Meditation One:
"Concerning Those Things That Can Be Called Into Doubt"
The Meditations consists of meditations "on First Philosophy". In the Preface to the French edition of the Principles of Philosophy in 1647, Descartes explains that by "First Philosophy" he means metaphysics. Here he provides a simile: philosophy is like a tree, with metaphysics as the roots, physics as the trunk, and the various sciences (principally medicine, mechanics and morals) as the branches.
"The first part of philosophy is metaphysics, which contains the principles of knowledge, including the explanation of the principal attributes of God, the non-material nature of our souls and all the clear and distinct notions which are in us. The second part is physics, where, after discovering the true principles of material things, we examine the general composition of the entire universe and then, in particular, the nature of this earth and all the bodies which are most commonly found upon it, such as air, water, fire, magnetic ore and other minerals. Next we need to examine individually the nature of plants, of animals and, above all, of man, so that we may be capable later on of discovering the other sciences which are beneficial to man. Thus the whole of philosophy is like a tree. The roots are metaphysics, the trunk is physics, and the branches emerging from the trunk are all the other sciences, which may be reduced to three principal ones, namely medicine, mechanics and morals." (CSM I, p. 186)
The task of the Meditations, then, is to provide a metapysics that will be a foundation for the sciences. As he says in Meditation I:
"I had to raze everything to the ground and begin again from the original foundations, if I wanted to establish anything firm and lasting in the sciences". (p. 27)
Descartes has to "raze everything to the ground" because he has come to realize that in his youth he acquired "false opinions" about the world and built upon them. Since he cannot go through all of his opinions one by one to determine which are true and which are false (it would take too long and might even be impossible, in practice), he will attack the general principles on which he arrived at his beliefs about the world:
"I will attack straightaway those principles which supported everything I once believed." (p. 28)
The general principle on which he based his beliefs about the world was: whatever the senses 'told' him about the world was true:
"whatever I had admitted until now as most true I received either from the senses or through the senses." (p. 28)
(If you were asked why you believe that it is true that, e.g., there is a desk in front of you, you would respond, "Because I see it". So your belief is based upon or derived from your sense perception of a desk. And in general, all, or the vast majority, of the things that you believe to be true, you believe to be true because of the sense perceptions that you have. So the principle on which your beliefs rest is: SENSE PERCEPTION IS RELIABLE.
It should be pointed out that Descartes's attack on the senses will NOT have the result that everything that the senses tell us is false. Some things that the senses tell us -- e.g. that bodies have colors -- are false. Other things that the senses tell us -- e.g. that bodies exist -- are true. The point is that the new principle on which our true beliefs will rest will not be the principle of the reliability of sense perception. This new principle will not lead to any false beliefs whatsoever.)
Meditation I, therefore, consists of a sustained attack on the principle of the reliability of the senses. Essentially, Descartes applies his intellect to the principle of the reliability of the senses, to determine how far he can doubt this principle.
However, it is important to note that by the end of Meditation I, Descartes doubts not merely his senses, but his own reasoning about matters that are independent of his senses, such as arithmetic and geometry. Thus, the doubts of Meditation are not only directed at the senses.
The point of doubting, however, is to arrive at that which cannot be doubted. The point of doubt is to arrive at certainty.
There are six doubts, or levels of doubt, in Meditation I. They are:
(1) Deceptive Senses Argument
(2) Dream Argument
(3) Extreme Dream Argument
(4) Possibly Deceiving God Argument
(5) Actually Deceiving God Argument
(6) Product of Chance Argument
It should be noted that doubts (1)-(3) concern the senses, whereas doubts (4)-(6) concern reasoning itself.
(1) Deceptive Sense Perception Argument
"the senses do sometimes deceive us when it is a question of very small and distant things" (p. 28)
Sense perceptions are sometimes deceptive. For example, if the light is poor, or the object is far away. So the senses are not always reliable.
(Note: Descartes does not make the mistake here of arguing that if sense perceptions are sometimes deceptive then they are always deceptive. That would be to argue that if they are sometimes, i.e. not always, deceptive, then are always deceptive! The argument here is merely that sense perceptions are sometimes deceptive, i.e. that they are not always reliable.)
