In this chapter and the next I shall be considering two
topics which are widely regarded as raising difficulties for physicalism. This chapter will be concerned with
mental representation. The next chapter will deal with consciousness. It is not
difficult to see why mental representation is often thought to present a
problem for physicalism. Mental states like beliefs,
desires, hopes, fears, and the other propositional attitudes have
representational contents: they represent the world as being a certain
way. But how can this be, if such mental states involve nothing more than
physical states of the brain? If my belief that Lima is the capital of
Peru is realized by an arrangement of neurones, then
how does this belief manage to reach out across the world and latch on to a
city I have never seen? How can a bank of neurones
be about something outside my head?1
Different ph ysicalist theories of
mind, such as functionalism, or Davidsonian anomalous
monism, or any of the many other physicalist accounts
of mind currently on offer, will make this problem precise in rather different
ways. However, since my aim in this chap ter is
to defend a positive solution -- the teleological theory of representation --
which will be available to physicalists of all kinds,
it will not matter greatly exactly which version of physicalism
we start with. So I shall follow the pattern o f much recent literature,
and start once more with functionalism.
The overall plan of this chapter will be as follows. In
the next section (3.2) I shall show how repesentation
arises as a problem for functionalism, and offer the tel
eological theory of representation as an initial
solution. Then, after some brief comments about broad propositional
attitudes (3.3), I shall elaborate some of the details of the teleological
theory, in the course of answering the standard objection that some beliefs
serve biological purposes even when they are false (3.4). This will
prompt some discussion of the status of belief-desire psychology (3.5), and
also show how the teleological theory incorporates, rather than competes with,
the ide a that truth
guarantees the satisfaction of desires (3.6). Sections 3.7-10 will then
defend this satisfaction-guaranteeing component in the teleological theory
against a number of objections, and will also consider some alternative
theories which sh are this satisfaction-guaranteeing
assumption, but do not incorporate it within a teleological context.
After this I shall return to the issue of broad beliefs, showing how it is
unsurprising, given the teleological theory, that beliefs and desiress hould fail to supervene
on brain states (3.11-12). The final two sections of the chapter will
then discuss the availability of empirical evidence for the teleological theory
(3.13), and point out the radically anti-verificationist
implications of th e theory
(3.14).
Functionalism views beliefs and desires and other mental
states as internal causal intermediaries between perception and behaviour. For functionalism, w e might say, beliefs
and desires are part of a system of internal pushes and pulls which explains
why people behave as they do. This functionalist picture of mental states
raises immediate questions about representation. After all, why should
components in an internal causal structure be credited
with representational powers? Surely an internal causal role is one
thing, and a representational relationship to an (almost
invariably) extra-cranial state of affairs another. Functionali sm seems to describe
only the first, causal aspect of mental states, and to omit the second, representational
aspect. As it is sometimes put, functionalism seems to give us only the
"syntax" of mental states, and to leave out their
"semantics".
It is true that most versions of functionalism follow everyday
practice and identify beliefs and desires in terms of "content
clauses", as the belief that p, the desire that q, and so on.
However, from the perspective of the rest of the functionalist package, this
need only be viewed as the most convenient among many possible ways of indicating
the causal structure of beliefs and desires, as one way of "labelling" causal roles, and not as an essential use
of representational notions.&nb
sp; After all, how could representational relationshipships
to often distant states of affairs be intrinsic to the internal causal roles of
mental states?
It is perhaps worth pausing on this point. Despite what I
have just said, doe sn't the functionalist approach
to the mind need to invoke assumptions about what desires are for and beliefs
are about, in order to infer what agents will do? Well, functionalism
does indeed attend to the causal roles of mental states;
and, a s I have just said, it does take these causal roles to be indexed
by content clauses. But, to repeat, it is not essential to this that the
content clauses specify what beliefs are about or desires are for. A nice
way to bring this out is to th
ink of contents, as some philosophers do, in terms of sets of possible
worlds. On this account, the content of an instrumental belief that F
will cause G is the set of worlds in which F does cause G, and the content of a
desire for G is the set of w orlds in which G
obtains. Given this, and given that agents tend to perform those actions
that they believe are necessary for what they want, functionalism could then
invoke, as a first aproximation, the generalization
that an agent will do F just i n case the set of
worlds which comprises the content of the agent's desires is contained in the
set of worlds which comprises the content of the agent's instrumental beliefs
about F. Note, however, that it does not matter to this generalization
that these beliefs and desires represent the world as being a certain way --
that they are true (in the case of beliefs) or satisfied (desires) just in case
the actual world is a member of the set of worlds which constitutes the
content. All the general ization needs are the
overall sets of worlds which comprise the contents, since these alone suffice
to specify the interdependent causal roles of beliefs and desires; it is irrelevant that these contents also determine,
together with the actual worl d, whether beliefs are
true or desires satisfied. Which is why, from the functionalist point of
view, any other similar structures could in principle serve to specify causal
roles instead, even if they didn't involve the entities we normally think o f
beliefs and desires as about -- provided, that is, that they at least succeed
in tying mental states to the bits of behaviour, the
Fs, which are the end points of the causal roles the functionalist is
interested in.
So the complaint is that functionalism gives only internal
causal roles, and not representation. It might seem to some readers,
however, that the difficulty is easily remedied. Isn't the trouble just
that functionalism thinks of the "inputs" and "outputs" of caus al roles too narrowly, with inputs starting with the
sense organs, and outputs finishing with bodily movements? So why not
simply extend our causal net to allow more distal causes of perception, on the
input side, and more distal effects of behaviou r, on
the output side? This would allow us to analyse
the truth conditions of beliefs as those distal circumstances which cause them,
and the satisfaction conditions of desires as those distal states of affairs
they give rise to, and would the reby seem to
reintroduce aboutness without further ado.
This move, however, is fatally afflicted by the disease known
as "disjunctivitis".2 The belief that there is
an ice-cream in front of you can be caused, not on ly
by a real ice-cream, but also by a plastic ice-cream, or a hologram of an
ice-cream, or so on. So, on the current suggestion, the belief in
question ought to represent
either-a-real-ice-cream-or-a-plastic-one-or-any-of-the-other-things-that-might
-fool-you. Which of course it doesn't.
Similarly with desires. The
results which follow any given desire include not only the real object of the
desire, but also various unintended consequences. So the current
suggestion would imply that the object of any desire is the disjunction of its
real object with all those unintended consequences. Which
of course it isn't.
So, even if we widen functionalism's causal roles to include
distal causes and effect s, we still need somehow to winnow out, from the
various causes that give rise to beliefs, and the various results that
eventuate from desires, those which the beliefs are about, and which the
desires are for.
This is where an appeal to teleological considerations seems to
yield a natural and satisfying answer. We can pick out a desire's real
satisfaction condition as that effect which it is the desire's biological
purpose to produce. And, similarly, we can pick out the real truth
condition of a belief as that condition which it is the biological purpose of
the belief to be co-present with.3
This teleological theory of representation will be elaborated
and defended in detail in what follo ws. But at this stage let me make two immediate
points. First, my use of "purpose" and similar phrases should
be understood, as in chapter 2, in terms of the aetiological
account of teleological notions. That is, I take it that the purpo se of A is to do B just in case A is now present
because in the past some selection process selected items that do B. So,
in the specific context at hand, when I speak of that condition which it a
desire's biological purpose to produce, I take it th
at some past selection mechanism has favoured that
desire -- or, more precisely, the ability to form that type of
desire -- in virtue of that desire producing that effect. And
when I speak of the condition which it is the bio logical purpose of a belief
to be co-present with, I take it that some past selection mechanism has
selected that belief -- or, more precisely, the ability to form that
belief type -- in virtue of its occurring in conjunction with that
condition. (As in chapter 2, those readers who dislike the aetiological analysis of purposive talk can simply replace
all my references to purposes by references to selection mechanisms. What
matters to my story is that mental states shou ld be the products of selection processes, not what
terminology we use to specify this.)
The second immediate point I wish to make is that this selectionist-teleological approach to mental representation
does not imply that all representa tional abilities must be genetically innate products of
inter-generational selection. For selection-based teleology can also be a
product of individual learning (cf. "The pigeon is pressing the bar in
order to get food"). And so, if some non-i
nnate belief or desire is selected in the course of
individual learning in virtue of the condition it is co-present with, or the
result it gives rise to, then that belief or desire will have a genuine
selection-based representational purpose, despite its non-innateness.
