PHILOSOPHY 2A Metaphysics and Classics in Philosophy 1999-2000

Rae Langton
e-mail: Rae.Langton@ed.ac.uk
Phone: 650 3654

This is a guide to Descartes' Meditations, for Philosophy 2A, Spring Term Weeks 1-3. No previous familiarity with the Meditations is assumed. It should be read in conjunction with the text, which is John Cottingham's translation of Descartes' Meditations on First Philosophy, with Selections from the Objections and Replies (Cambridge: Cambridge University Press, 1986). And it should be read in conjunction with the Philosophy 2A Course Guide at the address

http://www.arts.ed.ac.uk/philosophy/study_html/vade-mecum/sections/section5/2a.htm

(You can also get there via the University and Philosophy Department websites; just follow the links. The Philosophy 2A Course Guide will also be on the notice board at the Philosophy Department DHT second floor). It provides details of 2A as a whole, and also of the readings, tutorial topics, and essay topics for the Meditationsin particular.

This Study Guide is in three parts, to make access easier:

Part I is an Introduction and guide to the First Meditation.
Part II is a guide to the Second and Third Meditations.
Part III is a guide to the Fourth, Fifth and Sixth Meditations.

The Study Guide is made available on the assumption that fair use will be made of it. Unacknowledged quotation or paraphrase does not constitute fair use of this, or any other, secondary material and is severely penalized (see 'plagiarism' in Philosophy 2A Study Guide Section IV).

DESCARTES' MEDITATIONS: Part II

SECOND MEDITATION
The nature of the human mind, and how it is better known than the body

The point is found in what is now a very famous argument: cogito ergo sum. This formulation of the argument is from the version in Descartes' Discourse on Method: '[T]his truth 'I am thinking, therefore I exist' [is] so solid and secure that the most extravagant suppositions of the sceptics could not overthrow it'. In the Meditations he puts the argument like this.

I have convinced myself that there is absolutely nothing in the world, no sky, no earth, no minds, no bodies. Does it now follow that I too do not exist? No: if I convinced myself of something then I certainly existed. But there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me. In that case I too undoubtedly exist, if he is deceiving me; and let him deceive me as much as he can, he will never bring it about that am nothing so long as I think I am something. So after considering everything very thoroughly, I must finally conclude that the proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind (25).

What kind of an argument is this? Is it strictly an argument at all? The traditional formulation, 'I think, therefore I am' looks like an argument in every way: it has a premise ('I think'), a 'therefore' indicating an inference, and a conclusion ('I am'). On the other hand, Descartes says in reply to the Second Objections:

When we observe that we are thinking beings, this is a sort of primary notion, which is not the conclusion of any syllogism; and, moreover, when somebody says; I am thinking, therefore I am or exist, he is not using a syllogism to deduce his existence from his thought, but recognizing this as something self-evident, in a simple mental intuition (140).

Descartes' readers have disagreed about whether the cogito is an inference, or a simple 'intuition'. Others have said that the cogito is not quite an inference, not quite an intuition, but a 'performance'. For a sense of what this debate is about, read Anthony Kenny, Descartes: A Study of his Philosophy (N.Y: Random House, 1968, ch. 3), and Jaako Hintikka, 'Cogito ergo sum: inference or performance?' in Willis Doney (ed.) Descartes: A Collection of Critical Essays (Doubleday 1967), 108-39. There you will also see some plausible candidate answers to the question: what kind of argument is the cogito, if it is an argument? Kenny pays special attention to the form of the argument as it appears in Meditation II.

The special status of 'I think' and 'I am'

Descartes says that there is something special about his belief that he is thinking, and his belief that he exists. What exactly is special about these thoughts? Descartes says that it is impossible to doubt these beliefs. So what is it about them that makes them immune to doubt? Descartes says in the passage above that 'the proposition I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind'. If these propositions are necessarily true, then that might be why they cannot be doubted. But are they 'necessarily true', as Descartes says? No, or not strictly. There are possible worlds in which Descartes does not exist. Perhaps in those possible worlds, his parents never met. If Descartes is taken to be the referent for 'I', then in those worlds the proposition 'I, Descartes, exist' is false. The proposition that 'I, Descartes, think' is also false, in those worlds. And something similar will apply no matter who the thinker is. These propositions are not necessarily true, in the usual sense in which philosophers speak of necessary truth. These propositions are contingent. But Descartes is surely right about their special status.