Reply to (1)
Sense perceptions are always reliable in ideal conditions of observation (broad daylight, close-up, etc.). Sense deceptions are only unreliable in non-ideal conditions of observation.
(Note: This entails that sense perceptions in ideal conditions of observation can be used to correct beliefs based upon sense perceptions in poor conditions of observation.
In addition, it may be argued that some sense perceptions may be used to correct other sense perceptions in either poor or ideal conditions of observation. For example, even in poor light, I can reach out to touch the object in front of me to determine if it is a dog or merely a shadow. The sense of touch can correct the sense of sight here. The same can be said for the illusion of a bent-looking stick in clear water. Touch determines that the stick is straight, not bent.)
(2) Dream Argument
"How often does my evening slumber persuade me of such ordinary things as these: that I am here, clothed in my dressing gown, seated next to the fireplace – when in fact I am lying undressed in bed!... I see plainly that there are no definitive signs by which to distinguish being awake from being asleep" (p. 28)
It is possible that 'sense perceptions' in ideal conditions of observation may be deceptive, because they may not be sense perceptions at all, but dreams.
(Note: this argument is not so much an argument that sense perceptions are not reliable, as that we may not be having sense perceptions when we think we are having them. That is, Descartes is not arguing that even if we are awake, we may be deceived. Rather he is arguing that we may not be awake.
So the argument may be put: Yes, it is true that sense perceptions in ideal conditions are always reliable, but how do I know that I am having sense perceptions in ideal conditions, and not dreaming?
The argument might be put differently by selecting a neutral term, such as 'images (etc.)', so that the argument would be: Images (etc.) in ideal conditions of observation may be deceptive, because I may be dreaming, and not having a sense perception.
This would be to argue against the position that: Images (etc.) in ideal conditions of observation are always reliable (as opposed to: sense perceptions in ideal conditions of observation are always reliable.))
One way (not the only way, and not, probably, the correct way) of putting the Dream Argument is as follows:
Dream Argument (bad version)
(1) I sometimes have dreams that are exactly like sense perceptions.
(2) If I sometimes have dreams that are exactly like sense perceptions, then I cannot distinguish with certainty between sense perceptions and dreams.
(3) So, I cannot distinguish with certainty between sense perceptions and dreams.
(4) If I cannot distinguish with certainty between sense perceptions and dreams, then I cannot believe as true anything based on sense perceptions.
––> I cannot believe as true anything based on sense perceptions.
However, if the argument is put this way, it self-refuting. Premise (1) above entails that I am already able to distinguish between dreams and sense perceptions while they are occurring. That is, premise (1), fully unpacked, is the premise that:
(1) I sometimes have dreams [which I know are dreams, and not sense perceptions] that are exactly like sense perceptions.
That is, I have dreams, and I know at the time that they are dreams, and not sense perceptions, and I also have sense perceptions, and I know at the time that they are sense perceptions, and not dreams, and when I compare the two, I see that the dreams are exactly like the sense perceptions. But if this is what premise (1) means or entails when it is unpacked, then it cannot be used to support an argument with the conclusion that I cannot distinguish between dreams and sense perceptions! The argument would be self-refuting.
To avoid being self-refuting, the Dream Argument may be put as follows:
Dream Argument (good version)
(1*) If I cannot distinguish with certainty between sense perceptions and dreams, then I cannot believe as true anything based on images, etc.
(2*) I cannot distinguish with certainty between sense perceptions and dreams.
––> I cannot believe as true anything based on images, etc.
This argument is valid. The question that remains is whether the argument is sound, i.e. whether all of the premises are true.
Let us grant for now that premise (1*) is true. It remains to be seen whether premise (2*) is true.
It might be argued that I can at least know after a dream that it was a dream and not a sense perception, because it was vague, indistinct, disordered, and contained physical impossibilities (etc.). One question this raises is: Why, then, I can't know, during a dream, that I am having a dream? If it is clearly such a chaotic experience, surely I can recognize its being a dream while I am having it? Why can I only realize this afterwards?
