Think: A Compelling Introduction to Philosophy (10 page)

In the philosophy of mind the Leibnizian must deny the possibility of Zombies and Mutants. If the physical biography is fixed,
then the mental biography is fixed thereby. There is no independent variation, actual or possible. The philosophical problem is that
of understanding why this is so. It is a question of how to understand the way in which the entire physical story makes true the
mental story.

Locke thought he could leave it open whether it is an immaterial `thing' (a ghost) within us that does the thinking, or whether it
is the physical system itself, since God can superadd thought to anything he likes. But he is abundantly clear that it takes a mind to
make a mind. It takes a special dispensation: thought cannot arise
naturally (or, as Leibniz has it, in a rationally explicable way) from
matter.

For unthinking particles of matter, however put together, can
have nothing thereby added to them, but a new relation of position, which it is impossible should give thought and knowledge to them.

It is this kind of a priori certainty about what can and cannot cause
other things that marks Locke, like everyone else of his time, as
fundamentally a rationalist, albeit one who is more nervous about
our powers of reason than Descartes and Leihniz.

Thinkers about mind and matter have not got much beyond
Locke and Leihniz. Today as well there are thinkers (sometimes
called `new mysterians') who think we shall never understand the
relationship between mind and matter. It remains as Locke left it, a
rationally inexplicable matter-God's good pleasure. 'T'here are
even philosophers who think that some kind of Cartesian dualism
is true, and that the mind really is epiphenomenal-never causes
any physical events at all. They say this because they recognize that
the physical is a closed system. If there is a process that begins with
a pin being stuck in you and ends with a wince, then there is an entire physical chain from pin to wince that explains the wince. So,
they think, it has to be falsethat you wince because you are in pain.
This hit of common sense has to be given up. You wince because of
the physical pathways, not because of a mental add-on. These thinkers are in fact stuck with the same problem of interaction that
faces Locke. We discuss it more in the next chapter.

But there are other thinkers who think that a rational relationship can be made out. I shall introduce two broad approaches. The
first tries to give an `analysis' of the mental, in terms that enable us
to see it as a Leihnizian expression of the physical.The second tries
for a scientific kind of reduction or identity of the mental to the
physical.

ANALYSIS

Analysis, as philosophers aim at it, attempts to say what makes true
some mysterious kinds of statement, using terms from some less
mysterious class. Analysis is easily illustrated by a homely example.
Suppose someone becomes perplexed by that icon of modern
Western life, the average man, with his 2.4 children and 1.8 automobiles. How can this joke figure he of any real interest? The answer is given by showing what makes true statements couched in
terms of him: here that, across families, the total number of children divided by number of progenitors is 2.4, and automobiles
divided by number of owners is 1.8. This information is succinctly
presented in terms of the average man. He is what Russell called a
`logical construction' out of aggregates of facts. (This does not mean
that all statements about the average are sensible or useful: as has
been said, the average person has one testicle and one breast.)
Philosophers also talk of a reduction of statements of one kind to
those of another. Analyses provide the reductions.

Analysis tells us what is meant by statements made in one form
of words, in terms of statements made in other words. Its credentials as an intellectual tool have themselves been the topic of a great
deal of philosophical controversy, and its status has varied over the
last hundred years. Some, such as Russell and G. E. Moore (1873-
1958), thought of it as the essential goal of philosophy. Later, its
prospects were queried by the leading American thinker of the
mid-twentieth century, W. V. Quine (1908- ), and by others, and
their pessimism was given some credibility by the depressing fact
that very few philosophical analyses seemed successful. Currently
analysis is enjoying something of a cautious revival. But for our
purposes these methodological questions can he set aside. The
point is that if we can analyse mental ascriptions in physical terms,
then the Leibnizian dream of a rational or a priori way of seeing
how the physical gives rise to the mental is vindicated.

l.et us take pain as an example of a mental state. Suppose now we
try to analyse what it is for someone to he in pain. We identify pain
primarily in terms of what pain makes us do (which is also what it
is for, in evolutionary terms). Pain makes us do a variety of things.
It demands attention, it causes us to immobilize parts of the body,
distracts us from other things, and of course it is unpleasant. Suppose we can sum these consequences in terms of tendencies or dispositions to behaviour. Then the suggestion is that to be in pain
just is to be disposed in these ways. This is the analysis of what it
means, or what makes it true, that a person is in pain. This result
would bean a priori exercise of reason, brought about by thinking
through what is really intended by statements about this kind of
mental event. Then the mystery of consciousness disappears. You and your twin, since you share dispositions (you verifiably tend to
behave the same way), share your sensations, because this is what
sensations are.

