of error and falsity I have gained a not inconsiderable gift.

And this necessity is obviously sufficient to make me conclude correctly, once I have recognized that existence is a perfection, that a first and supreme being exists. In the same way, it is not necessary that I ever imagine any triangle, but every time I wish to consider a rectilinear figure with only three angles, I have to attribute to it those [properties] from which I correctly infer that its three angles are no greater than two right angles, although at that time I may not notice this.

For although my nature is such that, as long as I perceive something really clearly and distinctly, I am unable to deny that it is true, nevertheless, because I am also by nature incapable of always fixing my mental gaze on the same thing in order to perceive it clearly, [and because] my memory may often return to a judgment I have previously made at a time when I am not paying full attention to the reasons why I made such a judgment, other arguments can present themselves which, if I knew nothing about God, might easily drive me to abandon that opinion. Thus, I would never have any true and certain knowledge, but merely vague and changeable opinions.

However, after I perceived that God exists, because at the same time I also realized that all other things depend on Him and that He is not a deceiver, I therefore concluded that everything I perceive clearly and distinctly is necessarily true. Thus, even if I am not fully attending to the reasons why I have judged that something is true, if I only remember that I have perceived it clearly and distinctly, no opposing argument can present itself that would force me to have doubts. Instead, I possess true and certain knowledge about it—and not just about that, but about all other matters which I remember having demonstrated at any time,

To these reasons for doubting sense experience, I recently added two extremely general ones. First, there was nothing I ever thought I was sensing while awake that I could not also think I was sensing now and then while asleep, and since I do not believe that those things I appear to sense in my sleep come to me from objects placed outside me, I did not see why I should give more credit to those I appear to sense when I am awake. Second, because I was still ignorant—or at least was assuming I was ignorant—of the author of my being, there seemed to be nothing to prevent nature from constituting me in such a way that I would make mistakes, even in those matters which seemed to me most true.

Now, when I consider the intended purpose of the clock, I could say that, since it does not indicate the time correctly, it is deviating from its own nature, and, in the same way, when I think of the machine of the human body as something formed for the motions which usually take place in it, I might believe that it, too, is deviating from its own nature, if its throat is dry when a drink does not benefit its own preservation. However, I am fully aware that this second meaning of the word nature is very different from the first. For it is merely a term that depends on my own thought, a designation with which I compare a sick person and a badly constructed clock with the idea of a healthy person and a properly constructed clock, and thus, the term is extrinsic to these objects. But by that [other use of the term nature] I understand something that is really found in things and that therefore contains a certain measure of the truth.