It will be helpful, before proceding
to further details of the teleological theory, to comment briefly on the
relation between my argument so far and the recent
debate about "br oad"
versus "narrow contents". My reference, in the middle of the
last section, to the possibility of "widening" the functionalist net,
may have made some readers think of recent philosophical discussions of
"broad contents". However, our curr ent concerns are rather more
general than the debate about broad contents. Our present topic is to
understand content as such: why do mental states, of whatever kind, have
contents? The debate about broad contents, by contrast, takes the
existence of contents as such for granted, and is concerned with more detailed
questions about which specific mental states have which specific contents.
The debate about broad contents arises from the observation, to
which I drew attent ion in chapter 1, that the
content of many beliefs seems to depend, not just on the believer's physical
make-up, but also on features of the context. Thus Hilary Putnam has
argued that the identity of beliefs about natural kinds depends on what kind s
are actually present in the believer's world (1975);
Tyler Burge has argued that the contents of theoretical beliefs can
depend on features of the social context (1979, 1982); and Gareth Evans
has maintained that the possession of singular b eliefs
demands the existence of the objects those beliefs are about (1982).
These philosophers and their followers form one side of the
debate about broad contents. On the other side is a sizeable minority who
are suspicious of broa d beliefs, on the grounds,
roughly, that it is hard to see how differences which lie outside the head can
matter to the explanatory significance of mental states (cf
Fodor, 1987).
This is why I said the debate about broad contents is less
general than our current concerns. The participants in the debate take it
as given that our beliefs and other attitudes have representational
contents. The point of dispute is only whether or not these contents are
fixed by internal physical make-up.
John McDowell (1986, sect 5) has suggested that it is only
possible to get worried about the general possibility of representation if you
make the mistake of thinking that all beliefs are narrow. McDowell's
thought is that a problem about representation only arises as long as we think
of beliefs as things inside people's head. Once we recognize that the
very possession of a belief can involve extra-cranial facts, we ought no longer
to be puzzled about how things insid e the head can
stand for things outside.
This seems to me to get things exactly the wrong way
round. Merely accepting that the possession of beliefs involves entities
outside believers' heads does little to explain how representatio
n as such is possible. After all, plenty of the other states that people
possess involve entities outside their heads --
for example, financial solvency, or popularity, or being married --
without thereby becoming representat ional.
Far from appealing to broad contents to dissolve the general
problem of representation, I think we will do better to solve the general
problem of representation first, and then apply the solution to the issue of
broad contents.&nbs p;
In the absence of any general understanding of representation as such, much of
the current debate between the friends and enemies of broad contents has
collapsed into an indecisive trading of intuitions. However, once we have
arrived at a satisfa ctory
general theory of content, then we shall understand why it is quite
unsurprising that some contents should be broad. I shall return to this
issue in section 3.10 below.
A good w ay to develop the details of the teleological
theory is to consider a familiar objection. This is the objection that
certain beliefs have biological purposes which require them to be present when
they are false, and so constitute prima facie counter -examples to the
teleological thesis that truth conditions can be analysed
as those circumstances in which beliefs are biologically supposed to be
present. (Ned Block has urged this objection on me. See also Stich, 1982, p 53.)
; For example, consider the belief that you are not going to be
injured in some unavoidable and imminent trial of violence. It is
arguable that natural selection has bequeathed us an innate disposition to form
this belief, even in cases where it hig hly likely that we will in fact be injured, in order to
ensure that we will not flinch in battle. But it then seems to follow
that, according to the teleological theory, the truth condition of this belief
will include many cases where we will be inj ured -- since such
cases will be among those where we are biologically supposed to have the
belief. So we seem to have a reductio of the
teleological theory. For by hypothesis the truth condition of the belief
is that we won't be i njured.
Examples like this are interesting, but I don't think they
suffice to discredit the teleological theory. In order to see why not, we
need to consider the way that beliefs and desires combine to generate actions
in the overal l human decision-making system.
It will emerge that the purpose of beliefs in this system is to guide actions
in such a way that desires will be satisfied. And then, by understanding
the teleological theory as focusing on this specific purpose of beliefs, we
will be able to accommodate examples of the above kind. The point will be
that stopping you flinching is a special kind of biological purpose, which cuts
across the purpose of satisfying desires,4
and which therefore does not require the truth of beliefs in the way that the
satisfaction of desires does.
The overall biological function of the human decision-making
system is to generate actions that cause biologically suitable results.
Beliefs an d desires both contribute to this
purpose. However, they contribute in different ways. The role of
desires is to do with the fact that different results are suitable at different
times: our desires vary in order that our actions will pro duce different
results at different times. The role of beliefs is to do with the fact
that, given any result, different means are appropriate to that result at
different times: our beliefs vary in order that we can choose the most
effective me ans at any time to the results that we
desire at that time.
In the end, all selection-based purposes depend on results: to have a
purpose is to have been selected by a mechanism which favours
certain results. However, the above remarks show that this is true of beliefs
only in an indirect sense. For beliefs don't have any results of their
own. Rather, their standard purpose is to produce whichever results will
satisfy the desires they are acting in concert with.&nb sp; In effect, beliefs get selected at one
remove, in virtue of being good at causing actions which cause desired results.
Note that this means that, according to the teleological
theory, there is a sense in which the representational pow ers of desires are
prior to those of beliefs. Any given desire will be present in order to
produce a certain result r, which result is therefore its satisfaction
condition. Given this explanation of satisfaction for desires, we can
then explai n the purposes of beliefs. Any
given belief will be present in order to produce actions which will produce
desired results if a certain condition p obtains, which condition is therefore
that belief's truth condition.5
Let us now return to the example with which I began this
section. I have just argued that the biological purpose of any belief is
to be present in those circumstances in which the actions it prompts will
satisfy desires -- which circumstanc es therefore count as
its truth condition. However, the example about not flinching in battle
involves a different kind of purpose. For in this case the belief at issue,
the belief that you won't be injured, has a extra biological purpose, apa rt
from its role in aiding the satisfaction of desires, namely, to ensure that you
do not flinch in battle.
In order to deal with such examples, we need to distinguish the
"normal" purpose of beliefs, namely, to ensure the satisfaction of
desires, from such "special" purposes as stopping you flinching in
battle. This distinction then allows us to frame the teleological theory
in a way which is consistent with the existence of such special purposes.
That is, we should understan d the teleological
theory as relating specifically to the normal purpose of beliefs. For, as
long as we stick to those normal purposes, then truth is still the requirement
for achieving them, in line with the teleological theory of representation.6
If you are unconvinced that the belief about invulnerability
needs to be true in order to serve its "normal" function, consider
the case, say, of Cuthbert Coward. Cuthbert would far rather remain
unscratched th an win the
battle. Still, if Cuthbert were somehow to be persuaded that he won't be
injured (though in fact he will), then even he might be induced to enter the
fray. But then he won't get what he desires, which is above all to remain unscathed.&nbs p; It is only the special purpose of
getting him to fight, even though he's doesn't really want to, that gets
satisfied when the belief is false. By contrast, the normal purpose, of
satisfying his desire to remain unscathed, still requires his belie f to be
true -- just as the teleological theory,
as now proposed, requires.
Of course, Cuthbert has somewhat unsatisfactory desires, from a
biological point of view, in the sense that the satisfaction of his desires is unlikel y to further his overall chances of survival and
reproduction. This is why beliefs sometimes have special purposes.
The point of these special purposes is in effect to by-pass the normal role of
beliefs in satisfying desires, and to ensure ins tead that agents with biologically inappropriate desires
don't end up performing biologically inappropriate actions. Cowards are a
case in point. Their unfortunate desires mean that they are likely to end
up running from battle, and thus losin
g the any chance of biologically important spoils, just in order to avoid a
scratch. And so, in order to protect them against the biological dangers
of such consequences, natural selection predisposes them to believe that they
are invulnerable, even when the evidence doesn't warrant this belief, so as to
stop them performing those actions which would in fact satisfy their desires.
It might seem puzzling that natural selection should give some
beliefs two different purposes. Af
ter all, natural selection presumably designs
biological systems for one ultimate end, namely, the bequest of genes. So
why don't beliefs simply have the single purpose of ensuring such gene
bequests?
The answer relates once more to the nature of the human
decision-making system. Note that this system doesn't work by always
choosing that action which is most likely to ensure gene bequests. Rather
it chooses that action which is most likely to satisfy existing desires.&nb sp; It is not
impossible to imagine biological systems of the former kind, which always aimed
directly for gene bequests. But it seems likely that the limitations of
our cognitive capacities have prevented us from doing things in this way.
