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 commentary 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.
This 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).
The Third Meditation, if successful, has established that God exists, and that he is not a deceiver. The next Meditations try to build a bridge, a 'way forward' to the knowledge of other things. But the conclusion of the Third Meditation also poses a hard question for Descartes. If God is not a deceiver, then he cannot have created me in such a way that I am inevitably deceived: but then how is it that I ever make mistakes? This is the problem of error, and Descartes' response to this problem, and his account of error, is the most interesting and important aspect of the next Meditation.
FOURTH MEDITATION
Truth and falsity
Descartes will want to argue as follows. God is perfect, and I am God's creature, so I have an intellect which, when correctly used, is reliable (54). What this means remains to be considered. But we can see already that it provokes a second hard question. If I can know that my intellect is reliable only after establishing God's existence, then how can I establish God's existence in the first place? I need to trust my intellect to prove God's existence, yet without knowledge of God's existence I am not entitled to trust my intellect. This is the problem of the 'Cartesian Circle', which will be considered more closely in the discussion of Meditation V.
The problem of error and Descartes' solution to it
If God exists, and created me, and is not a deceiver, then how is it that I ever make mistakes? No-one could deny that we sometimes make mistakes, and Descartes never denies it. The First Meditation, recall, was premised on the fact that we sometimes make mistakes, and this fact was used to generate the global sceptical challenge. We are sometimes deceived (through perception, or dreaming): what reason to we have for thinking we are not always deceived? Even if Descartes, in the end, replies to the sceptical challenge, he is still left with the fact that we sometimes make mistakes. The problem, as Descartes presents is, is similar to the traditional problem of evil: if God the Creator exists, and is good, then why is his creation partly evil? The traditional answer to this question was that God created us with a free will, and that evil is a result of the misuse of that freedom.
Descartes' first response to the problem is one of creaturely humility: God's
purposes are impenetrable to us, and if we were less limited in outlook, we
might see that our faults 'have a place in the universal scheme of things' (56).
Descartes second, and most important, response is in his theory of judgement.
Errors are mistaken judgements. When we enquire closely into the nature of
judgement, we find that it involves the two faculties of the intellect
and the will (56-58). Both are faculties of the self or soul whose
existence is proved in the Second Meditation; and the activities of perceiving
ideas, and the activities of willing, both count broadly as activities of
thinking, in Descartes' sense.
The activity of the intellect is limited. '[All] the intellect does is to
enable me to perceive the ideas which are subjects for possible judgements; and
when regarded strictly in this light, it turns out to contain no error'. The
intellect does not, on its own, declare certain propositions to be true or
false. It simply puts forward and considers ideas or propositions without giving
a verdict on those ideas or propositions. The intellect alone does not make
judgements. And error is false judgement. Judgements are made when the ideas put
forward by the intellect are affirmed or denied by an act of the will.
Affirmation and denial are mental acts, performed not by the intellect but by
the will. Error arises when the will affirms ideas that are not clear and
distinct, and the will thereby makes a false judgement. On this picture, the
intellect is like a rather disorganised and un-opinionated lawyer, who presents
evidence in a somewhat indiscriminate way: some of the ideas presented are clear
and distinct; some of the ideas are unclear and indistinct; there are great gaps
in the evidence due to the ignorance of the intellect; and the intellect does
not, on its own, bring a verdict on any of the ideas it surveys or proposes. The
will is like a judge who considers the evidence put forward so indiscriminately
by the intellect, and brings a verdict on it. For example, the intellect may
non-commitally propose the idea that a triangle has three sides. The will gives
its verdict. 'Yes, that idea is a good one. It is clear and distinct. I shall
affirm it.' In this way, judgements involve the co-operative activity of
intellect and will, but it is the will that (so to speak) makes the decisions.
(There are problems with this way of speaking: to decide is to use one's will,
but there is something odd about saying that the will decides. We will not
address these problems though.)
This is possible because God made me with a finite intellect, and an infinite will. The second Meditation had concluded that the self is in some way finite: and in this Meditation we learn that it is finite with respect to the intellect. The intellect has limits: limits to its scope (it does not have ideas about everything); and limits to its acuity (not all of its ideas are clear and distinct). The will, on the other hand, is infinite:
The conjunction of finite intellect with infinite will provides the freedom to err. The intellect does not provide me with ideas that are all clear and distinct, and the will is free to affirm or deny any of them. Error can be avoided if I refrain from affirming ideas that are not clear and distinct. Error, like sin, is a result of man's abuse of his free will. Human error is thus compatible with God's not being a deceiver, just as human sin is compatible with the goodness of God.