One suggestion is that these propositions have the special character of being incorrigible, and self-verifying. This suggestion has been made by Bernard Williams (Descartes: The Project of Pure Enquiry, ch. 3). It is assumed in his definitions that we are dealing with contingent propositions: propositions that are not true in all possible worlds. With that assumption, he proposes that a proposition P is incorrigible when it satisfies this description: if I believe that P, then P. Here are some candidate examples of propositions that satisfy this description. 'I am in pain.' This is, arguably, incorrigible, since if I really believe I am in pain, I am in pain. I can't be wrong about it. 'That looks red to me.' Here again, if I really believe something looks red to me, then it does look red to me. I am the expert about how things look to me. I might be wrong, of course, on how they really are. But (arguably) I can't be wrong about how they look to me. Now consider the propositions from Descartes' argument. 'I am thinking.' Suppose I believe that I am thinking. It follows that I am thinking. 'I exist'. Suppose I believe that I exist. It follows that I do exist. The propositions 'I think' and 'I exist' both seem to be incorrigible, in Williams' sense.

The propositions are also self-verifying. This is a closely related concept, which concerns assertion rather than belief. A proposition P is self-verifying when it satisfies this description: if I assert that P, then P. Here are some candidate examples of propositions that satisfy this description. 'I am speaking'. 'I can speak at least a few words of English'. 'I promise to come to the party'. If I assert (out loud!) that I am speaking, then I am speaking. If I assert that I can speak at least a few words of English, then I can speak at least a few words of English. If I say that I promise to come to the party, then I do promise to come to the party. The latter is an example of what Austin called a performative speech act. Some philosophers who see a similarity between this example and the propositions of the cogito have developed the 'performative' interpretation of Descartes' argument, mentioned above (see Kenny). Is there a similarity? Yes, in so far as all are examples of self-verifying propositions. If I assert 'I am thinking', then I am thinking. If I assert 'I exist', then I exist. Contrast these examples with self-refuting statements. 'I am absent.' 'I cannot speak any English'. 'I cannot think'. 'I do not exist'. (Can you imagine situations where these propositions might be used in a way that is not self-refuting?)

If this is correct, then there is indeed something special about the status of the propositions of Descartes' argument. Although they are strictly speaking contingent propositions, not necessary ones, they have the special features of being incorrigible and self-verifying. That is why they cannot be doubted.

However, there is a puzzle now. The conclusion Descartes wants to reach is 'I exist'. If this proposition on its own has the vital properties of being incorrigible and self-verifying, then why does Descartes bother with his premise, 'I think', and trouble to present the argument as 'I think, therefore I am'? The answer is not obvious, but here are two suggestions.

The first is that there is one formulation of the argument presented in the Meditations which can be interpreted in just this way. Descartes says, 'the proposition...I exist, is necessarily true whenever it is...conceived in my mind.' This could be interpreted exactly in line with Williams' suggestion: 'if the proposition 'I exist' is believed by me (conceived in my mind), then it is true'. In Williams' terminology: the proposition 'I exist' is incorrigible. On this reading, the conclusion 'I exist' is inferred from a thought about one's existence. This still leaves all the other formulations of the argument, however, in which existence seems to be inferred from thoughts about something other than one's existence (25). 'If I convinced myself of something, then I certainly existed.' If there is a deceiver who is deceiving me, 'in that case too I undoubtedly exist'. If I 'thought anything at all, then I certainly existed' (French version). In all these cases the premise that is supposed to yield a conclusion about existence is not a thought about one's existence, but rather a thought about e.g. a deceiver.

The second suggestion is that there is indeed a special reason for the premise of the argument being 'cogito', 'I think'. The proposition 'I think' has a special feature that is lacking in the proposition 'I exist'. The proposition 'I think' is evident (to use Williams' label). A proposition P is evident to me if it satisfies the following description: if P, then I believe that P. Compare this definition to the definition for incorrigibility above. You can see that being evident is roughly the converse of being incorrigible. Incorrigibility says, if you believe it, it's true. Evidence says, if it's true, then you believe it. If something is incorrigible to you, then you are an expert about it, in one way. If you believe it, it's true. If something is evident to you, then you are an expert about it in a different way. If it's true, then you believe it. It doesn't escape your attention.