Ins tead we aim for such
relatively short-term goals as warmth, sex and chocolate ice-cream.
By and large such short-term goals correlate reasonably well
with ultimate biological success, which is no doubt why our innate desires, and
our ways of acquiring non-innate desires, have evolved as they have. But
the satisfaction of our desires won't always coincide with biological success
(not all sex leads, or even can lead, to reproduction). And this then
means that there are certain b iological risks
consequent on our way of doing things. Now, it may be that some of these
risks are inevitable by-products of our desire-based decision-making
system: for example, it may be inevitable that humans will have extremely
strong desi res to avoid
injuries, and so inevitable that in certain circumstances this will lead them
to act against their biological interests. And this will then lead to
natural selection interfering with the normal operation of decision-making
system, by gi ving us
beliefs which lead us to act in ways that frustrate our desires, but satisfy
our biological needs.
Let me sum up the argument of this section. Certain
beliefs do indeed have some biological purposes that require them to be f alse. However, this doesn't invalidate the
teleological theory of representation. For we can
understand the teleological theory as focusing specifically on the normal
purposes of beliefs, namely, to guarantee the satisfaction of desires.
And these normal purposes don't ever require beliefs to be false.
In the last section I made a number of definite assumptions
about the role of beliefs and desires in our o verall
decision-making system. Some readers may want to ask how this tallies with the agnostic attitude to everyday
psychology I expressed in chapter 1, when I said that my references to the
entities of everyday psychology should be understood merel
y as place holders for the true theoretical explanation of human cognition,
whatever that may be.
One possible response to this query would be to maintain that
the last section's comments about the roles of beliefs and desires need not be
read realistically, as committing me to substantial claims about the causal
structure of our cognitive system. Daniel Dennett, for instance, argues
(1971, 1978, 1987) that everyday psychology commits us only to the "intentional
stance", to the view that an individual's behaviour
is somehow appropriate to his or her environment and needs, and not to any
"design" or "physical" assumptions about the mechanisms
that might be responsible for generating that behaviour.
Dennett holds that this inten tional
stance is underpinned by general evolutionary considerations, which tell us
that our cognitive systems must have some design that will enable us to choose
actions that will further our welfare, while leaving open the internal details
of that design . On Dennett's conception, then, references to such
everyday concepts as belief and desire need not be taken as realistic
hypotheses about internal structures, but simply as a way of pointing to the approriateness of actions.
Howeve r, I shall not take this Dennettian line. For one thing, it sits ill with the
teleological theory of representation. According to the teleological
theory, the representational contents of beliefs and desires depend on how (the
abilities to for m) these states have been shaped by natural selection.
But if beliefs and desires aren't real states, but only constructs by which we
indicate the appropriateness of actions to circumstances, then it is hard to
see how natural selection can operate on them. Natural selection favours things which produce certain effects. But it
can't favour things which don't exist.7
In any case, there is good reason to doubt Dennett's view that
everyday psychology is restricte d to the
"intentional stance". This relates to a point made in the last
section. As we saw, natural selection hasn't arranged our brains so that
we always choose actions that are likely to maximize gene bequests.
Instead it has fixed on certain relatively short-term goals, like warmth and
sex, and on certain ways of acquiring further short-term goals, and arranged
for our brains to choose actions which are likely at least to satisfy these
goals.
As I observed at the end of the last section, this makes sense
from the point of view of natural selection, given that these short-term goals
correlate reasonably well with long-term reproductive success, whereas aiming
directly for such long-term reproductive success would no do ubt overtax our cognitive capacities (not to mention the
cognitive capacities of our evolutionary ancestors). But the fact that
the installation of short-term desires constitutes a sensible strategy from the
point of view of natural selection should n't obscure
the fact that it is a definite design option, a choice of one among a number of
different possible internal structures which could ensure that behaviour is more or less appropriate to needs and
environment. After all, we can easily enoug h
imagine hyper-intelligent non-human beings whom natural selection had made
"super-rational", by giving them no short-term desires as such, but
simply the sole aim of maximizing gene bequests by always choosing that action
which available information ind icated
as most likely to achieve that end. And, at the other extreme, we already
have terrestrial examples of simple organisms, like insects, with plenty of
hard-wired routines driven by short-term needs, but scarcely any ability to
modify their beh aviour in
response to information about the environment.
So everyday psychology, with its distinction between beliefs
and desires, takes us beyond the thought that evolution has somehow arranged
that we will choose actions appropriate to our needs and environment, to a
specific theory of how evolution has arranged this: evolution has
arranged for us to have information about our circumstances, in the form of our
current beliefs, and then to choose actions which those beliefs indicat e will satisfy the goals signalled
by our current desires. In these respects we are different from the
"super-rationalists", since they are not interested in any
intermediate goals except gene bequests; and we
are different from the insects, i n that their behaviour is almost entirely insensitive to information
about their circumstances.
In the light of these points, I accept that my appeal to
beliefs and desires in the last section does indeed take me beyond the stance
of chap ter 1, and commit me to the truth of certain
basic everyday psychological assumptions as realistic hypotheses.
However, now that we have seen why this commitment is inescapable, we can also
see why it is unburdensome. For there is plenty
of un contentious empirical evidence that everyday psychology is true at just
those points where it takes us beyond Dennett's intentional stance. The
significant point is not just that everyday psychology says that we are
different from the super-rational ists and the
insects in having an internal structure of beliefs and desires; in addition, our actual behaviour
shows that we are different in this respect. If we didn't differ from the
super-rationalists in having desires, then we wouldn't con tinue
to act in pursuit of short-term aims, like eating chocolate, even after we know
that doing so only makes us fat and so is no help to our reproductive success; and if we didn't differ from the insects in having
beliefs, we wouldn't be able to f igure out that one
way to acquire some chocolate would be to go to the new confectionery shop
around the corner.8
This kind of general evidence does not of course confirm every detail of the complex set of assumptions and
attitudes which constitute our everyday psychological thinking. But it
does seem to me to be enough to justify the kind of core assumptions about the
existence of beliefs and desires that I made in the last section.
Empirical psychology still has much to discover, both about the more detailed
claims made by everyday psychology, and about the "sub-personal"
structures by which such everyday psychological claims are implemented.
But I don't think it need do anything further to establish t hat human acions are generated by internal causal processes involving
beliefs and desires. If our actions were not generated in this way, we
would behave quite differently from the way we know we do behave.9
In section 3.4 I stressed that the teleological theory of
representation needs to be understood as focusing specifically on the role that
beliefs play in facilitating the satisfaction of desires, rather than on any
further role they may have in fulfilling further biological purposes. However,
once we focus on desire satisfaction in this way, then do we still need
teleology to explain truth-conditional content? Why not simply explain content
directly, by saying it is that property of beliefs which will ensure the
satisfaction of desires?
At the beginning of this chapter I argued that functionalism leaves
out representation, and that the teleological theory is needed to bring it back
in. But perhaps the moral of my remarks in 3.4 about the relation between
belief content and desire satisfaction is that we shouldn't start with
functionalism in the first place. For what those remarks in effect show is that
functionalism presents only a limited picture of the role that mental states
play in psychological explanation, a picture which leaves out the role of truth
in ensuring the satisfaction of desires. Perhaps once we fill in the missing
components of the picture, we won't any longer need teleology to explain
representation.
In due course I shall show that this is not so: even after we
have paid due accord to the role of truth in ensuring desire satisfaction, we
will still need teleology for a full explanation of representation. But it will
be worth proceding slowly.
The limitations of functionalism can be brought out by contrasting two
different pictures of the structure of action explanation. The first
picture, the picture embodied in functionalism, focuses on the internal roles
that beliefs and desires play in causing behaviour,
and so takes psychological explanation to conform to this pattern:
(A) X desires G
X believes that F will produce
G
___________
&n bsp;
X does F.
However, there is also a second picture of the structure of action
explanation, a picture embodied in my remarks about the human decision-making
system. According to this pict
ure, psychological explanation is not solely an
internal matter, but also has an "external" structure, which
explains, not behaviour, but the achievement of
results:
(B) X desires G
; X believes, of some behaviour, that it will
produce G
This
belief is true
__________
X achi eves G.