Belief and the will
According to Descartes, belief is an idea put forward by the intellect and affirmed by the will. What is striking about this picture is that belief involves the the will in just the same way that practical action involves the will. I may choose to act in a certain way: I may choose to donate to Community Aid Abroad; I may choose to steal a lollipop from a baby. I may choose to act rightly; or I may choose to act wrongly. Similarly, I may choose to believe a certain way: I may choose to believe that 2 plus 3 make 5; I may choose to believe that matter is better known than mind. I may choose to believe rightly; or I may choose to believe wrongly. Belief is here treated as a kind of action. And truth is here treated as a kind of goodness. One of the central questions about Descartes' account is whether this analogy between belief and action holds. Many philosophers deny that belief and action are alike, for reasons having to do with 'direction of fit'. Bernard Williams, for example, says that we cannot simply believe at will in the way we can act at will.
Descartes says we can choose to believe. How? Surely Descartes' own
commitment to finding indubitable beliefs is a commitment to finding
beliefs that I cannot resist. But if I cannot resist these beliefs, in what
sense do I 'choose' to affirm them? Examples of beliefs which Descartes has so
far argued to be indubitable are the following. 'I think'. 'I exist'. 'The
essence of matter is to be extended.' 'I am essentially a thinking thing'. 'God
exists.' 'God is not a deceiver.' Whether we find all these propositions to be
equally irresistable is not the point. Descartes says they cannot be doubted.
But if they cannot be doubted, how do I 'choose' to affirm them? Doesn't choice
imply that I could have done otherwise?
Perhaps we could say in Descartes' favour that there are indeed circumstances
in which a person can choose to believe. In his Replies to the Fifth Objections,
Descartes says that sometimes you can believe something just because you
want to believe it (377). You can sometimes believe something for reasons
that are independent of the truth of the belief, or the evidence you have for
it, or the clarity with which you understand it. You can believe something for
pragmatic reasons. You believe something, because it is easy, or comfortable, or
pleasurable to believe it. Descartes gives two examples. One is a belief that
the mind is an extended, or material, thing, a belief which you persist in
because it is familiar and comfortable, even though you have no clear
understanding of it: 'you simply want to believe it, because you have believed
it before, and do not want to change your view'. Another is a belief that a
poisoned but pleasant-smelling apple is nutritious: 'you understand that its
smell, colour and so on, are pleasant, but this does not mean that you
understand that this particular apple will be beneficial to eat; you judge that
it will because you want to believe it''. Here there are certain advantages of
comfort and pleasure to having these (false) beliefs. You believe them not
because they are true, or clearly understood: you believe them because you want
to. Descartes gives these examples to illustrate that one can indeed will to
believe, that the scope of the will is greater than that of the intellect, and
that this can lead to error.
Other examples of believing something because you want to, are given by cases
of self-deception. The woman who wants to believe that her husband is faithful,
can perhaps choose to believe it: she believes that he is faithful because she
wants to, not because she has evidence that he is. It is useful to believe it,
whether or not it is true. Or perhaps (as imagined earlier) she can at least
choose to believe that she believes it, even if deep down she doesn't. How we
are to understand cases of self-deception though is a difficult question, about
which philosophers are still not agreed.
A different and famous example of deciding to believe is Pascal's Wager,
named after the French philosopher who described it and (perhaps) acted by it.
If I think there is even a chance that there is a God who condemns atheists to
hell, I can prudently choose to believe in God. I might reason like this. If
there is a God, and I don't believe in him, I will go to hell. If there is a God
and I do believe in him, I won't go to hell. If there isn't a God, and I don't
believe in him, I won't go to hell. If there isn't a God and I do believe in
him, I won't go to hell either. The worst case scenario is the first. Not
believing in God is riskier than believing in God. If I believe in God, I'm fine
no matter what. So I should believe in God. Notice that this argument says:
believe 'God exists', because that would be useful. It does not say: believe
'God exists' because that would be true, or there is good evidence for thinking
it true. The argument offers a pragmatic reason, not a theoretical one. Now, I
can't just believe it at the drop of a hat, faced with a pragmatic reason of
this kind. I must take things more slowly. I gradually adopt the practices of
people who do believe in God, first as a kind of pretence. I gradually find that
I have achieved the necessary belief, and thereby saved myself from the risk of
hell. (Is self-deception involved in Pascal's Wager? Is the wagerer like the
woman in the last example, believing something because it is useful or
comfortable, not because it is true?)