However, dreams can be vivid, distinct, ordered, and contain no physical impossibilities (etc.) Hence, even if we had the ability to detect that we were having a dream because it was a chaotic dream, that would leave us powerless in the face of ordered dreams.
It is indeed true that, because of such ordered dreams, we can wonder whether we had those sense perceptions or whether we merely dreamt it. So, at least sometimes, we don't know after a dream (at least, not immediately) that it was a dream.
More troublingly, for all we know, there are two dream cycles. Call the first, the one that we normally refer to as "dreaming" and that can be chaotic or ordered, dreaming. Call the second, the one that we normally refer to as "waking experience" super-dreaming. For all we know, we alternate between dreaming and super-dreaming all the time, and never actually have sense perceptions. We 'wake up' from dreaming, but just to start super-dreaming. So we never actually wake up.
Consider, for example, the movie The Matrix. People in the matrix have two dream lives, not one. On the one hand, they super-dream that they are living in NYC in the late 20th century. On the other hand, when they 'come home from work' and 'fall asleep' (i.e. when they super-dream that they fall asleep), they dream the kind of dreams that we also dream --- that they are climbing Mt. Everest, or standing naked in the middle of a crowd, or whatever. After a while they 'wake up' from their dreaming to the super-dream of being in NYC in the 20th century. But really they are in mechanical pods in the 23rd century, super-dreaming that they are living in NYC in the 20th century, and within that super-dream, dreaming that they are dreaming about climbing Mt. Everest, etc.
The important point here is that a dream is not a dream because of its content. A dream is not a dream because of anything internal to it.
A dream is a dream because of external conditions that make it a dream and not a sense perception. If I am asleep and having an image of X, then I am dreaming. If I am awake and having a image of an X, then I am not dreaming, whatever else I am doing. (Usually I am having a sense perception, but I could also be having a hallucination or seeing a mirage.) Dreaming is a certain kind of state. The only way to know that I am not dreaming or super-dreaming is to know that I am not in a state of being asleep and having mental images, sounds, etc., and no amount of images, sounds, etc., can tell me that I am not in a state of being asleep and having images, sounds, etc., before my mind.
Arguably, then, premise (2*) is true. I can never be certain that I am not dreaming (or super-dreaming), as opposed to having a sense perception. I can never step outside of myself to check to see what state I am in. It is indeed possible that I am dreaming (or super-dreaming).
Descartes, however, has a very different kind of reply to the Dream Argument. He does not challenge premise (2*) at all. Instead he challenges premise (1*): If I cannot distinguish with certainty between sense perceptions and dreams, then I cannot believe as true anything based on images, etc.
Reply to (2)
"Nevertheless, it surely must be admitted that the things seen during slumber are, as it were, like pained images, which could only have been produced in the likeness of true things, and that these general things -- eyes, head, hands, and the whole body -- are not imaginary things, but are true and exist." (p. 28)
This is actually a very clever reply. The reply is that the contents of dreams (Mt. Everest, other people, buildings, etc.) must come from reality. Images, etc., are drawn from the world. So even if I am dreaming, I know that there are mountains, other people, buildings, etc. They must exist in order for me to have dreams like the ones I have. If the world were different, I would have different kinds of dreams. But I don't, and it's not. The contents of dreams are taken from reality.
The reply to this might be that the contents of our dreams might be just as imaginary as, say unicorns.
Descartes's reply would be to say that even unicorns are composed of parts taken from reality -- e.g. horse's body, narwhal's horn. So I know that those parts really do exist. I can be certain of that. As he says "these general things -- eyes, head, hands, and the whole body -- are... true and exist", even if they are recycled into creatures.
Another way of putting this would be to say that although the world of The Matrix is a dream, it is composed of images, etc., that are taken from reality (at the very least, those buildings, bodies, etc., once existed).
(This argument is actually quite a strong one, in the following sense. Dreams are merely recycled sense perceptions. No image, sound, smell, etc., that occurs in a dream is an original. It is always either a sense perception, or a combination of sense perceptions, or a combination of elements of sense perceptions. Sense perceptions can be original because it is always possible to have a new experience (maybe even: every experience is a new experience.) Why is this true? Simply because it is not possible for someone to create an image, sound, smell, etc., from nothing. It is not possible to simply invent one. One can of course combine and re-combine and add and subtract them, but not invent one. So, a world, and not me, is providing me with images, sounds, smells, etc.)