If we restrict our attention to "internal"
explanations of form (A), as functionalism does, then it scarcely surprising
that we become puzzled about the significance of representational notions,
since the only role that beliefs an d desires play in (A) is that of causal
pushes from the inside, as it were, and not as representers
of the external world. But in "external" explanations of form
(B), the representational features of beliefs and desires become crucial:
the sat isfaction condition of the desire specifies
what external result is at issue, the truth condition of the belief specifies
how things must be to ensure this result, and the actual truth of the belief
specifies that things are indeed so. Far from bein
g limited to the internal causes of behaviour,
explanations like (B) specify that external circumstances are such as to lead
from the agent's behaviour to result G.
This is why we now need to ask whether we really need to appeal
to teleol ogy in our theory
of representation. The original puzzle that led us to this theory was, in
effect, that internal explanations like (A) make no use of representational
notions. But now we see that external explanations like (B) do use represen tational notions.
And this suggests that we might be able to analyse
representational notions purely in terms of the way they enter into such
external explanations -- explaining truth, say, as that property which ensures
desire satisfaction -- witho ut
needing to appeal to teleological considerations after all.
In a moment I shall explain why this doesn't quite work. But
let me deal with a minor point first. There is a
extensive literature on the question of whether representat
ional notions are essential to (B). (See Loar 1981; Devitt, 1984; Field,
1986.) Can't an explanation like (B) always be replaced by a
two-stage explanation which first explains behaviour
F, as in (A), and then explains G by reference to the fa
ct that F causes G, and thereby omits any explicit mention of truth?
Well, maybe so. But the obvious question is why we should want to
dispense with truth in this way. The answer, for most of the
contributions to the relevant literature, is to do with
"deflationary" or "minimalist" theories of truth:
defenders of such theories are committed to the replacability
of (B)s by (A)s, since they think that mention of
truth is always simply a "quotational"
variant of what can be said in di squoted
terms; while opponents of such theories want to show that (B)s involve ineliminable appeal to truth as a real property of
beliefs. My present concerns, however, are orthogonal to this
debate. I am not concerned to decide how far talk of truth might be
eliminable in favour of something else, but simply to
take it at face value, and understand what work it does in our thinking about
the world. The question at hand is not whether we can do without truth,
but what we do with it . (As it happens, I think
that replacing (B)s by (A)s loses sight of a general
explanatory pattern, the pattern displayed in schema (B). On the other
hand, I don't think that this is the most effective way to argue against the
deflationary the ory, given that arguments based on
the importance of explanatory patterns are notoriously inconclusive. A
better strategy is to press the deflationalist for a
theory of translational content. I shall return to this issue in section
3.9 below.)
The question currently at issue is whether we can analyse representational notions simply on the basis of the
way that they enter into external explanations like (B), and without appeal to
teleological considerations. Let us consider in more detail how this
might work. The idea, in outline, is that truth conditional content might be analysed in terms of the role of truth in ensuring desire
satisfaction. We can formulate this suggestion explicitly as follows:
(C) The truth condition, for any belief, is that
condition which guarantees that actions based on
that belief will satisfy the desires it is acting
in concert with.
Something like this success-guaranteeing analysis of truth has
been p roposed by a number of other writers (Ramsey,
1927, p 29; Putnam, 1978, part 3; Appiah 1986; Mellor
1988; Whyte,
1990.) However, there is an obvious reason why it is not, as it stands,
an adequate substitute for the teleological theory. Namely, that it explains
truth, for beliefs, only by assuming the notion of satisfaction, for
desires. Yet satisfaction is as much a representa
tional notion as truth, and so ought itself to be
explained by an adequate philosophical theory of representation.
It is no good simplying offering an
account of desire satisfaction parallel to (C), such as:
(D) The satisf action conditon of a desire is that
condition which is guaranteed to result from
actions based on that desire, if the beliefs
behind
the action are tr ue.
For simply adding (D) to (C), without offering any further hold on
representational notions, is like trying to solve a single equation with two
unknowns. Both (C) and (D) are expressions of the principle:
(E) Actions based on true beliefs will satisfy the
desires they are aimed at.
(E) places a mutual constraint on the
representational values that a person's beliefs and desires can have. But
on its own it does not suffice to pin do wn those
values uniquely. If a given attribution of truth and satisfaction
conditions satisfies (E), then so will any attribution that simply permutes
referents for names and predicates, provided it does so in the same way in both
truth and satisfac tion
conditions. (Cf Stalnaker, 1984, pp 17-18; Papineau,
1984, p 555.)
This means is that any theory of representation that explains
truth by (C) needs to add something further --
not just (D) -- to explain satisfaction. I add teleology.
I explain desire satisfaction in terms of the results that desires are
biologically supposed to produce, and then plug this into (C), thus giving
truth the biological purpose of satisfying desires.
There are perhaps other possible options at this point. You
might agree with the success-guaranteeing account of truth, as in (C), and
agree that something extra is needed, yet disagree that the requisite addition
is teleology. However, let us postpone the question of whether (C) can be
appropriately supplemented in non-teleological ways until the section after
next. For the prior question is whether (C) is even
defensible as part of a full account of representation. There a
num ber of standard objections to the idea that truth
is what guarantees desire satisfaction, which both the teleological theorist
and those who want to supplement (C) in other ways need to answer. It
will be convenient at this point to deal with these objections.
Doesn't (C) apply only to beliefs of the form: s will bring
about t? For these are the only beliefs which are
directly relevant to the satisfaction of desires, as schema (B) makes clear.
Surely, however, an analysis of truth conditions ought to deal with beliefs of
all forms, and not just with beliefs about me ans to ends.
It is not difficult, however, to see why (C) should be
considered to hold for beliefs of all forms, as well as for means-ends beliefs.
It is true that the relevance of beliefs to actions always depends in the last insta nce on what they imply
about appropriate means. And in this sense it is only means-ends beliefs
that are directly relevant to actions. But, still, such means-end beliefs,
that s will bring about t, will as a rule be inferred
by the agent from various other beliefs. And this then institutes the
requisite general connection between truth and satisfaction. For if those other beliefs are true, and the inferences from them
valid, then the belief that s will bring about t will be true to o, and the
resulting action will succeed. So it is a general principle that
actions based on true beliefs will succeed, and not just a principle about
means-ends beliefs as such.10 Consequently, when we invert
this principle into an analysis of truth conditions -- analysis
(C) -- the analysis promises to apply to beliefs in general, and
not just to beliefs of the means-end form.
In general a number of beliefs will lie behind any given
action. But this means that the truth of any one belief will be
insufficient to guarantee the success of ensuing actions. For desire
satisfaction will only be guaranteed if the other beliefs behind the action are
also true. So strictly analysis (C) ought to be formulated:
The truth condition, for any belief, is that
condition which guarantees that actions bas ed on
that belief will satisfy the desires it is
acting
in concert with, assuming that any other beliefs
it
is also acting in concert with are true as well.
But this then disqualifies (C) as analysis of truth-conditional
representation, for it assumes the notion of truth in explaining it.
It might seem that we could deal with this difficulty by
thinking of analysis (C) as applying specifically to cases where single beliefs
generate actions on their own, without the assistance of other beliefs (cf Mellor, 1988, p 86). Truth conditions could then
be identified as what guarantees satisfaction in such single-belief
cases. B ut the trouble with this is that we
then run into objection (1) again, since the only kind of beliefs that can
generate actions on their own are means-ends beliefs. If we want an
analysis of truth that works for beliefs in general, and not just for
means-ends beliefs, then we need a way of extending (C) beyond single-belief
choices of action.
A better way to deal with the problem is to think of analysis
(C) as being applied simultaneously to all the belief types in an agent's repert oire. That is, we
should think of (C) as fixing the truth conditions for all those beliefs
collectively by, as it were, solving a set of simultaneous equations. The
"equations" are the assumptions that the truth condition of each
belief will g uarantee desire satisfaction, if other
relevant beliefs are true; the overall
"solution" is then a collective assignment of truth conditions which satsifies all those equations.
Another initial worry about (C) might be that it makes truth
too easy. Surely we don't want to count beliefs as true whenever the
actions they prompt have satisfactory results. Can't an action achieve a
desired result by acciden t, even though some of the
beliefs behind it are false (as when they involve some self-correcting
mistake)?
But (C) doesn't in fact rule out this possibility. The
suggestion isn't that it's enough, for the truth of a set of token be liefs, that a particular action, prompted by those
particular tokens, should satisfy desires. Rather (C) specifies a
condition which guarantees, for all tokens of the relevant types, that ensuing
actions will satisfy desires.
In many case an agent will act, not on full beliefs, but on
partial beliefs. In such cases the agent's thinking won't pick out any action
as certain to satisfy desires, but rather selec t the
action that is subjectively most likely to satisfy desires. But then, if
the action does succeed, that won't have been guaranteed by the truth of the
agent's beliefs about the world.