Another kind of case is presented by self-fulfilling beliefs. Suppose I am
standing by the bank of a stream, and I want to leap across. The gap looks too
big to jump. But perhaps I can do it. I don't have any evidence either way. It
looks just on the limit. 'You can do it!' I tell myself. I make myself believe I
can do it. I decide to believe I can do it. And I can do it! Deciding to
believe gives me the confidence to make the leap. My belief makes itself true.
(This example is from William James, 'The Will to Believe', in The Will to
Believe and Other Essays in Popular Philosophy, Longman's, Green and Co.
1891.) Of course there are limits here on what you could decide to believe, in
cases like these. One metre, yes, perhaps; five metres, no.
It seems that you cannot believe something in the teeth of overwhelming evidence against it. The clearest cases where you seem to be able to believe something because you want to are cases where the evidence does not compel you either way. When belief is not compelled by evidence or argument, there is sometimes scope for choice. We can sometimes believe what we want to believe, with sometimes good, sometimes sorry consequences. For a sad but not unusual example of the latter, take this report about the burning of a town in Kashmir, in which 1500 houses and a sacred shrine were destroyed.
What implications would it have for for Descartes' theory, if the cases where
we are able to choose to believe are cases where evidence or argument does not
compel us firmly in one direction or the other? The clearest cases seem to
involve a certain kind of irrationality: believing something in teeth of some
evidence against it (the self-deceived wife), or believing something in the
absence of evidence for it. The clearest cases of willed beliefs are examples of
bad beliefs: beliefs that are bad by Descartes' own lights. Descartes has argued
that we should believe only what we have compelling reason to believe: we should
believe only what is perceived by the intellect to be clear and distinct. We
should resist believing anything that is not 'clear and distinct'. So the freely
chosen beliefs of these examples are not good beliefs.
The implications for Descartes' theory are mixed. Descartes says that his
theory about belief and the will can perform two tasks: it can account for
error, and it can account for the nature of judgement in general. The first
claim is plausible, in part. When we believe something for pragmatic reasons,
because we want to believe it, because it is comfortable or pleasant or useful
to believe it, we can indeed be led into error, just as Descartes says. Error
can arise from deciding to believe. Error can arise from the misuse of the will.
But it is not likely that all errors arise this way. (Can you think of some that
do not?) And as for the second claim, it is not plausible that Descartes' theory
can account for the nature of judgement in general.
Belief, in general, does not seem to be under the control of the will. It
would be nice to believe that the sun is shining, that there are no nuclear
weapons, that I have a million dollars in the bank. It would be nice if I could
just decide to believe it. It can be nice to have false beliefs. Sometimes I can
manage to believe things, just because it would be nice to believe them.
Usually, though, I can't. Bad beliefs cannot just be chosen. On Descartes'
account of judgement, it is hard to see why not. Good beliefs are not just
chosen either. Beliefs that are irresistible, indubitable, are the best beliefs
(on Descartes' criteria), and at the same time the least open to choice. Do I
decide to believe that I exist? Do I decide to believe I am thinking? Do I
decide to believe that 2 plus 3 make 5? I cannot help believing them. The best
beliefs are the least subject to the will.
Descartes does address this issue. He says,
Recall that Descartes says the will is involved both in action and belief. Wrong action (sin) is like wrong belief (error). I (and not God) am responsible for both, and both involve a misuse of the will. Descartes wants to draw a very close analogy between believing and acting, and it emerges clearly in the passage just quoted. He is talking about freedom in general, as it applies to both action and belief. He says, when I am very strongly inclined in one direction to believe or to act, because I clearly understand that reasons of truth (in the case of belief) and goodness (in the case of action) point that way, I am free. Notice the assimilation: 'reasons of truth and goodness'. I perceive that some action is good, and I decide to do it. I perceive that some proposition is true, so I decide to believe it. This is a plausible description of action. Because Descartes thinks belief is very much like action, he sees it as a plausible description of belief as well.
Some questions to consider about Meditation IV
(1) Can you find a way of making sense of Descartes' claim that the will is infinite? Notice that Gassendi criticised Descartes on just this point in the Fifth Objections (313-315), and Descartes attempted to give a good reply (377).
(2) Can you think of any cases where a person cannot help believing something false? If so, this would be an apparent counter-example to Descartes' claim that error is always something I can in principle avoid. Would that show that error is not entirely the responsibility of the individual misuse of the willthat God is responsible for it?
(3) Can you think of cases other than those given above, where it is plausible to say that someone decides to believe? How rational are those cases?
