Comments and Criticisms on Meditation VI
At the start of this Meditation, Descartes insists that imagination is different from pure
understanding (or intellection). This is important to the substance dualist since the
imagination, though mental, is clearly linked to physical objects via the senses (and
the memory of senses) whereas understanding can go on in the absence of physical
objects or their images: they are two quite different things.
Gassendi objected that Descartes has not done enough work to demonstrate that the
way we apprehend the world is different from ‘the brutes’ which, as in the Wax
Argument, perceive all that we do but lack any understanding. Gassendi said that
what is needed is an explanation for how the mind operates that is different from any
explanation as to how the brain operates – an explanation that Descartes has not
produced. Furthermore, Gassendi claimed that the mind is so much a part of the body
that it develops or deteriorates with the body: the two are, apparently, one and the
same.
Descartes has no real reply to either of these which does not beg the question. Firstly
that the mind can operate independently of the brain as, for example, when it judges –
something requiring no imagination. This is inadequate because he is assuming what
he wants to prove: he is assuming that it is the (bodily) brain that is necessary for
imagination but not for the mind itself. To Gassendi’s second point, he concedes that
the mind is less capable in an infant or in a drunk compared to a sober adult but this is
only so ‘when the mind is joined to the body…and uses the body as its instrument in
those operations in which it is usually occupied’. Again, he is assuming the
separateness of mind and body rather than explaining how this might be.
Returning to Descartes’ argument that there is something different between our
imagination (of a geometric shape, say) and our intellectual grasp of such a
geometrical figure, what can we say about his conclusion that the mind is essentially
only intellect? A point worth emphasising here is that Descartes was a scientist and
thought that physiological accounts could be provided for human emotions, sensations
and patterns of reflex behaviour – he was clear in his belief that certain mental things
were clearly linked to the physical world. On the other hand, he was insisting that
other mental functions – such as intuitive understanding and judgement – are wholly
distinct from such physiological explanations. Indeed, so distinct that any sort of
physiological explanation would be inappropriate. We might remind ourselves that
there are still a large number of people (including many philosophers) who hold that
no physical explanation can possibly give an adequate account of, say, consciousness.
Descartes’ argument for dualism
We saw that, in Meditation II, Descartes offered an argument for dualism which was
inadequate. Indeed, many philosophers think that Descartes was not committed to
this as an argument since it was so patently weak (especially so since Descartes seems
to take this line himself in replying to one of his contemporary critics, Arnauld). It is
here in Meditation VI that he develops a much stronger argument to the conclusion
that mind and body are different things (one that does not include a reference to being
able to doubt that his body exists unlike his mind).
He introduces this argument with the observation that God is capable of bringing
about anything that Descartes can clearly and distinctly perceive. What he has in
mind here are, for example, the rules of logic – thus, Descartes cannot conceive of
God as being able to exist and not exist simultaneously. Since God is not a deceiver,
Descartes can trust that such clear and distinct perceptions are true. The argument
then runs as follows:
1. If A can exist apart from B, and vice versa, A is really distinct from B.
2. Whatever I can clearly and distinctly understand can be brought about by God.
3. If I can clearly and distinctly understand A apart from B, then God can bring it
about that A and B are apart.
4. If God can bring it about that A and B are apart, then A and B can exist apart (and
hence, by 1., are distinct).
5. I can clearly and distinctly understand A apart from B if there are two attributes
such that I clearly and distinctly understand one of these applying to A and not B, the
other applying to B and not A.
6. Where A is myself and B is body, thought and extension satisfy the attributes
outlined in 5.
7. Hence, I am really distinct from body (and can exist apart from it).
One objection that has been made is that Descartes’ argument merely shows that mind
and body are only possibly distinct rather then really being so. This objection
fundamentally misses his point: he is claiming that two things really are distinct if it
is possible for them to exist in separation. Hence, actual distinctness does not entail
actual separateness.
A more telling objection is that the argument rests on the recognition of what
constitutes ‘clear and distinct perception’. As we saw in the comments and criticisms
on Meditation III, there are serious worries about whether such a criterion is anywhere
near an adequate ground for truth.