Hence, even if I am dreaming, dreams are reliable. They do tell us what really exists, or what really existed. They are not mere inventions. The world is either exactly as it is in dreams, or at least, is composed of parts that are exactly as they are in dreams.
So premise (1*) is false. It is false that: If I cannot distinguish with certainty between sense perceptions and dreams, then I cannot believe as true anything based on images, etc.
Thus the Dream Argument is unsound. It is not unsound because it is not possible that I am dreaming (or super-dreaming). It is possible that I am dreaming (or super-dreaming). However, the doubt was never directed at dreaming itself. The doubt was directed at beliefs formed while I was dreaming. If it is true that all dreams are made up of contents that are taken from reality, then beliefs about the world that are formed in dreams are true. So I don't have to worry if I am dreaming or not.
(3) Extreme Dream Argument
"these general things -- eyes, head, hands and the like -- could be imaginary" (p. 28)
The contents of dreams are not taken from reality. Dreams have no basis in reality whatsoever. That is, there are no eyes, or heads, or hands, or whole bodies in existence, from which the dream is composed. There are no buildings, no mountains, etc., from which my dreams are composed.
Another way of putting this is to say that the dream-world truly is an invention.
Hence, premise (1*) of the Dream Argument is true. It is true that: If I cannot distinguish with certainty between sense perceptions and dreams, then I cannot believe as true anything based on images, etc.
Reply to (3)
"still one has to admit that at least certain other things that are even more simple and universal are true... This class of things appears to include corporeal nature in general, together with its extension; the shape of extended things; their quantity, that is, their size and number; as well as the place where they exist; the time through which they endure, and the like." (p. 28)
"arithmetic, geometry, and other such disciplines, which treat of nothing but the simplest and most general things and which are indifferent as to whether these things do or do not exist, contain something certain and indubitable. For whether I am awake or asleep, two plus three make five, and a square does not have more than four sides." (p. 29)
This is again a very clever reply. The argument is that even if dreams were complete inventions, nevertheless even in the case of an invention, there are certain universal categories that remain true. These are the categories that do not require the existence of anything in order to be true. Arithmetic, geometry, and other abstract sciences, do not require the existence of e.g. squares, or numbers, for their truths to be true. Even in a dream, those concepts remain intact, and the truths about them remain intact. Even if I am dreaming, 2 + 3 = 5. No numbers need to exist in order for that truth to be true.
So, even if I am dreaming, I can rely on those truths. In that sense, dreams are reliable. Our arithmetic and geometry remain true even if we are dreaming (or super-dreaming) all the time.
It is important to note here that the reliability of the senses has now been abandoned as a principle for arriving at true beliefs, however.
The truths that Descartes is talking about here are known to be true a priori, that is, entirely independently of experience. No image, etc., ever tells me that 2 + 3 = 5.
The argument that Descartes is rejecting is the following, which is different from the Dream Argument given above:
(1*) If I cannot distinguish with certainty between sense perceptions and dreams, then I cannot believe anything as true.
(2*) I cannot distinguish with certainty between sense perceptions and dreams.
––> I cannot believe anything as true.
Descartes rejects this argument, since he considers premise (1*) to be false. There are some truths that I can know even if I am dreaming. Such truths include those of arithmetic and geometry. This is to say that truths of arithmetic and geometry are impervious to any doubt based on the possibility that I may be dreaming. It is not possible that I am deceived in my reasoning about these matters.
(4) Possibly Deceiving God Argument
"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 extended thing, no shape, no size, no place... may I not... be deceived every time I add two and three or count the sides of a square, or perform an even simpler operation, if that can be imagined?" (p. 29)
It is possible that God has created me in such a way that even when I reason about arithmetic and geometry, etc., I am in error. It is possible that it is not true that 2 + 3 = 5, or that a square has four sides.
(This doubt assumes that God exists.)
(1) God exists.
(2) God created me.
(3) God may be a deceiver.