It may be that Descartes thinks that all propositions about the mind are incorrigible and evident. Incorrigibility says: when I believe something about my mind, I get it right. If I believe some proposition about my mind, that proposition is true. That, on its own, is compatible with there being all kinds of dark corners and alleys of the mind about which I know nothing. But then Evidence adds: I know all there is to know. If some proposition about my mind is true, then I believe it. The poet Gerard Manley Hopkins said, 'O the mind, mind has mountains; cliffs of fall / Frightful, sheer, no-man-fathomed.' Descartes would have disagreed; he seems to think there are no unfathomable depths to the mind. There are no hidden corners or dark alleys. The mind is transparent to itself. I can know about all the operations of my mind.

While the propositions 'I think' and 'I exist' are both incorrigible, and both self-verifying, the proposition 'I think' is evident, in a way that the proposition 'I exist' is not. If I think, then I believe that I think. Is it true that if I exist, I believe that I exist? No, it seems. While I believe that I think, when I am thinking, I do not always believe that I exist, when I am existing. Perhaps I can continue to exist in a dreamless, thoughtless sleep, and surely that is what common sense supposes. In that case I exist, but do not believe I exist, since I do not believe anything. While 'I exist' is incorrigible, it is not, on the face of it, evident. So Descartes has a reason for choosing to begin his argument with the premise 'I think'.

Essence and existence

There is another reason for beginning with the premise 'I think' in the famous argument of the cogito, which brings us to the question not only about the existence of the 'I', but about the nature of that 'I'. Descartes wants to argue that thinking and existence are very closely connected, in the case of a self that thinks. After addressing the question of his existence, the thinker of the meditation will address the question of his own essence or nature. He will argue in the end, 'I am essentially a thing that thinks'. An essential property of a thing is a property which that thing is bound to have: a thing cannot lose a property essential to it without ceasing to exist. Perhaps an essential property of a cat is that it is an animal; perhaps an essential property of a yeti, too, is that it is an animal. Notice, from the last example, that we can talk about the essential properties of things without being committed to the existence of the things. Nevertheless, truths about essence have implications for existence: if a cat exists, it must be an animal; if a yeti exists, it too must be an animal. If it were not an animal, it would not be a cat; if it were not an animal, it would not be a yeti.

If Descartes' argument that the 'I' of the Meditations is essentially a thinking thing is successful, then the implication is similar: if I exist, I must be thinking. If Descartes' argument about his essence is correct, he will be able to argue in either direction. I think, therefore I am (cogito ergo sum). And, I am, therefore I think. (I am essentially a thinking thing.) This symmetry will be central to Descartes' vision of what it is to be an 'I', a soul, or self, or mind: I am if and only if I think. Notice that if this thesis about essence is correct, it will have the consequence after all that 'I exist' is not only incorrigible, as described above, but also evident: if I exist, then I will think, and therefore (by the cogito) I will believe that I exist. However, this thesis about the essence of the self is yet to be argued for.

You will notice that throughout the Meditations, Descartes carefully distinguishes the question of the existence of something, from the question of the essence or nature of that thing. Both kinds of questions concern metaphysics: What exists? What are things like? Sometimes we might know that something exists, without knowing what it is like. You come home in the dark to a house that you expect to find empty, and you hear an ominous rustling inside. Something is there, but you don't know what it's like. Is it a cat? A burglar? A friend? In such a case you might say, in Descartes' terms, that you know of the existence of something, but you don't yet know its essence, its nature. Sometimes it might be the reverse. You know what Santa Claus is like, you know what his nature is: an old man, white-bearded, red-suited, with a generous disposition and a hearty laugh. (Perhaps not all of these properties belong to his essence. Could there be a young Santa? A beardless one? A female one?) You know, more or less, what Santa is like: but does he exist? In this case you know what his nature is before you settle the question of whether he exists. The sceptical arguments of the First Meditation have, in general, left the meditator in ignorance about the existence of things. The meditator knows what trees, fires and dressing gowns would be like: but he is not sure whether there are any. He knows what his body would be like, if it existed (something with hands, extended in space, etc.), but he is not sure whether it does exist.