(4) How plausible is Descartes' analogy between belief and action? If I
perceive that some action is good (e.g. donating to a charity), I can decide to
do it. I can also decide not to do it, and thereby fail to do something good, or
(worse) do something bad. If I perceive that some proposition is true (e.g. 2
plus 3 make 5) do I similarly decide to believe it? Surely not. Once I perceive
that it is true, I instantly believe it. There is a gap between perceiving that
some action is good, and doing it. There is no gap between perceiving that some
proposition is true, and believing it (see Williams, Descartes: The Project
of Pure Enquiry, ch. 6).
Some philosophers have denied that there is a gap between perceiving that
some action is good, and doing it. Plato, for example, thought that if you
perceive some action to be good, and fail to do it, that shows that you have not
fully perceived that it is good. It shows that you are still ignorant, in some
way. You will come across this influential view if you study Plato, and if you
study moral philosophy. If this view were correct, then action and belief would
be analogous, as Descartes claims. There would be no gap between perceiving an
action to be good and doing it; or between perceiving a proposition to be true,
and believing it. There would still be unresolved questions about the role of
freedom here, however.
Perhaps we should conclude that Descartes' theory of judgement is enormously
interesting and ingenious, but that its most plausible application is for some
irrational beliefs, not for beliefs in generaland not, in particular, for the
beliefs that are most central to his project, namely beliefs that are rational,
compelling, and indubitable.
FIFTH MEDITATION
The essence of material things, and
the existence of God considered a second time
We have seen that Descartes carefully distinguishes questions about a thing's
existence from questions about its essence, and answers these questions
separately. With respect to the 'I' of the Second Meditation, Descartes argued,
first, that the self exists; and second, that its essence is to be a thinking
thing. With respect to the wax, in the Second Meditation, Descartes argued that
essence of matter (of which the wax is an example) is simply to be extended and
changeable. With regard to God, in the Third Meditation, Descartes argued first
that the essence of God is of a being who is supremely perfect, infinite,
eternal, immutable, independent, powerful, and so forth. The idea of God
captures the essential nature of God. Descartes then argued that God exists, by
arguing that the idea of God that captures this essence must have God himself as
its cause.
In the Fifth Meditation Descartes returns again to the topics of matter, and God. Notice the title: 'The essence of material things, and the existence of God considered a second time'. As in the Second Meditation, Descartes considers the essence of matter, without yet addressing the question of whether material things exist. As in the Third Meditation, Descartes considers both the essence and existence of God, but with a new twist. Descartes argues that the essence of God cannot be known without knowing that God exists: God is a being whose essence implies his existence. This is the Ontological Argument for God's existence.
Descartes promises in the title that he will tell us the essence of material things. He asks 'whether any certainty can be achieved regarding material objects' (63), and the certainties he proceeds to discover in this Meditation concern geometry. He has a distinct idea of continuous quantity: something extended in space that can be measured in length, breadth, depth. He can clearly imagine 'various sizes, shapes, positions and local motions'. All of these ideas of extension are amenable to mathematical treatment. Various properties can be deduced from the concepts of these various shapes.
What has Descartes promised? Certainties regarding material objects (63).
What has he delivered? Certainties regarding geometry, and abstract mathematics
(65). He believes he has delivered exactly what he has promised, since geometry
describes the essence of matter. The essence of matter is to be extended, as we
know from the wax passage in Meditation II. Geometry describes all the truths
about extension. Geometry is the science of space. Matter and space are one and
the same, on Descartes' theory of matter.
Notice that there is nothing from the senses in this description of matter's essence. It is wholly abstract, wholly intellectualised. There is no talk of colour, or smell, or resistance, nor even talk of gravitational or magnetic force. Where will these fit in, on a purely geometrical conception of matter? The answer is, they won't. Descartes' conception of the essence of matter provides a graphic illustration of his rationalism: the properties of matter are the properties that extended substance can be proved to possess (see Williams, Descartes: The Project of Pure Enquiry, p. 231-2).
These reflections about the truths derivable from mathematical concepts lead Descartes to consider again the concept of God, and to ask what truths may be derivable from that concept. The concept of God is the concept of 'a supremely perfect being' (65). The essence of God includes every possible perfection. Existence itself is a perfection. A being that exists is more perfect than a being that does not exist. So the essence of God implies his existence.