This doctrine is called logical behaviourism. I believe there is
something right about it, but there are certainly difficulties. We
might object that we are familiar with the idea that people can
share the same sensation although they react somewhat differently. One can stub one's toe one day, and make a fearful fuss about
it, but do the same thing, and feel the same pain, another day and
bravely smile and carry on. Behaviour is not a transparent guide to
sensations, thoughts, or feelings. (That is the point of the joke
about two behaviourists in bed: `That was great for you, how was it
for me?') So, at the very least, complications must be added. Perhaps we could salvage the analysis in terms of dispositions to behaviour by pointing out that even if you bravely smile and carry
on, you are still in some sense disposed to more expressive demonstrations of pain that you are suppressing for one reason or another. It is almost impossible to suppress tendencies to pain
behaviour entirely, and other parties are very good at noticing the
difference between, for instance, a child who has not hurt itself,
and one who has but who is being brave. It seems essential to pain
that it disposes in this way. But even this much is sometimes challenged by cases of people with certain kinds of brain damage, who
apparently sincerely say that some pain is still present, but that they
don't mind it any more. We should notice, however, that it is quite
hard to make sense of that. If you give yourself a nice sturdy example of pain-touch a hotplate, or swing your toe into the wallit is very hard to imagine that very mental state without imagining it as incredibly unpleasant. And it is hard to imagine it without its
tendency to cause typical manifestations in behaviour.

Contemporary thinkers tend not to pin too much faith on
behaviourism of this kind. They prefer a slightly more elaborate
doctrine known as functionalism. "Phis too pays prime attention to
the function of the mental state. But it identities that function in a
slightly more relaxed way. It allows for a network of physical relationships: not only dispositions to behaviour, but typical causes,
and even effects on other mental states-providing those in turn
become suitably expressed in physical dispositions. But the idea is
essentially similar.

Pain is a mental event or state that lends itself fairly readily to the
project of analysis, for at least it has a fairly distinctive, natural, expression in behaviour. Other states with the same kind of natural
expression might include emotions (sadness, fear, anger, and joy all
have typical manifestations in behaviour). But other mental states
only relate to behaviour very indirectly: consider the taste of coffee, for example. To taste coffee gives us a distinctive experience.
"There is something that it is likefor us to taste coffee (not forLom-
hies). But it doesn't typically make us do anything much. Contemporary thinkers like to put this by saying that there are qualia or
raw feels or sensations associated with tasting coffee. And friends
of qualia arc often fairly glum about the prospects of reducing
qualia to dispositions in behaviour. As far as that goes, they are
back with Locke. As it happens, these qualia are superadded to various physical events-in my case, if not in yours-but it could have
been otherwise. But then scepticism whether you are Zombies or
Mutants again threatens.

A SCIENTIFIC MODEL

One distinction the contemporary debate is fond of making is important to notice. So far, we have presented Leibniz as opposing the
element of brute happenstance in Locke, in the name of a rational
quasi-mathematical relation between mind and body. It is possible
to suggest that there is a middle route: one that opposes the happenstance, but does not go so far as a mathematical or rationally
transparent relationship. This is usually put by saying that perhaps
there is a metaphysical identity between mental and physical facts
or events, but that it is not necessarily one that can be known a
priori.

A common analogy is this. Classical physics identifies the temperature of a gas with the mean kinetic energies of the molecules
that compose it. So in making hot gases God has only one thing to
fix: fix the gas and the mean kinetic energy of its molecules, and
this thereby fixes the temperature. There is no independent variation. There can't he Zombie or Mutant gases, in which the kinetic
energy of the molecules either issues in no temperature at all, or issues in different temperatures from those associated with the same
energy in other gases.

On the other hand it is not simply reason or thought or mathematics that enabled scientists to equate temperature with mean kinetic energy. The breakthrough was not a priori, armchair analysis
of what is meant by temperature, but took experiment and observation, and general theoretical considerations. The result was not
purely a priori, but at least mostly a posteriori. The relation is not
one that could be worked out in advance just by mathematics or by `clear and distinct ideas, like the fact that a circle on a tilted plane
casts an ellipse.

In general, in science, when one theoretical term or property,
like temperature, becomes identified with another (here mean kinetic energy of constituent molecules), the link is given by bridge
principles that are part of the theories of the sciences in question.
So, for example, the current identification of genes with hits of
1)NA happens because in classical biology genes are defined in
terms of their function in making characteristics heritable, and
now in molecular biology it turns out that bits of DNA are the
things that have that function. Notice that analysis is not entirely
absent. We have to know what genes are meant to do before the
equation can be made. But the big discovery is the contingent, scientific discovery of what it is that does what they are defined as

If we modelled our approach to the mind-brain problem on scientific reductions of the kind just described, we would find some
physical state characteristic of people sharing some mental state.
So, for instance, we might find that all and only people in pain
share some brain state (often indicated vaguely by saying that their
`C-fibres are firing'). And then it would be proposed that this then
is the state of being in pain, just as some bits of I )NA are genes.
Once again, there would be a complete reduction of the mental to
the physical.