This pattern is typical of the Meditations. The meditator typically begins by answering some question about essence, and then raises the question about its existence: he will begin by describing the essence of some kind of thing, whether bodies, or shapes, or God, and thereafter raise the question of whether that thing in fact exists. Descartes assumes that the essence of a thing can generally be known before one knows whether the thing exists, because the essential properties of a thing are implied by the idea or concept of that thing. For example, the idea of a triangle implies the essential properties of a triangle: a closed three-sided figure. That tells you something about the concept of a triangle. And it tells you something about the world: if you come across an existing triangle, it will have three sides. The idea or concept of a yeti implies that being an animal is an essential property of a yet. That tells you something about the concept of a yeti. And it tells you something about the world: if you come across an existing yeti, it will be an animal. You can have an idea or concept of a thing prior to knowing whether the thing exists: so in many cases you can know the essence of something before knowing whether it exists.

The grand exception to this general pattern in the Meditations is, of course, knowledge of oneself. In the argument of the cogito, the thinker concludes, 'I exist'. It is only after establishing this conclusion about his existence that he raises the question: what am I? What is my nature? What is my essence? Immediately after the conclusion of the cogito, Descartes says: 'I do not yet have a sufficient understanding of what this 'I' is, that necessarily exists' (25). I know that I exist, but I do not yet know what I am. I know of my existence, but I do not yet know of my essence.

The rest of the Second Meditation is devoted to arguing that the essence of the self, or 'I' (whose existence has been proved in the cogito) is to think. Notice that the subtitle of this Meditation is basically devoted to this issue about the nature of the self or mind: 'The nature of the human mind, and how it is better known than the body'. Notice the mention of 'body' in the title. The meditator will address an important question about the essence of matter, or body, whose existence is still entirely in doubt. But the purpose there too will be to establish a thesis about the mind: that it is better known than the body.

Essence of the self, or mind

The argument of the cogito concludes 'I exist': but who or what is it that exists? Not a human body. Not a soul in the traditional Aristotelian sense. Aristotle had identified the soul with certain capacities that living things possess: capacities of nutrition, reproduction, locomotion, perception, and thought. On the Aristotelian account, all living things have souls: plants have the first two capacities, non-human animals have the first four, and human beings have all five. Descartes considers four of these capacities (coyly omitting reproduction!), and argues that none but the last capacity, thought, is essential to the nature of the soul.

What about the attributes I assigned to the soul? Nutrition or movement? Since now I do not have a body, these are mere fabrications. Sense-perception? This surely does not occur without a body, and besides, when asleep I have appeared to perceive through the senses many things which I afterwards realized I did not perceive through the senses at all. Thinking? At last I have discovered it - thought; this alone is inseparable from me. I am, I exist - that is certain. But for how long? For as long as I am thinking. For it could be that were I totally to cease from thinking, I should totally cease to exist (27)

He somewhat overstates his case here, to emphasise the point: the meditator is not denying the proposition 'I have a body', but rather refusing to assent to it, since the arguments of the First Meditation show that it is dubitable. I can doubt that I have a body: so I can doubt that I have any of the bodily capacities described on the Aristotelian picture, whether of nutrition, locomotion, (reproduction), or perception, in so far as that involves bodily sense organs. (Notice that in so far as perception has a mental aspect, Descartes will treat it as a mode of thinking, 28) All capacities other than thought are vulnerable to the sceptical arguments of the First Meditation. Descartes concludes that his essence is to think. Sum res cogitans: 'I am a thing that thinks' (28). Notice that Descartes appears to believe he has established not only 'I think'; not only 'I am a thinking thing'; not only 'thought is a property essential to me'; but the strong conclusion that 'thought is the only property essential to me'. Thomas Hobbes was to complain in the Third Objections that Descartes has not ruled out the possibility that the 'thing that thinks' is also a corporeal or material thing (for example a human body, or brain):

it may be that the thing that thinks is the subject to which mind, reason or intellect belong; and this subject...may be something corporeal (173).

Have a look at Descartes' reply in your edition of the Meditations. How fair and plausible is it? This argument about the essential nature of the mind, and its distinctness from the body, will be a major concern of Meditation VI.