Another objection, due to Arnauld, is that Descartes is not entitled to conclude that
extension belongs essentially to body and not to mind. Descartes argued (in
Meditation II) that his essence is that of a thinking thing. Arnauld points out that it is
quite possible that Descartes’ clear and distinct perception that he is a thinking thing
is only part of his essence – that the rest of his essence may well include his physical
body. What Descartes cannot know is that his perception is complete, in other words.
In defence of Descartes we might point out that this cannot be known for any
philosophical account of mind – since to know that, we would have to have perfect
knowledge (which only God can have?). So, for instance, materialist claims that the
mind will prove reducible to the operations of the brain assumes that the evidence for
this (all the evidence) will one day be delivered up as science advances. Without such
an assumption, the materialist concept of mind is pretty empty. However, this is an
excuse for the inadequacy of Descartes’ claim and does nothing to strengthen it.
Another serious objection to Descartes’ position is one that came out when we looked
at criticisms of the Cogito argument: how does Descartes know that he is a particular
thing? He claims that he knows he is a thinking thing, indeed he is only a thinking
thing. He also implies that he knows himself as a continuing identical entity – a ‘self’
distinct from other selves. The problem is that Descartes provides no account of what
individuates one mind from anything else. Nor is it clear how one can move from the
generalities like ‘thought’ and ‘extension’ to the particular ‘self’ he claims to know.
Finally, he provides no basis for claiming that the self continues from moment to
moment (something which the materialist position finds straight-forward, for instance,
by identifying mind with body).
The reliability of the senses
In the middle of Meditation VI Descartes at last affirms that ‘material things exist’. It
is here that he treats the question of the truths that the senses deliver. What is to be
criticised is the vagueness of his treatment.
You will remember his dismissal of the senses as being useful for the truth in
Meditation I – since they have proved unreliable in the past, we would be imprudent
to rely (wholly) on them now or in the future. Here he retrenches from this position.
Firstly, he indicates that it is natural (part of the ‘teachings of nature’) to believe that
the senses give information of a physical world. Although he has learnt to mistrust
‘nature’ he cannot altogether rule it out as a reliable source of the truth. Secondly,
God would not have given him a faculty which would lead him into error if he used it
correctly. Thus, the reliability of his senses rests not on their inherent reliability (as
he criticised in Meditation I) but on the principle that God would not allow them to
deliver false knowledge.
He offers nothing else concerning the reliability of the senses for delivering
knowledge of physical objects. And notice that, if he cannot be certain of the
existence, and the goodness, of God then he cannot rely on his senses. As we have
seen, Descartes proofs of these are unconvincing and hence his argument here is
unsound.
The interaction of mind and body
The last part of the Meditation is occupied with Descartes’ discussion of the
interaction of mind and body. A major criticism of Descartes’ dualism is that he does
not offer a satisfactory account of how the unextended mind can influence the
extended body and vice versa. A second criticism is that he does not make it clear
where the mind is to be found – he says at one point that it is restricted to a small part
of the brain, and at another that it is ‘sort of intermingled’ with the whole body.
This first criticism points out the absurdity of the dualist’s position. Whenever I am
doing something – writing something down, for instance – there must be two parallel
things going on: my body doing the writing and my mind doing the thinking about
what I am writing. To the critic of Cartesian dualism, Gilbert Ryle, this concept of
mind is as of ‘the ghost in the machine’. He concluded that thinking of the mind as a
thing is a ‘category mistake’ – much like thinking that ‘team spirit’ would have to be
a thing rather than simply a property of an interaction of things.
The second criticism might be turned aside if we were charitable and allowed that
Descartes conceived of the mind and the body as some sort of third entity (despite
what he wrote in certain places). Thus, though God could make mind and body
separate, this is enough to justify their distinctness. However, in humans he has not
actually separated them and humans are special in having understanding linked to
imagination derived through knowledge of the physical world.
In doing this, however, we have lost the grounds for substance dualism, something to
which Descartes was clearly committed.