This proof of God's existence does not depend on any claims about causality: it does not depend, for example, on the Principle of Causal Adequacy described in the Third Meditation. God's existence is deduced from his essence as directly as the properties of a triangle are deduced from its essence:
For most things, we must distinguish between the existence and the essence of the thing. But since God is the supremely perfect being, and since existence is a perfection, God's existence belongs to his essence. That, briefly stated, is the Ontological Argument. For a more detailed exegesis, and an evaluation, see Cottingham, Descartes, Blackwell, 1986, ch. 3.
Descartes concludes the Fifth Meditation by saying:
This is a puzzling passage. The idea seems to be that it is only because I
know that God is not a deceiver that I can trust the clarity and distinctness of
the ideas presented by my intellect. Knowledge of everything depends on
knowledge of God. This raises the famous problem of the Cartesian Circle, and
there are two aspects to the problem.
The first is that knowledge of the
existence and essence of the self, the essence of matter, the essence of God,
all depend on knowledge of a non-deceiving God. If that is so, how was thinker
entitled to reach conclusions about these topics prior to knowledge of a
non-deceiving God? This aspect of the problem was put by Mersenne, in the Second
Objections.
The second aspect of the problem is that knowledge of God itself depends on knowledge of God. This aspect of the problem is put by Arnauld, in the Fourth Objections.
How might Descartes respond to the problem of the Cartesian Circle? Have a look at his actual responses to Mersenne and Arnauld (140, 141, 246), in which he describes the role that memory plays in knowledge. Have a look also at the explanation and defence of Descartes given by John Cottingham, Descartes (Blackwell, 1986) ch.3.
(1) What, if anything, is missing in Descartes' conception of the essence of matter? The denial of sensory properties to matter, implicit in Meditation V, anticipates a thesis in Meditation IV about primary and secondary qualities (to borrow Locke's later label). See Williams, Descartes: The Project of Pure Enquiry, ch. 8.
(2) What, if anything, is wrong with the Ontological Argument, as Descartes
presents it? One of his critics, Gassendi, took objection to the idea that
existence is a perfection. He said it is not a perfection, but rather it is
'that without which no perfections can be present' (323). Gassendi is willing to
grant, for the sake of argument, that the concept of a supremely perfect being
'carries the implication of existence in virtue of its very title', but he
insists that this is a relation between concepts which implies nothing 'actual
in the real world'. He jokes that the concept of an 'existing lion' essentially
implies existence: but that does not mean there is an existing lion (99).
Similarly the concept of an existing God essentially implies existence: but that
does not mean that God exists. If you are interested in the Ontological
Argument, you will find more about it in the detailed debate between Descartes
and Gassendi, which also explains the relation of the argument to its Scholastic
predecessors. It was discussed and criticised by St. Thomas Aquinas. (See also
Cottingham, Descartes, Blackwell, 1986, ch. 3.)
It is only in this final Meditation that Descartes at last puts to rest the
sceptical doubt about the material world that he had raised in the First
Meditation. By the end of Meditation V, Descartes has partly rebuilt the edifice
of knowledge, if the arguments succeed. There is knowledge of the self, its
existence and essence; knowledge of God, his essence and existence; and
knowledge of matter, in so far as its essence is described by the intellectual
science of geometry. What remains to be established is knowledge of the
existence of matter.
The thinker begins by reflecting on the knowledge he has acquired of the
essence of matter. The fact that I have a clear and distinct conception of
matter as the subject matter of pure mathematics tells me that matter is at
least capable of existing: there is no contradiction in the idea of matter
(71-72). He then considers the fact that he is able to imagine things of all
kinds, including material things. My faculty of imagination seems to be not
purely a faculty of myself as thinking thing, but 'an application of the
cognitive faculty to a body which is intimately present to it, and which
therefore also exists' (72-74).
Imagining something is different to conceiving it in the intellect. Try to
imagine a figure with six sides, a hexagon. Can you do it? Most people are able
to form a mental image of a six sided figure. A different question: How many
angles does a hexagon have? Some people may answer this simple question by
simply reporting directly from their concept of a hexagon. Others may consult
their mental image, and count the angles on the imagined shape. Now try to
imagine a chiliagon, a figure with a thousand sides. Can you do it? Perhaps you
think you can: a shape with lots of tiny sides. Well, now imagine a shape just
like a chiliagon with one less side. Is it any different? Probably not. The
imagination doesn't have a fine enough resolution to provide a determinate image
of a chiliagon. Nevertheless, there is still the concept of a chiliagon,
provided by the intellect: and from the concept we could deduce all kinds of
geometrical truths, if we wanted to. This example is given by Descartes (72) to
illustrate his point that the imagination is something different to the
intellect.