Essence of body

We have knowledge of the self: but surely, so the naive view runs, our knowledge of bodies, through the senses, is still more distinct? Descartes considers our knowledge of a particular body: a piece of wax. Or rather, since he has not yet countered the sceptical arguments of Meditation I, he is considering the concept of a particular piece of matter, without committing himself to its existence. He is conducting a kind of thought experiment. Suppose that I were to have knowledge about a material thing. What would its essence be? And how would I know it? The wax is white, scented, hard, cold: these seem to be properties that enable me to understand it distinctly. All those properties disappear when it is placed by the fire: but the thing still continues to exist. 'What was it in the wax that I understood with such distinctness?' Not the fragrance, hardness, coldness, but merely something 'extended, flexible and changeable' (31). This is a variant of a 'think away' argument, to discover the essential properties of something. (Think away Santa's white beard. Could he still be Santa? If so, then the white beard is not essential to him.) Unfortunately it is not quite clear what essence Descartes is trying to discover: it is not quite clear whether he is asking a question about the essential properties of wax in general, or a particular lump of wax, or of matter in generalquestions which would all have different answers (what might they be?). Here it will be assumed that Descartes intends to discover the essence of matter in general. (For a particularly helpful discussion of the 'wax passage' see John Cottingham, Descartes (Blackwell, 1986) 80-81.)

Descartes reaches a conclusion about the essence of matter. He concludes that the concept of 'body' is the concept of something essentially extended, with shape and size, capacity for change of shape and size, and that is all. This anticipates the mind/body dualism, and the doctrine of primary and secondary qualities, developed more fully in the later Meditations.

One question about matter concerns its essence: what would matter be like, if it existed? Another concerns our knowledge: how would we have knowledge of matter, if it existed? Descartes reaches the apparently radical conclusion that bodies, or rather the essential properties of bodies, are known not by mere sense perception, or imagination, but the intellect: perception always involves judgment. This applies to the sensory perception of all material bodies. It applies to the sensory perception I would have of the wax, if it were to exist. And it also applies to perception of the most mundane things: the people I seem to see outside the window (32). Even if perception were veridical (which the First Meditation gives us reason to suspect), perception would not yield acquaintance with the people themselves, obscured by hats and coats. To judge that they are men is to go beyond perception would tell us: it is to use one's intellect.

Descartes concludes this Meditation with some more morals about the self. Knowledge of the self, or mind, is more distinct and certain than knowledge of body. The knowledge of the self given by the cogito argument is prior to knowledge of body, and immune to sceptical worries about body. Moreover, every judgment about body helps me to know myself better. 'Every consideration whatsoever which contributes to my perception of ...body, cannot but establish more effectively the nature of my own mind' (33). This follows from the thesis about the transparency of the mind to itself: in Williams' terms, the thesis about the evidence of propositions about the mind. If I judge that there are men below in coats and hats, then I know that I judge that there are men below in coats and hats, so I know something not only about them, but about myself. The more I learn about anything else, the more I learn about me. Descartes's conclusion was objected to by the philosopher Gassendi, and his objection, and the reply Descartes gave, are to be found at 276-7, and 360. Gassendi's point seems to have some plausibility; see what you think.

Conclusion

The method of doubt in the First Meditation appeared to threaten all knowledge, but in the Second Meditation the thinker finds something that cannot be doubted. Having tipped out the barrel, the thinker finds one apple that is sound. Having demolished the building, he has discovered a piece of timber that is firm, and that can (he hopes) form the foundation for rebuilding the edifice. Moreover, if his arguments have succeeded, he has discovered the essence of mind, which is to think; and the essence of matter, which is to be extended. And he has discovered that, contrary to common sense, the mind is more knowable than the material world.

Some questions to consider about Meditation II

(1) One of Descartes' critics, Gassendi, complained that the thinker could have inferred his existence from any of his activities: that the premise about thought was not necessary. An example, given in Descartes reply, is 'I am walking, therefore I exist'. Putting yourself in Descartes' shoes, can you imagine how Descartes will reply to this objection? Write down your reply on Descartes' behalf. Now look at how Descartes in fact replies (259, 352).