––> I may be deceived when I reason about matters of arithmetic and geometry.
Reply to (4)
"he is said to be extremely good" (p. 461)
God would never deceive me because it is always wrong to deceive and God is extremely good and thus would never deceive me. So I need not worry about my reasoning in these matters (e.g. arithmetic and geometry). It is not possible that I am deceived about these matters.
This reply assumes that God exists. It rejects as false premise (3) of the argument of Doubt 4. It is false that God may be a deceiver.
(5) Actually Deceiving God Argument
"if it were repugnant to his goodness to have created me such that I be deceived all the time, it would also seem foreign to that same goodness to permit me to be deceived even occasionally. But [I am deceived occasionally, so] we cannot make this last assertion." (p. 29)
This is the argument that we know that we are deceived on occasion, and we know that God is our creator, so it seems as if God has created us in such a way that we are deceived. So God does indeed deceive us, or allows us to be deceived, about certain matters. Therefore, he may indeed deceive us, or allow us to be deceived, when reasoning in these matters (e.g. arithmetic and geometry). So it is possible that I am deceived in my reasoning about these matters.
(1) God exists.
(2) God created me.
(3) I am deceived about certain matters.
(4) So, God deceives me, or allows me to be deceived, about certain matters.
(5) So, God is a deceiver.
(6) So, God may deceive me, or allow me to be deceived, when I reason about matters of arithmetic and geometry.
––> I may be deceived when I reason about matters of arithmetic and geometry.
(This doubt assumes that God exists.)
Two replies to (5)
(a) Assume God exists
"I have nothing to say in response to [this argument]... I am forced to admit that there is nothing among the things I once believed to be true which it is not permissible to doubt" (p. 29)
Here Descartes says that, assuming God exists, he cannot see any false premise in the argument that is Doubt 5. His previous argument that God is not a deceiver appears to be have been undermined by the fact of his being deceived (i.e. making mistakes) on many occasions, something that God has orchestrated or at least allowed. The argument appears valid, and thus he must accept the conclusion. If God exists, I must accept that it is indeed possible that I am deceived in my reasoning about matters of arithmetic and geometry.
(b) Do not assume that God exists
"deny so powerful a God... grant that everything said here about God is fictitious." (p. 29)
This is to reject premises (1), (2), (4), (5) and (6) of the argument that is Doubt 5. God does not exist. Since the actuality of a deceiving God was the only reason for doubting the truths of arithmetic and geometry, I need not worry about my reasoning in matters of arithmetic and geometry.
(6) Product of Chance Argument
"suppose that I came to be what I am either by fate, or by chance, or by a connected chain of events, or by some other way. But because being deceived and being mistaken appear to be a certain imperfection, the less powerful they take the author of my origin to be, the more probable it will be that I am so imperfect that I am always deceived." (p. 29)
If God does not exist, then I am simply the product of chance. No intelligence was guiding the creation of me. So it is possible that I am defective. It is possible that I am deceived when reasoning in these matters (arithmetic and geometry).
(1) If I am the product of chance, not design, then I am imperfect.
(2) I am the product of chance, not design.
(3) I am imperfect.
(4) If I am imperfect, then I may be deceived when I reason about matters of arithmetic and geometry.
––> I may be deceived when I reason about matters of arithmetic and geometry.
Reply to (6)
"I have nothing to say in response to [this argument]... I am forced to admit that there is nothing among the things I once believed to be true which it is not permissible to doubt" (p. 29)
Here Descartes says that, assuming that there is no God -- that is, assuming that premise (2) is true -- he cannot see any other false premise in the argument that is Doubt 6. The argument appears valid, and thus he must accept the conclusion. If God does not exist and I am the product of chance, not design, I must accept that I may be deceived in my reasoning about matters of arithmetic and geometry.
So, on this argument, God does not exist, but precisely because of this -- because I am the product of chance -- I may be deceived in reasoning about these matters of arithmetic and geometry.
Summary of Doubts 5 and 6:
If God exists, He is a deceiver, and so it is possible that I am deceived in reasoning about these matters of arithmetic and geometry. And if God does not exist, then I am merely the product of chance, and so it is possible that I am deceived in reasoning about these matters of arithmetic and geometry. Either way, it is possible that I am deceived in reasoning about these matters of arithmetic and geometry.