It is an interesting question as to how far the well-foundedness of decisions made under uncertainty depends on
objective features of the world, such as the existence of objective
chances. But we can by-pass this issue here. For, once more, there
is nothing in (C) which rules out the p ossibility of
actions whose success isn't guaranteed by the truth of the beliefs behind
them. The idea behind (C) is rather that we should focus on the kind of
case where success is so guaranteed, and then analyse
truth as what guarantees desire sat sifaction in just
those cases. So uncertain decisions issuing from
partial beliefs are beside the point. To apply (C) to a given
belief, we should stick to cases where that belief is held fully, and figures
in decisions which aren't uncertain: truth is what guarantees
satisfaction in those cases.11
Analysis (C) seems to imply that the virtue of truth is
essentially pragmatic, that the reason for wanting tr uth is always so as to
satisfy desires. But surely truth can be pursued as an end in itself, and
not just because of its pragmatic value. Indeed there are certain questions,
about the farther reaches of the universe, say, or the distant past, where our
interest in having true beliefs can't possibly be practical, since such beliefs
can make no difference to our actions.
But this complaint misses its target. (C) isn't a theory about why we should want truth. It's a
t heory of what truth is: namely, for a belief,
the obtaining of a condition which guarantees that, if an agent were to act on
that belief, the ensuing action would satisfy desires. This doesn't presuppose
that anybody will actually act on the b elief.
Nor does it presuppose that the only reason for wanting the truth in respect of
that belief is to be able to act so as to satsify
desires. To be sure, if you do want to satisfy desires, then (C) does immediately
imply that you have a mo tive for wanting the beliefs
behind it to be true. But that leaves room for other motives for wanting
truth, both in the case of practically significant beliefs and practically
insignificant ones. In particular, it leaves room for truth to be valued
as an end in itself. (Can't we now ask: why should truth be valued
as an end in itself? But I take it to be a virtue of (C) that it allows
this as a significant question.)
It might still seem that there are some b eliefs
that couldn't, even counterfactually, be relevant to an action satisfying a
desire. What about the belief that there are no agents, or the belief
that all my actions are doomed to failure?12
At this point we need to appeal to the compositionality of beliefs. As I
shall explain in section 3.9, we need to recognize that beliefs are made up of
components ("concepts"), the representational significance of which
derives from their systematic contribution to the truth conditi
ons of the beliefs they enter into, that is, from
their systematic contribution to conditions which guarantee that actions based
on those beliefs will satisfy desires. Once we recognize this, then we
can hope to pin down the representational signifi cance of concepts like agent, doomed to failure, and so on,
in terms of their contribution to beliefs which can be relevant to action, and
then use those representational values to build up truth conditions for such
special beliefs as can't be relevant to action.
Analysis (C) applies only to beliefs whose truth is of
potential causal relevance to the success of actions. Perhaps this will enable
it to accommodate beliefs about the natural world. ; But what about
moral, or modal, or mathematical judgements? In
what sense, if any, can the truth of such non-natural judgements
matter to the success of action?
I don't propose to pursue this complex topic at this
point. Whe ther or
not analysis (C) might apply to a given category of judgement
depends on the details of the workings of such judgements,
and such details are matters of active controversy for moral, modal, and
mathematical judgements. I shall offer some fur
ther comments on these issues in chapter 6 below.
In my answer to objection (i) I
appealed to the notion of validity: I argued that analysis (C) could be
ex tended from means-ends beliefs to other beliefs because valid inferences
from true beliefs of any kind will lead to true conclusions about appropriate
means. However, it might be argued that this appeal to validity is illegitimate, on the grounds th at
the notion of valdity presupposes the notion of
truth.
Analysis (C) certainly needs the notion of validity.
Often agents will draw invalid inferences about means (imagine that they have
to decide what to do quickly, or that their situation is very complicated) and
then the truth of the beliefs on which those inferences are based won't
guarantee the success of their actions. So if analysis (C) is to apply
generally, and not just to means-end beliefs, it should strictly be fo rmulated
as:
The truth condition of any belief
is that
condition which guarantees that
actions validly
based on th at belief will satisfy desires.
But this now makes the problem clear: (C) can scarcely be held to constitue an analysis of truth, if it presupposes validity
and validity presupposes truth.
One possible move here might be to deny y that validity does
depend on truth. Thus we might seek some purely syntactic notion of
validity, defined in terms of some specified structure of rules of inference,
rather than the semantic notion of any truth-preserving form of
inference. Ho wever, this syntactic strategy
seems unpromising. For a start, there are technical difficulties about
the completeness of syntactic characterizations of non-first-order
validity. And, in any case, given that syntactic characterizations are alw ays answerable to the
semantic conception of validity (cf Dummett, 1974), even for first-order validity, it is
doubtful that the syntactic strategy will really dispose of the circularity,
rather than just brushing it under the carpet.
To deal with this difficulty, I think it is necessary to
broaden the focus away from analysis (C) itself, and reintroduce teleological
considerations. We need to think of validity as playing a part, alongside
truth and desire satisfaction, in fulfillin g the
biological purposes of the overall human decision-making system.
It is fairly obvious, on reflection, that this decision-making
system needs some mechanism for generating beliefs about means, beliefs that
are directly relevant to ac tions, from the total set
of background beliefs that may bear indirectly on the achievability of
desires. And it will clearly be part of the biological purpose of this
mechanism to produce true beliefs about such means, given that the background bel iefs are true. Of
course this inferential mechanism won't always succeed in fulfilling this purpose:
as I just observed, humans often draw invalid conclusions about which means to
adopt. But that doesn't show that validity isn't the infe
rential mechanism's purpose, any more than heart
failures show that blood circulation isn't the heart's purpose.
As I mentioned earlier (see footnote 5), the biological
purposes of beliefs and desires are interdependent, in the sense that desires
will only fulfil their biological purposes if beliefs
fulfil theirs, and vice versa. We now see that
there is a further interdependency, in that both beliefs and desires will only fulfil their biological purposes if the inferential mechanis m fulfils its purpose too, and vice versa.
There is of course nothing surprising about such interdependencies. They
are a common feature of biological systems. For example, the lungs will
only fulfil their biological purpose, of oxygenat ing the blood, if the
heart fulfils its purpose, of circulating the blood, and vice versa.
It might not be immediately clear how these observations about
biological purposes are supposed to solve the original problem. Don't
they jus t amplify the point that truth, in beliefs, and validity, in
inferences, presuppose each other, thereby blocking any possiblity
of explaining one in terms of the other? But the point of reintroducing
biological considerations is not to deny this int erdependence, but rather to show how we can analyse truth and validity simultaneously.
Suppose we start off not presupposing any representational
terms like "truth" or "validity". We proceed to
describe the workings of the human dec ision-making system. It has various interdependent
components: some states (desires) have the biological purpose of
prompting actions which will produce specific results; others (beliefs)
have the biological purpose of prompting actions which are appropriate to
specific circumstances, and hence the biological purpose of co-varying with
those circumstances; and then there is an (inferential) mechanism whose
purpose is to generate new beliefs out of old ones, under the constraint tha t the circumstances which the latter beliefs are
supposed to co-vary with should be guaranteed by the circumstances the former
beliefs are supposed to co-vary with. And then having done all that,
without using the notions of "truth" and "validity", we can
now account for these notions, by saying that beliefs are true when they fulfil their purpose of co-varying with the relevant
circumstances, and that inferences are valid when they fulfil
their purpose of preserving such truth.
This completes my catalogue of standard objections to the
success-guaranteeing account of truth-conditional content given by (C).
My answer to the last objection returns us to th e point at which we left the overall
argument. For this answer dealt with the difficulty about validity by
locating (C) within the biological analysis of the overall human
decision-making system. But we have already noted, at the end of the se ction before last, a rather more straightforward reason for
making this move. Namely, that (C) on its own simply explains truth, for
beliefs, in terms of satisfaction, for desires, and therefore needs
supplementation by an independent account of des ire satisfaction. My
earlier suggestion was that we should fill this gap too by placing (C) within
the biological context of the overall human decision-making system. For
this move then allows us to view desires as having a biological purpose, namely
to prompt actions which produce specific results, and so enables us to analyse desire satisfaction in terms of this purpose.