(2) How plausible is it that propositions concerning your own mental states are incorrigible to you? Is it possible to make mistakes about our own beliefs and desires? I might falsely believe that I like the taste of beer, when really I hate it, but pretend to everyone including myself that I like it, so I can be one of the crowd at the pub. Is that a possibility? Many people, and many philosophers, think that self-deception is possible. For example, if someone 'turns a blind eye' to the lipstick on her husband's collar, she somehow pretends to herself that he is faithful. In such a case she will have beliefs about her mental states that are not incorrigible: she may believe that she believes he is faithful; but in fact she believes he might not be. Let P be the proposition 'I believe he is faithful'. In this example, she believes that P; but in fact not-P is the case. She is wrong about what she believes: P is not incorrigible.

(3) How plausible is it that propositions concerning your own mental states are evident to you? If self-deception is possible, then that is relevant to the evidence issue too. There may be truths about one's mental life about which one is not aware. The woman in the previous example may believe 'deep down' that her husband is having an affair: but that belief is not transparent to her. She does not believe that she believes it. Let S be the proposition 'I believe he is having an affair'. In this example, S is the case; but she does not believe that S. She has a belief of which she is not aware. S is not evident. More generally, if there are unconscious mental processes, as many (most famously Freud) have argued, does that undermine Descartes' view?

(4) How plausible is Williams' suggestion about evidence, as an interpretation of Descartes? So far we have been speaking as though Williams is correct, but his interpretation may be disputed. Descartes claims that we are conscious of our thoughts. He does seem to think that facts about our mental life are in some way transparent to us. That seems to entail that, for every thought I have, I believe I am having that thought. And that I in turn believe I am having that belief, and so on, indng of an elephant. The same applies to the next proposition. If I believe I am thinking about an elephant, I believe that I believe it, and so forth, indefinitely. Yet Descartes appears to explictly reject this understanding in the Sixth and Seventh Replies. How? Have a look at 422, 560, in the Objections and Replies, and see if you can make up your own mind whether Williams is right.

THIRD MEDITATION
The existence of God

So far Descartes' sceptical arguments have threatened all knowledge but the knowledge of self provided in the cogito. But instead of turning now to the question of how knowledge of material things may be possible, the thinker turns in the Third Meditation to a question about God. 'I must examine whether there is a God, and, if there is, whether he can be a deceiver. For if I do not know this, it seems that I can never be quite certain about anything else' (36). He believes he must prove the existence of 'the true God, in whom all the treasures of wisdom and the sciences lie hidden', as he puts it later in the Meditations (53). Knowledge of God's existence is seen as the foundation of, and more certain than, all knowledge other than immediate self-knowledge. (Where then does God belong, in Descartes' metaphor of the tree of knowledge, mentioned in the discussion of Meditation I?) The importance of this Meditation is two-fold: firstly in its methodological proposal about clear and distinct ideas, developed in more detail later; and secondly in its conclusion that God exists.

Clear and distinct ideas

Descartes reflects on the arguments of the Second Meditation, and asks: what is it about the argument which made me so certain about it? He says that it is the clarity and distinctness of his perception of it.

I am certain that I am a thinking thing....In this first item of knowledge there is simply a clear and distinct perception of what I am asserting; this would not be enough to make me certain of the truth of the matter if it could ever turn out that something which I perceived with such clarity and distinctness was false. So I now seem to be able to lay it down as a general rule that whatever I perceive very clearly and distinctly is true. (35)

If clarity and distinctness are a sure sign of truth, then we have the beginnings of a path out of the sceptical morasse. Not only do I know of my own existence, and essential nature. Guided by the principle of clear and distinct ideas, I can keep to the path of truth by assenting only to those ideas that are clear and distinct. Strictly speaking it is judgments, rather than ideas, that can be true or false (37). If I were to consider ideas merely as what they are, namely modes of my thought, 'they could scarcely give me any material for error'. However, my chief error consists in 'judging that the ideas which are in me resemble, or conform to, things located outside me'. My main source of error is a hasty judgement that some idea corresponds to, resembles, some reality outside me. Then I make judgements that are false. The principle about clear and distinct ideas can help me to avoid these errors. Here we have a hint of things to come: Descartes' theory of error and judgment, which is the proper topic of Meditation IV.