Descartes thinks that the fact that our ability to imagine things is somehow
explained by the association of the mind with a body that is intimately
connected to it. However, the argument is not very clear, and Descartes himself
takes it to be inconclusive (73).
The next step is to remind the reader of the passage from the naivete of
common sense to the deepest scepticism, and the reader is reminded of the
arguments of the First Meditation, and indeed forewarned of the conclusions of
subsequent Meditations. This long section of the final Meditation is very useful
in helping to grasp Descartes' own understanding of his project of
methodological doubt (74-78), and his progress so far.
After this long explanation, the reader is suddenly confronted with an argument that is presented with a compression that is astonishing, given its importance. This is an argument for which Descartes is very famous indeed: an argument for dualism, or as he puts it, for 'the real distinction' between mind and body.
First, have a look at the conclusion of this argument. 'I am really distinct
from my body, and can exist without it'(78). The thinking self, whose existence
was proved in the Second Meditation, is wholly distinct from the body. It is a
thinking thing, a substance, which can exist without the body, the extended
substance, with which it happens to be contingently associated. Descartes is not
offering an argument for the immortality of the soul, but he does say in his
Synopsis that his argument paves the way for that conclusion. His opinion of the
relation of his argument to the question of immortality is summarized in the
Synopsis (13, 14). But leaving aside the question of immortality, the conclusion
that the mind is wholly distinct from the body is of enormous significance to
the philosophy of mind, both in Descartes' own time, and since.
The argument proceeds something like this. If I can clearly and distinctly
understand A apart from B, and vice versa, then A and B are metaphysically
distinct, and could exist apart. I can clearly and distinctly understand my mind
apart from my body: my mind, but not my body, is essentially a thinking thing.
And I can clearly and distinctly understand my body apart from my mind: my body,
but not my mind, is essentially an extended non-thinking thing. Therefore my
mind and body are metaphysically distinct and could exist apart.
The first premise just suggested does not capture quite what Descartes actually says, which is this:
But the mention of God can be taken as a metaphor about possibility, which
could be agreed to even by an atheist, which is why I rendered the principle in
the more neutral way given above. If I can clearly and distinctly understand A
apart from B, and vice versa, then A and B are metaphysically distinct, and
could exist apart. Notice that this is a classic example of rationalist
thinking: the reasoning moves from facts about the intelligibility of certain
concepts to facts about the metaphysics of the world. It moves straightforwardly
from facts about concepts to facts about the world. Recall that this kind of
move was just what annoyed Gassendi about Descartes' Ontological Argument for
God (where the concept of God was thought to imply the existence of God).
There is an alternative intepretation of this argument for the real
distinction between mind and body, which we can call the Argument from Doubt. I
can doubt that my body exists. I cannot doubt that my mind exists. Therefore my
mind and my body are not identical. Descartes is certainly committed to the
premises of this argument: but that does not mean he thinks that they support
the conclusion. On this interpretation, the argument looks very weak. Consider
analogous arguments, made in contexts involving ignorance. I can doubt that
Clark Kent can fly. I cannot doubt that Superman can fly. Therefore Superman is
not Clark Kent. Perhaps, however, the relation of mind to body is like the
relation of Superman to Clark Kent, namely the relation of identity. Clark is
Superman, but we don't know it. The mind is the body, but we don't know it.
Notice that in criticising the argument this way, we are not showing exactly
what is wrong with Descartes' argument. We are again using the argumentative
strategy of reductio ad absurdum: the strategy of showing that a
proposition, or an argument, has absurd consequences.
The Argument from Doubt is a poor one, but it seems poor as an interpretation of Descartes too. The first interpretation we considered is better, and is spelled out more fully in Margaret Wilson's analysis in her Descartes, ch.3. (Note, by the way, that there is an independent argument later in this Meditation for the real distinctness of mind from body (86), where Descartes tries to argue that the body is divisible; the mind is indivisible; therefore the body and the mind are distinct; and that despite this distinctness, mind and body are not related as a sailor to a ship, but rather form a 'unit'(81).)
The thinker now turns his attention to a mode of thinking which was
threatened by the early sceptical arguments he has reviewed, namely, sensory
perception (78). Perception yields ideas which seem to be ideas of existing
material things. Perception provides the hope for discovering not just the
essence of matter, but its existence. The argument appears at 79-80, and is
couched in the scholastic terminology of active and passive faculties. This
terminology is awkward, but not unclear: for 'passive faculty' read 'something
that is able to be affected'; for 'active faculty', read 'something that is able
to affect'; the terminology can then be discarded without much harm.