A question raised when I made this suggestion was whether this
is the only way to remedy the philosophica l
incompleteness of (C). Couldn't opponents agree with the rest of my
argument, but disagree about the teleology? That is, couldn't they agree
that (C) is only part of the truth about truth, which therefore needs to be
supplemented with some f urther account of desire
satisfaction, but then diverge by offering some different explanation of
satisfaction for desires, which does not appeal to considerations of biological
purpose?
For example, they might try to identify the results which
satisfy desires as those which extinguish those desires (cf
Russell, 1921, ch 3; Whyte,
1991). In general, when some desired result is achieved, then that desire
disappears. So perhaps we can identify which results are the objects of wh ich
desires by reference to which results make those desires go away.
Another alternative would be to appeal to the reinforcement of behaviour (cf Dretske,
1988). Often, when a desire prompts some behaviour
which produces a given re sult, that behaviour is reinforced, in the sense that it is more
likely to be repeated when that desire next arises. So perhaps we can identifie the results which satisfy desires as those
results whose achievement leads to the reinforcement of behav
iour.
One problem facing theories of this kind is that they will
still face the problem about validity raised at the end of the last
section. I dealt with this problem by viewing inferential abilities as
part of the overall biologic al system, and accounting for validity in terms of
the biological purpose of this ability. Accounts which seek to dispense
with considerations of biological purpose obviously cannot offer this
solution. Yet they will still face the problem, fo
r merely adding an independent account of desire satisfaction to (C) will still
leave us with the problem that (C), if it is to work at all, needs implicitly
to presuppose an idea of validity, and hence of truth.13
There are ot
her problems facing the alternative suggestions about desire
satisfaction. Take the "extinction theory" of satisfaction
first. On the face of it, some desires are only fuelled their own
satisfaction (salted peanuts), while others are quenched by their
non-satisfaction (sour grapes). Perhaps an
extinction theory can somehow be elaborated so as to deal with these
prima facie counter-examples. But until this is done, the teleological
theory seems to offer a far more powerful and promising approach to desire
satisfaction.
As to the "reinforcement theory", it seems odd to
view this as a more fundamental account of desire satisfaction than that
provided by the teleological theory. The pheneomenon
at issue is that a given action X prompted by a given desire will tend to be
repeated just in case that action gives rise to a given result G --
which result the reinforcement theory therefore counts as the desire's
satisfaction condition. Now, such reinforcement is certainly a genuine
phenomenon. But consider it from a biological point of view. From
the biological perspective, reinforcement of some means X amounts to an
alternative route to achieving G, alongside the cognitive procedure of noticing
that in general X leads to G and acting on this
belief. That is, natural selection in effect sometimes arranges for us to
acquire a derived desire for X in itself, instead of leaving it to our
cognitive system to choose X on the basis o f our prior desire for G and the
explicit belief that X is an effective means to G.
This suggests, however, that reinforcement is, in evolutionary
terms, a relatively primitive method of generating actions. In section
3.5 above I ha d occasion to observe that we human beings fall short of the
kind of biological "super-rationality" which would always choose
actions on the basis of explicit beliefs about the most effective way to
maximize gene bequests. But at the same time I poi nted
out that we have moved some way in this direction, in that we are capable of
doing things which we do not desire in themselves,
simply because we believe them to be means to things we do desire. To
this extent, then, we are more sophisticated t han
organisms who rely entirely on reinforcement, and whose only way of benefitting from evidence that X is normally followed by G
would be to acquire a derived desire for X.
In view of our greater sophistication in this respect, it would
be surprising if our successes in achieving desires were always followed by the
reinforcement of the means adopted. Given that we humans can select
actions as a result of deliberation as well as conditioning, such automatic
reinforcement would be b oth unnecessary and
potentially disadvantageous. And in fact it doesn't always happen.
Even after much experience of satisfying my desire for chocolate by going to
the corner shop, I do not find that I have any desire to vist
the corner shop a s an end in itself.
This implies that the reinforcement theory cannot suffice as an
account of desire satisfaction. To the extent that some desires can be
satisfied without the means adopted being reinforced, as in this last example , we will be unable to equate the satisfaction conditons of those desires with results which lead to the
reinforcement of means. If we want a theory of satisfaction that works across
the board, we will do better concentrate on those results which desires are
suppose to produce when they combine with beliefs in the deliberate choice of
actions.
In this section I want to focus on the ontological
commitments of the account of representation I have developed so far. (It
will be convenient to concentrate on beliefs, but most of the points which
follow could be applied to desires too.) We can summarize the account of
truth conditional content we have now arrived at a s
follows:
(F) The truth condition, for any belief, is that
condition which guarantees that
actions generated
by that belief will fulfil i ts
biological purpose
of satisfying desires.
Note, however, that this analysis (F) (like (C) before it) refers to "truth
conditions", and implicitly views truth itself as a matter of such
conditions "obta ining".
This creates a prima facie problem. For such talk, if taken at face
value, commits us to dubious entities like propositions, or possible states of
affairs, or sets of possible worlds.
Some philosophers would be untroub
led by commitments to abstract objects like propositions and sets. They
can skip ahead to the next section. But I am unhappy with such
commitments, for reasons to be given in chapter 6 below, and so in this section
I want to try to show that t he reification of truth conditions is not
essential to (F).
My argument so far implies that, for any belief-type in an
individual's repertoire, an instance of the following schema will hold:
(G) actions generated by that belief will fulfil the belief's purpose of satisfying desires if and
only if p
Given this, then one way of understanding analysis (F) is as asserting that
claims of the form (G) specify the truth-conditional contents of beliefs.
That is, analysis (F) c an be understood as asserting
that (G) is an equivalent substitute for:
(H) the belief in question is true if and
only if p.
Note now that neither (G) nor (H) refer to truth
conditions as such. So if the import of analysis (F) is simpl y that (G) is equivalent to (H), then analysis (F)
will be free of any substantial commitment to truth conditions too.
What we want from analysis (F) is a theory of content for
beliefs. That is, we want an analysis which explains wh at it is for a belief to have a truth-conditional
content, and which therefore gives us a recipe for determining the specific
content of any given belief. But we can achieve all this without reifying
truth-conditions as objects which attach to belie fs.
For we can simply understand (F) as saying that claims like (H), about
truth-conditional content, can always be replaced by claims like (G), about
biological purposes. I shall understand (F) in this way from now on.
There is a well-known difficulty facing this kind of
approach. If we take (G) at face value, and in
particular don't read "if and only if" in an inadmissibly intensional way, then we ought to accept such instances as:
th
e belief that snow is white will fulfil its
biological purpose if and only if grass is green.
But this is surely unacceptable, if instances of (G) are supposed to amount
to specifications of truth-conditional contents.&nbs p; For the truth condition of the belief
that snow is white is certainly not that grass is green.14
The trouble here, as students of Donald Davidson's theory of
meaning will know, is that any "standing belief", such as snow is
white, is "always" true, if true at all. So we can get a true
instance of (G) simply by mentioning a true standing belief on the left hand
side and placing any true statement whatsoever on the right.
This is where we need to recogni ze the compositionality of beliefs. Instead of
starting with whole beliefs, and taking analysis (F) to explain truth
conditions by equating them directly with instances of (G), we need to start
with the components of beliefs, such as singular concep
ts, predicate concepts, ways of combining concepts,
and so on, and to focus on the referential values of such components, in the
sense of the contributions that such components make to the biological purposes
of the beliefs they enter into. Analysis (F) can then be viewed as
equating truth conditions with conditions built up from such referential
contributions. So now we will not construct instances of (G) directly,
but only by inference from a set of assumptions about belief components, assum ptions which will specify
what is required for the whole beliefs those components enter into to generate
successful actions. And then, since we will now be building up the
(G)-claim for the belief that snow is white, say, from assumptions about the
systematic contribution that the concepts snow and - is white make to
success-guaranteeing conditions across the board, we can expect to derive:
the belief that snow is
white will fulfil its
biolog ical
purpose if and only if snow is white
as desired, rather than:
the belief that snow is
white will fulfil its biological purpose if and
only if grass is green.15
What now of truth itsel f? Those
who reify truth conditions as possible states of affairs, or sets of possible
worlds, or some such, can simply say that a belief is true just in case its
truth condition obtains (the possible state of affairs is actual, the actual
world is one of the set of possible worlds, . . .) But
those of us who want to avoid reified truth conditions need to proceed more
circumspectly. My current thinking on this knotty issue is that we don't
need anything more to understand truth itself ap art from an ability to generate the appropriate
instance of the schema (H) for any given belief. For, if we are able to
do this, then we will have a recipe which tells us what is required for the
belief that snow is white to be true, namely, that th
is belief is true if and only if snow is white; and
what is required for the belief that grass is green to be true, namely, that
this belief is true if and only if grass is green; and so on, for beliefs
in general. And what more do we ne ed to understand truth, if we have a recipe which tells us
what is required for the truth of any given belief?