God

Two independent arguments for the existence of God are given in the Meditations, one in Meditation III, the other in Meditation V. The latter will be addressed in due course. The argument in the Third Meditation is interesting, but it makes use of certain Scholastic metaphysical concepts and principles. This presents the reader with two kinds of problem. (1) The concepts and principles are a little unfamiliar and archaic. However, some are interesting and important, and with a little effort can easily be grasped by a modern reader, especially with the help of explanations of the kind offered by Cottingham. (2) It is not obvious that Descartes is entitled to these metaphysical assumptions. Isn't he supposed to be doubting everything but the indubitable? Some readers may find the principles used by Descartes rather easy to doubt. The argument in the Third Meditation is known as the 'Trademark Argument', since the thinker's idea of God is described as if it were a trademark that the creator has left in his creature:

it is no surprise that God, in creating me, should have placed this idea in me to be, as it were, the mark of the craftsman stamped on his work (51).

The Trademark Argument for God's existence

The thinking begins by reflecting on the furniture of the mind, whose existence he has proved. I have many ideas, he says, some of which seem to be innate, some adventitious, some invented by me (38). Ideas can be considered in terms of their 'formal reality' (as mental states), or their 'objective reality' (as representational content) (40). Here is an analogy: a newspaper photograph of a yeti may be considered in terms of its 'formal reality' (a real ink-patterned piece of paper), or its 'objective reality' (a representation of a yeti). The question may then be raised: does the yeti depicted in the photograph really exist? In Descartes' terminology, that is the question: does the yeti have 'formal reality', in addition to the 'objective reality' it has as an 'object' of a photograph? Descartes' distinction is still important, although the labels philosophers use nowadays are not the same. Philosophers now might say: does the yeti exist? Or is the yeti a merely intentional object?

[Digression: a warning about terminology] Nowadays the usage of the word 'objective' is almost the opposite of Descartes' usage: to say that something exists 'objectively' in the modern sense, is (more or less) to say that it exists 'formally', in Descartes' sense. If, nowadays, we were to say, 'the yeti exists objectively', we would mean simply that it exists. We would mean that it exists, as a real animal, and not as the merely intentional object of people's hallucinations and nightmares and photographic forgeries. This terminological change can cause confusion: and in your own work, you should make it clear whether you follow Descartes' usage, or the modern one, if you ever use these words. [End of Digression]

The thinker applies this distinction to the case of God. Among my various ideas is an idea of God (43), which represents God as being eternal, infinite, omnipotent. God thus has 'objective' reality, which means that he exists as the 'object' of my idea. The thinker raises a question: does God have formal reality in addition to the objective reality he has as 'object' of my idea? In other words, does the God of which I have an idea exist independently of my idea? The idea or concept of God describes, so to speak, the essence of God: it is the idea of

a substance that is infinite, eternal, immutable, independent, supremely intelligent, supremely powerful, and which created both myself and everything else (if anything else there be) that exists (45).

We can know the essence of God, just as we could know the essence of material things (the wax), just by reflecting on our concepts. We can know the essence of God: but does God exist? We know that God has 'objective' reality, as the object of my concept or idea: but does God have formal reality as well?
Yes, according to the Trademark argument. God exists. God has formal reality, in addition to merely 'objective' reality. That will be the conclusion. What is the argument? The thinker focuses on a question about causality. What is the cause of this idea I have of God? According to the thinker, it is self-evident that, as a general principle, 'there must be at least as much reality in the efficient and total cause as in the effect of that cause' (40). This is described by Cottingham as the Causal Adequacy Principle. If we find a clock, the cause of that clock must be at least as complex as the clock. The same is true if we find a mere blueprint of a clock. The cause must have as much reality as the clock represented by the blueprint. Now apply the Causal Adequacy Principle to the idea of God: the idea of God has an infinitely high degree of objective reality. Its cause cannot be myself: for I am imperfect, finite, deceived. The only possible cause is God himself. God, 'in creating me [has] placed this idea in me to be...the mark of the craftsman stamped on his work' (51).

The thinker concludes that God exists. Moreover, since the concept of God is the concept of an infinitely perfect being, the thinker reaches a conclusion which will prove to be vital for the progress of the next Meditations: God exists, and is not a deceiver.