The argument focuses on the question: what is the cause of my ideas of
material things? and then proceeds something like this. I have ideas of material
things. These ideas must have a cause at least as real as the ideas themselves.
(This is the Principle of Causal Adequacy familiar from the Third Meditation.)
These ideas must be caused by either myself, God, or material things. They
cannot be caused by myself: for they 'are produced without my co-operation and
often even against my will'. They cannot be caused by God: for then God would be
a deceiver. The ideas must therefore be caused by material things. Therefore
material things exist.
Descartes focuses his attention once more on the sceptical hypothesis that these ideas of material things could be caused by dreams. Given the importance he assigned the argument in the First Meditation, and given its relevance to the plausibility of the preceding argument, Descartes deals with the problem rather briefly. He gives the common sense answer to the dreaming hypothesis: waking life has a coherence that dreaming lacks, so that when I am awake I can indeed know that I am awake (89, 90). The hypothesis that I am always dreaming is refuted by the knowledge that God would not permit me to be systematically deceived.
The meditative progress of the Meditations has come full circle. The thinker began as a naive believer in the existence of familiar material things: a bright fire, a snug dressing gown, crisp white sheets of paper. Recalling his pre-reflective period, Descartes says he had sensations of bodies,
All belief in familiar material things has been suspended for the course of the first five meditations. In the Sixth and final Meditation, knowledge is at last restored. Some things have changed, to be sure. In particular, the meditator has reached a certain conclusion about the hierarchy of knowledge:
However the beliefs 'that there really is a world, and that human beings have
bodies', beliefs which Descartes admits 'no sane person has ever seriously
doubted' (16)these beliefs, surely, are restored to their former selves.
Not
quite. The thinker has indeed argued for the existence of the material world,
but the conclusion to that argument was qualified. Although material things
exist,
Colour, taste, heat are not properties of corporeal things, but rather effects produced in us by things that are not themselves coloured, hot, etcin the same way that pain is clearly an effect on us rather than a property of things (82, 83). There is nothing in material things that resembles colour, bitterness, sweetness, heat, pain. The material things that cause the various perceptions 'possess differences corresponding to them, though...not resembling them' (81). All the vivid sensations encountered by his naive self, sensations of their hardness and heat, of light, colours, smells, tastes and soundsthe blue of the sky, the rich smell of the earth, the tang of the sea (75)these sensed qualities resemble nothing in the world. The material world whose existence he has triumphantly proven is a world devoid of the sensory qualities of colour, taste, smell, and sound. It is a world whose qualities are not qualitative, but quantitative: extension, and its modes of shape and size and motion.
This distinction is now known as the distinction between primary and
secondary qualities. (For its most famous exposition, see John Locke, Essay
Concerning Human Understanding II.viii. (1689)) What is Descartes' reason
for holding the distinction? It seems to have two sources, one from philosophy,
one from science. The philosophical motive is already evident. It is the
rationalist requirement that properties of things are given by what we can
clearly and distinctly conceive. The essence of matter will be those properties
that we can clearly and distinctly conceive. We can clearly and distinctly
conceive extension and its modes: we have a mathematical theory of space. We
have no equivalent for the sensory properties.
The scientific motive is different. It is not spelled out in the
Meditations, but it is one that can be shared by rationalist and
empiricist philosophers alike. It is a way of thinking about the world which
came with the scientific revolution, in which Descartes himself was an active
participant. It says: the genuine properties of matter are the properties
ascribed to matter by science. Physics, in the time of Descartes, was only in
its infancy, but already a revolution had begun. It began to seem that so much
more could be explained if one viewed matter as simply extended stuff in motion:
and it became possible to think of the material world in a unified way. The
behaviour of things is not to be explained by idiosyncratic substantial forms
that have nothing to do with each other (fire aims upward, earth aims downward),
but by universal laws governing all matter in motion, whether fire or earth. The
genuine properties of things are not the idiosyncratic sensory properties that
have nothing to do with each other (fire is warm, fire is red): there is the one
reality responsible for both sensations, namely matter in motion. The motion of
parts is too small for us to detect as motion: we see the motion as colour; we
feel the motion as heat. But viewed this way, the behaviour of all the bodies in
the world, including our own sensory organs, can be explained in the one unified
science. Physics has changed in its details since the time of Descartes, but the
central point is still the same: the world as physics describes it is not the
world as it is sensed.