This is to argue for a version of the redundancy theory of
truth, according to which nothing more is needed to understand claim s about
the truth of beliefs than to understand that such claims stand or fall with the
claims made by the beliefs themselves. It is important, however, to
distinguish sharply between the redundancy theory of truth, in this sense, and
recent "deflat ionary"
theories of truth.16 The difference is that the redundancy theory
leaves room for a substantial theory of content, a substantial theory of what
determines the truth conditions of beliefs, whereas advocates of the
deflationary theo ry argue
that such substantial accounts of content are both unnecessary and misguided.
This difference between the redundancy and deflationary
theories is best brought out by focusing on the question of how someone might
master the abilit y "to generate appropriate
instances of the schema (H)" -- which
is how I phrased, at the end of the paragraph before last, the requirement
which, according to the redundancy theory of truth, is supposed to render any
further understanding of truth redundant. Deflationalists
argue that it is sufficient to know that the sentence +p+ used to identify the
belief that p on the left hand side of any instance of (H) should be the same
as the sentence +p+ used on the right to specify the requir
ement for that belief's truth; or,
alternatively, for versions of (H) which specify truth conditions for
sentences, that it is sufficient to know that the sentence mentioned on the
left of any instance of (H) should be used on the right to specify t hat
sentence's truth condition. The redundancy theory, by contrast, is
committed to no such "minimalist" account of how to generate
instances of (H); it may for instance be
combined, as I would combine it, with the view that the appropriate wa y to generate instances of (H) is to accept (H)'s
equivalence with (G), and therefore to derive (H)'s instances by determining
the biological purposes of the relevant beliefs.
This shows that the redundancy theory should be viewed, not as
a competitor to the deflationary theory, but as something on which both deflationalists and their opponents can agree. That
is, both sides can agree that nothing more is needed to understand truth itself
than a recipe which will tell you for any be lief (or
sentence) what is required for its truth. Disagreement arises only on the
further issue of what such a recipe need involve. Deflationists think
that we need only require that the same phrase appear on the left and right
hand sides of (H)-claims. Their opponents will contend that we do not
have an adequate recipe for generating (H)-claims until we have a substantial
theory of what determines the truth conditions of beliefs (or sentences).
On this issue there seem s to me little doubt that deflationalists are wrong. The point is clearest for
the analogue of (H) for sentences. The deflationalist
says that you will know how to generate the instances of (H) if you know that
the sentence mentioned on the le ft hand side of any instance should be used on
the right hand side. But of course this only works if the sentence
mentioned is in the language you speak, so that you can use it on the right
hand side. To get a notion of truth that applies to s entences
in general, and not just sentences of your own language, the deflationalist needs to add that you will get an
appropriate instance of (H) if the sentence used on the right hand side
translates the sentence mentioned on the left hand side. H owever, this appeal to translation destroys the deflationalist position. For what is it for one
sentence to translate another, in the relevant sense, except for them to have
the same truth-conditional content? So in order to have an adequate r ecipe for generating (H)-claims, you will need to grasp
what it is for two sentences to have the same truth condition. And it is
hard to see how you can do this without a substantial account of what determines
the truth conditions of sentences.
A similar point applies to the version of (H) for
beliefs. The deflationary strategy works fine for beliefs already
identified in terms of their truth-conditional contents, as beliefs that
p. But for beliefs otherwise identified, in terms of causal relations,
say, then we won't know what to put on the right hand side of the relevant
instance of (H), unless we have a substantial theory of what determines truth
conditions for beliefs in general.
So, while I think th at the
redundancy theory gives the right account of truth, I also think that this
account needs to be located within a substantial theory of content.17 The substantial theory of content I favour is in terms of success conditions and biolo gical purposes.
However, I don't necessarily want to argue that you need to embrace this
specific theory of content to understand the notion of truth. For I
certainly want to leave room for lay people who do not share this philosophical
theory of content to understand truth. My view is that such lay people
have an "everyday" or "folk" theory of content which is
substantial enough to allow a satisfactory recipe for generating instances of
(H), but which is philosophically inferior in vari ous respects to the teleological theory of content. I
shall not pursue this issue here, however, though I shall return to it in
section 3.12 below. For the moment we can simply note that the
teleological theory itself is certainly a substantia
l theory of content, and so a suitable philosophical setting for the redundancy
theory of truth.
One last point about the redundancy theory of
truth. As I have explained it, this theory has the disadvantage
that it does not provide an explicit analysis of the notion of truth. It
tells us that the belief that snow is white is true if and only if snow is
white, and the belief that grass is green is true if and only if grass is
green, . . . But it does not analyse truth as a
property that is common to these and other true beliefs.
If we build up the truth conditions for a given repetoire of beliefs recursively from semantic clauses for
the components of those beliefs, then Tarski showed
us how to construct a predicate which applies to all and only the truths among
those beliefs. This construction, however, makes essential use of set
theory. Moreover, it only gives us a predicate equivalent to truth-in-R
(where R is the relevant repetoire of beli efs), not a predicate
equivalent to truth for beliefs in general. The latter problem can
perhaps be solved by equating truth, not with truth-in-any-particular-R, but
rather with the second-order property of satisfying-the-correct-Tarski-definition-o f-truth-in-R-for-the-R-you-belong-to.18 There remains the commitment to set theory.
Perhaps there is some way of finessing this problem too. But, rather than
digressing further down this by-way, let me simply observe that thos e, like myself, who want to avoid commitment to sets,
have the option of abandoning the quest for an analysis of a property common to
all true beliefs, and simply settling for what the redundancy theory does
undoubtedly give us, namely, knowledge of what is required for any given belief
to be true.19
Let me now return to the issue of broad beliefs, beliefs
that physical identicals can differ in. As I
said at the end of se ction 3.3, the theory of
content developed in this chapter will enable us to understand why some beliefs
are broad in this sense.
The best way to appreciate the issue of broad beliefs is to
return to the contrast I drew between two pictur es of action explanation in section 3.5 above. On the
one hand were "internal" explanations, as in:
(A) 1. X desires that G
2. X
believes that F will bring about G
Therefore,
3. X does F
If we focus on explanations of this kind, then it is e asy
to become puzzled about the existence of broad beliefs. For explanations
of form (A) don't require beliefs to do anything except give a causal push to
actions from the inside, as it were. And on this conception of beliefs it
would indeed b e puzzling that differences outside believers' heads can make
any difference to what they believe.
However, as we saw, this isn't the only kind of action
explanation. There are also "external" action explanations,
which explain, not just means, but results:
(B) X desires G
X believes, of some behaviour, that it will
produce G
This
belief is true
__________
X achieves G
Once we focus on thi s kind of explanation, the
kind of explanation to which truth-conditional content matters, then the
existence of broad beliefs and desires becomes unsurprising. Explanations
of form (B) show that truth-conditions are nothing to do with internal push es. Rather, they specify the conditions required for
beliefs to satisfy desires. Given this explanatory role, it is easy to
understand why some beliefs should have world-dependent contents. For
such broad contents will be found whenever two physically identical people are
in different contexts in which different conditions are needed to ensure that
some piece of behaviour satisfies their desires.
The point is clearest for explicitly indexical beliefs.
Su ppose Bill and Ben are physically identical, and
that they both have the desire and belief that they express by "I want to
be warm" and by "Running around will make me warm". Then
they are both likely to start performing the same bodily movements, n amely, running around. And to this extent their
beliefs are the same: both beliefs "push from the inside" in
the same way. But note now that the conditions that will satisfy their
respective desires are different: Bill's desire wil
l be satisfied by Bill getting warm, whereas Ben's
desire will be satisfied by Ben getting warm. And because of this the
condition required for Bill's and Ben's actions to succeed will be
different: Bill's action will succeed just in case Bill 's running around
will make Bill warm, whereas the success of Ben's action requires the quite
different condition than Ben's running around will make Ben warm. And
that is why the truth conditions of Bill's and Ben's beliefs are different,
despite t heir physical identity. It is simply due to the fact that
Bill's and Ben's actions have different success conditions.