By 'God' I mean...the possessor of all the perfections...who is subject to no defects whatsoever. It is clear enough from this that he cannot be a deceiver, since it is manifest by the natural light that all fraud and deception depend on some defect (52).

For a more detailed exposition of the Trademark Argument for God's existence, read Cottingham, Descartes (Blackwell, 1986), ch. 3.

Some questions to consider about Meditation III

(1) How well does Descartes support his apparent premise that every thinker has an idea of God, innate within us? Notice that this was denied even at the time of the publication of the Meditations, by Hobbes, who flatly contradicted Descartes: 'there is no idea of God in us', he said. See the Third Objections (180). A similar point is made in the Second Objections, 124. This has implications for a broader issue that will be discussed later in the course: the question of whether there are in fact any innate ideas, whether of God or other things.

(2) How well does the argument fare by the criterion of clarity and distinctness? Another critic said, more piously than Hobbes, that since the idea of God is the idea of an infinite being, the finite human intellect is not capable of conceiving it (286). We can spell out the objection further. If we are not capable of conceiving it, then we are not capable of conceiving it clearly and distinctly. So by Descartes' criterion of clarity and distinctness, we should refrain from making any judgements about God. (Descartes' reply is at 365.)

(3) How plausible is Descartes' use of the concept of 'objective reality'? One of Descartes' critics, Caterus, complained that this was not a kind of reality at all. Far from having an infinite degree of reality, the idea of Godconsidered as something distinct from a property of one's mindhas no reality at all. 'Why should I look for the cause of something which is not actual, and which is simply an empty label, a non-entity?' (First Objections, 92)

(4) How plausible is the Causal Adequacy Principle? Mersenne objected to it as follows:

You say...that an an effect cannot possess any degree of reality or perfection that was not previously present in the cause. But we see that flies and other animals, and also plants, are produced from sun and rain and earth, which lack life (123).

Mersenne here produces some candidate counter-examples to the Causal Adequacy Principle: the possibility of spontaneously generated animals and plants. It was believed at the time, and until much later, that some organisms (e.g. flies) could be spontaneously generated (e.g. from mud, and rotting material). Descartes replies that animals and plants are not really more perfect than sun and rain and earth; but that if they were, those inanimate causes would not be sufficient to produce them (134). You might be tempted to agree with Descartes, against Mersenne. You might be tempted to reply that in addition to these raw materials of sun and rain and earth, something more is indeed required. Plant seeds, and insect eggs, are required to produce these 'more perfect' beings: showing that in these cases the causes (parent organisms) do indeed have as much reality as the effects (their offspring). It is true that Mersenne's assumption about the possibility of spontaneous generation was refuted much later (by Louis Pasteur), but it would be a mistake to conclude that Descartes is right. There is a sense in which most modern readers still agree with Mersenne. According to the theory of evolution, less 'perfect' beings ('sun and rain and earth') can indeed be the causes, given enough time, of more 'perfect' beings (plants, animals, and ourselves). Mersenne's counter-examples are good ones, interpreted the right way. In so far as science today endorses the theory of evolution, it agrees with Mersenne's objection, and rejects the Causal Adequacy Principle which seemed so evident to Descartes.

(5) How plausible is Descartes' conclusion that the idea of God requires a cause that can only be God himself? This question rests in part on the plausibility of the Principle discussed above, but it also raises distinct issues about the origin of concepts. The idea of God is the idea of an infinite being. Mersenne asks: why couldn't this concept of God be constructed by the thinker himself? Descartes has acknowledged that on reflecting on his own nature, he realises that he is a finite being. Couldn't the concept of an infinite being be constructed by extending the 'degrees' of perfection indefinitely upward, starting from one's own case? Mersenne suggests, by analogy, that one could construct the concept of something that is infinitely hot, once one has the concept of something that is hot to a certain particular degree. Whether or not the example is a good one, the point seems clear: God is not the only possible source for the idea of an infinite being (123-124). In fairness, you should read Descartes' response to Mersenne (134-6).

[The end of Study Guide to Descartes' Meditations: Part II]
[Study Guide to Descartes' Meditations: Part I]
[Study Guide to Descartes' Meditations: Part III]