This argument may be put in the following form:
(1) If God exists, then God is a deceiver.
(2) If God is a deceiver, then I may be deceived in my reasoning.
(3) If God does not exist, then I am the product of chance.
(4) If I am the product of chance, then I may be deceived in my reasoning.
––> I may be deceived in my reasoning.
This argument may be reduced to the following, much simpler argument:
(1*) If God exists, then I may be deceived in my reasoning.
(2*) If God does not exist, then I may be deceived in my reasoning.
––> I may be deceived in my reasoning.
This argument is certainly valid. The question is whether it is sound, that is, whether both premises are true.
What Descartes will argue, eventually, is that premise (1*) is false. He will argue that it is not possible for God to be a deceiver, and hence, that it is false that, if God exists, I may be deceived in my reasoning.
In Meditation III he argues that God is not a deceiver, and in Meditation IV he argues that although I do indeed make mistakes, and thus am 'deceived', nevertheless it is false that God deceives me or even allows me to be deceived. Hence He is not a deceiver even though on occasion I am deceived.
It is important to note that Descartes does not challenge premise (2*) in the Meditations. He doesn't do this because he holds that premise (2*) is true! If indeed there is no God, then I may be deceived in my reasoning.
However, it is important to understand that premise (2*), while true, is irrelevant. Descartes will argue against the possibility that God does not exist. He will argue that "God does not exist" is a contradiction in terms. From a contradiction in terms, anything can follow. So we needn't ever worry about what will follow from a contradiction in terms.
For example, if it is true that:
"If the Pope is a Protestant, then I am a monkey's uncle"
Well, I needn't be worried in the slightest about being a monkey's uncle. This is because it is impossible that the Pope be (a) the Pope and (b) a Protestant. A Protestant Pope is a contradiction in terms.
So even if Descartes accepts premise (2*), he needn't worry about it in the slightest.
Final Device: The "Evil Demon"
Descartes finishes the first Meditation by granting that he has "valid and considered reasons" (p. 29) for doubting all of his previously held beliefs. These are the reasons given above -- either there is a deceiving God, or he is the product of chance. Wanting, as he does, not to believe anything that is false, he says that:
"Nor will I ever get out of the habit of assenting to them [his previously held beliefs], so long as I take them to be exactly what they are, namely, in some respects doubtful, as has just now been shown, but nevertheless highly probable, so that it is much more consistent with reason to believe them than to deny them." (p. 29)
In order to fully guard against believing falsehoods, he will have to go further than merely entertaining the doubt that his previously held beliefs are false, however. He will have to "deceive" himself, to "pretend" that his beliefs are not merely doubtful, but that they are in fact false.
"Hence, it seems to me I would do well to deceive myself by turning my will in completely the opposite direction and pretend for a while that these opinions are wholly false and imaginary... For indeed I know that meanwhile there is no danger or error in following this procedure" (p. 29)
It is important to see here that Descartes is merely coming up with a device to help him believe that all of his previously beliefs are false. He is not saying that they are false. He has reasons to believe that they may be false. But now he gives himself a reason -- he invents a reason -- to believe that they are all false. He "supposes" there exists all-powerful, supremely clever evil genius, a deceiver, who is deceiving him.
"Accordingly, I will suppose... an evil genius, supremely powerful and clever, who has directed his entire effort at deceiving me. I will regard the heavens, the air, the earth, colors, shapes, sounds, and all external things as nothing but the bedeviling hoaxes of my dreams, with which he lays snares for my credulity. I will regard myself as not having hands, or eyes, or flesh, or blood, or any senses, but as nevertheless falsely believing that I possess all these things" (p. 29)
There remains one important question about this invention, the Evil Demon, which will help him in his search for truth. Descartes does not mention the truths of arithmetic and geometry when he describes the false beliefs that the Evil Demon gives him. Does this mean that he does not grant the Evil Demon the power to make him reason incorrectly in matters of arithmetic and geometry? This is a far cry from admitting that there is "nothing" that is not permissible to doubt.