The demon hypothesis of the First Meditation implied that things might be very different to how they appear. Descartes' Sixth Meditation says that things are, yet again, very different to how they appear. To be sure, the physical world matches our perception of it, in so far as our perception is of extension, shape, size, motion. But the naif of the First Meditation will never return to his comfortable common sense world of the blue skies, the dark earth, the tang of the ocean. The world to which he is reinstated is a world devoid of sensory properties, of colour and taste and smell. His banishment from the familiar world of the senses is not, this time, at the hands of the malicious demon, but at the hands of the well-meaning hero: the rationalist philosopher, and scientist, Descartes himselfthrough which the demon wreaks his vicarious revenge.
(1) Descartes argues that the mind and body are metaphysically distinct, and
could exist apart (78). How plausible is the principle on which the argument
rests? The principle, recall, is this. If I can clearly and distinctly
understand A apart from B, and vice versa, then A and B are metaphysically
distinct, and could exist apart. What is it to 'understand A apart from B'?
Perhaps it is to be able to grasp the concept of A without needing to think of
B. If you are not sure whether the principle is correct, test it by seeing if
you can find a counter-example: you would need to find an A and a B, such that
you can clearly and distinctly understand A apart from B, and vice versa, and
yet A and B are not metaphysically distinct, cannot exist apart.
Among the Greek philosophers were the harmony theorists, disciples of
Pythagoras, who said that a human being is like a musical instrument, a lyre,
something like a guitar. They said that the harmony of the lyre is a very
beautiful and complex thing, but it depends for its existence on a certain
arrangement of wood and strings. They said that the soul is like the harmony of
the lyre. The soul is a very beautiful and complex thing, but it depends for its
existence on a body. Their view, the harmony theory, contradicts Descartes'
conclusion about the metaphysical distinctness of mind and body. Modern day
theories of the mind tend to have much more in common with this ancient theory
of the soul than with Descartes' dualism.
Can you imagine how these philosophers might respond to Descartes' argument?
They might think that a musical instrument, a lyre or guitar, provided just the
sort of counterexample we were looking for. They might begin with some
conceptual analysis. What is a guitar, essentially? A guitar is essentially
something that is capable of making music, when played. If you couldn't play
music on it, it wouldn't be a guitar. What is a piece of wood, essentially? A
piece of wood is essentially something that came from a tree. If it didn't come
from a tree, it wouldn't be a piece of wood.
Now apply Descartes' argument to their example. If I can clearly and
distinctly understand A apart from B, and vice versa, then A and B are
metaphysically distinct, and could exist apart. I can clearly and distinctly
understand the concept of a guitar: a guitar is essentially something that is
capable of making music, when played. I can clearly and distinctly understand
the concept of a piece of wood. It is essentially something that came from a
tree. I can grasp the concept of a guitar without thinking of a piece of wood. I
can grasp the concept of a piece of wood without thinking of a guitar.
Conclusion: the guitar and the piece of wood are metaphysically distinct, and
could exist apart.
That conclusion is false. The guitar and the piece of wood are not
metaphysically distinct. They cannot exist apart. The guitar is the wood. When
the wood is smashed, the guitar is smashed. There is no chance that the guitar
will leave the wood, and float away to guitar heaven. The end of the wood is the
end of the guitar.
What implications does this have for Descartes' argument? When we find that an argument yields a conclusion that is false, we know that at least one of the premises is false. The premise about the concepts of guitar and wood seem reasonable. We can conclude that the culprit is Descartes' principle that conceptual distinctness implies metaphysical distinctness. The guitar and the wood are conceptually distinct: but they are not metaphysically distinct. We have found in the harmony theory a counter-example to Descartes' principle. This does not prove that a human being is like a musical instrument. It does not prove that the harmony theory is correct. It does not prove that Descartes' dualism is false. What it shows is that Descartes' argument does not support his conclusion. It is, for all we have shown, an open question whether some other argument will. (You will find the harmony theory discussed, and criticised, by Plato in his dialogue, the Phaedo.)
(2) What implications does the primary/secondary quality doctrine have for Descartes' proposed solution to the problem of error? If the doctrine is true, then it seems we are in serious error if we mistake secondary qualities for primary. Descartes has a response to this (82-83). He repeats that the senses themselves are not responsible for error, but rather a habit of making ill-considered judgments, which we can refrain from making. And he concedes that certain illusions (e.g. of the amputee) are the inevitable result of our mixed nature as 'combination of mind and body'. He insists that the senses as they are fulfill their practical function very well, of helping one to avoid harm. How adequate do you find that response? Is there any better response he could make?
[The end of Study Guide to Descartes' Meditations: Part III]]
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