This kind of explanation of broadness is not restricted to
explicitly indexical beliefs. It will apply whene
ver the satisfaction conditions of the desires of two
physical identicals are different;
for then, as above, the truth conditions of beliefs germane to the
satisfaction of those desires will be different too. Given the
teleological theory of d esire satisfaction, we can
expect this phenomenon to be widespread, even in the absence of explicit indexicality: for the processes which select desires,
in genetic evolution and in individual learning, will often select desires
because of certain e nvironment-dependent effects of
those desires, effects which will not necessarily be present in the different
environments of physically identical doppelgangers. So, for example, our
desire for water has arguably been selected by a process that favo urs actions that lead us to
H2O; by contrast, a being on a planet with XYZ
instead of H2O could not have desires which have been selected in this
way. Again, it is arguable that my desire for the company of certain
people, say, is the result o f learning processes in which those people played
an essential role; again, a being who had never met those people could
not have developed these desires in this way.
An important special case of broad mental states will be those
ac quired in the course of learning a public
language. Here we will find mental states whose biological purpose is in
essential part to enable us to conform to community usage. (Think of a
child being encouraged when it speaks correctly, and disc ouraged
when it makes mistakes.) So, for example, I may acquire a concept of
arthritis, whose biological purpose is to enable me to apply the word
"arthritis" as the rest of my community does. This yields
another kind of reason why the mentals tates of physically identicals may have different contents: for somebody
may be physically identical to me, and yet live in a community in which
"arthritis" is used differently.
3.11
Accidental Replicas
We have just seen how the teleological theory of
representation can help us to understand why supervenience
is violated by broad beliefs and desires. However, the teleological
theory of representation also implies that the supervenience
of the mental on brain physics is violated in a far more radical way, a way
which is widely regarded as constituting a reductio
ad absurdum of the teleological theory.
This more radical violation of supervenience
arises because the teleolog ical
theory makes representational content depend on selectional
history. The content of your beliefs and desires depends, according to
the teleological theory, on what purposes they were selected to fulfil. So it follows that another being co uld be physically identical to you, and yet not share your
representational states, because it did not share a similarly structured selectional history.
Imagine, to make the issue graphic,
that you have a physically identical doppelganger who does not have any selectional history at all, but who simply coagulated out
of passing molecules a few moments ago, in some massive cosmic
coincidence. Then, according to the teleological theory, this
doppelganger will not share any of your con tentful
beliefs and desires, despite sharing your physical make-up, since none of its
brain states have been produced by any selection processes. And this
seems absurd to many philosophers.20
An initial point that might b e made on behalf of the
teleological theory is that a failure of mind-brain supervenience
as such can scarely refute
the teleological theory. After all, the example of broad beliefs and
desires already shows that the possession of contentful
s tates will often require
certain kinds of context and history, as well as certain kinds of brain
states. So why is it at all surprising that your accidental replica
should lack contentful states? Of course, if we
still upheld the philosophical view, which was widespread before the
recognition of broad beliefs, that differences outside the head cannot matter
to mental make-up, then the accidental replica would be a knock-down refutation
of the teleological theory. But, as it is, why not s imply accept that
the accidental replica is another being whose idiosyncratic background gives it
states with different contents to ours?
However, this reply is less than entirely persuasive. The
existence of broad beliefs can be de fended on independent grounds, by appeal
to pre-theoretical intuitions which owe nothing to the teleological theory of
representation. Because of this, the teleological theory is confirmed by
its ability to explain of the existence of broad beliefs. However,
there are no such pre-theoretical intuitions which show that an accidental
replica does not have any contentful states at all;21 indeed, as I said, most philosophers
view this implication as intuitively absurd. So this implicati
on, unlike the existence of broad beliefs, counts against, rather than in favour of, the teleological theory.
Perhaps defenders of the teleological theory can contest the
awkward intuitions about the accidental replica. Intuitions a bout
complicated counterfactual situations are notoriously insecure. Can we be
sure, when we imagine your accidental replica, that we are really imagining a
purely accidental being, rather than one that has somehow been designed, if not
by natural s election, then by some supernatural power (such as an omnipotent
philosopher who is able to create beings as required to illustrate
philosophical points)? If we were imagining such a designed being, then
the intuition that it has contentful states w ould be no problem for the teleological theory, for
designed states have purposes and so teleological contents. Conversely,
if we really are imagining an accidental being, then perhaps we ought therewith
to relax the intuition that it has contentful states,
which would again let the teleological theory off the hook.
I shall not develop this line of argument any further,
however. For, even if we allow that intuition can somehow simultaneously
guarantee both that an imagined bei ng is genuinely accidental and that it has contentful beliefs, there is still a natural way to defend
the teleological theory. A defender of this theory can simply point out
that the theory is intended as a theoretical reduction of the everyday noti on of represenational
content, not as a piece of conceptual analysis. And as such it can be
expected to overturn some of the intuitive judgements
we are inclined to make on the basis of the everyday notion. Consider,
for example, the theoretic al reduction of the everyday notion of a liquid, to
the notion of the state of matter in which the molecules cohere but form no
long-range order. This is clearly not a conceptual analyis
of the everyday concept, since the everyday concept presuppose s nothing about
molecular structure. In consequence, this reduction corrects some of the judgements which flow from the everyday concept, such as
the judgement that glass is not a liquid.
This appeal to the idea of a theoretic al reduction might
strike some readers as an ad hoc response to the problem of the accidental replica.
But this reaction would be unreasonable. For it should have been clear
from the start that, if the teleological theory of representation is acceptable
at all, it must be as a reduction, not a piece of conceptual analysis.
After all, there is clearly nothing about the natural selection of brain states
in the everyday notions of beliefs and desires.
Perhaps the teleologic al theory of
representation will one day become part of our everyday concept of
representation. By way of analogy, consider the aetiological
theory of teleology itself. When, in the nineteenth-century, biologists
first started to understand bi ological functions in
terms of their Darwinian aetiology, this was
inevitably a matter of theoretical reduction, rather than conceptual analysis,
since the requisite Darwinian notions were simply not available to
pre-Darwinian biological thought. Bu t it is arguable that in the
intervening years Darwinian ideas have come to penetrate the concept of
function itself, with the result that, to biologists, function now just
means: effect for which some trait has been naturally selected. (Cf Ne ander, 1991a.)
This process, of new theoretical ideas being absorbed into old
concepts, is a common enough upshot of the general acceptance of a theoretical
reduction. So, as I said, perhaps one day we will all intuitively think
of representation in teleological terms. At which point the accidental
replica will cease to be a problem, for our intuitions will then come to tell
us that its internal states do indeed lack representational contents (provided,
that is, that we succee d in imagining a being who is
genuinely accidental). However, all these conceptual changes will happen,
if at all, only after the teleological theory of representation has won general
acceptance. So for the time being advocates of this theory will do better
to rest their case on the arguments for theoretical reduction.
At this point it might occur to some readers to ask:
what exactly is the case for the theoreti cal
reduction of representation to teleology? Normally theoretical reductions
are supported by empirical evidence. When chemists established that water
was H20, for example, they adduced a body of empirical evidence which showed
that the exten sions of
"water", as used by most people, and "H20", as used by the
chemists, were in close agreement. So, by analogy, the teleological
theory of representation ought also to be supported by empirical evidence, in
particular evidence which shows tha t the
teleological theory's ascriptions of content coincide with those made by
everyday psychology. But where is this evidence? What grounds have
I offered for believing that the everyday desire for r will in fact turn out to
have been selecte d to produce r, rather than s, or
nothing at all, or the everyday belief that p will turn out to have been
selected to be co-present with p, rather than q, or whatever?22
In this respect the teleological theory of
representation is worse of f than those other theories, discussed in 3.8 above,
which agree that truth is the guarantee of desire satisfaction, but then
explain desire satisfaction in terms of extinction of desires or
reinforcement of behaviour. For, whatever other
difficulti es these
theories may face, they can at least make a plausible case that they are part
of everyday thinking about representation.
The teleological theory of representation, by contrast, needs
to be defended as a theoretical reduction, not as a piece of conceptual
analysis. So its defenders need to produce empirical evidence that its
ascriptions of content coincide with those made by everyday psychology.
I think that they can meet this challenge. But first,
before ex plaining the solution,
let me say a bit more about the problem.
Defenders of the teleological theory obviously need to
recognize that everyday thought embodies a working notion of representational
content, which is available prior to any analysis of representation which the
teleological theory may offer. After all, everyday thinkers who are quite
ignorant of the teleological theory are able to ascribe beliefs, desires, and
other contentful states to people, and by and large
they are able to agree with each other in such ascriptions.
I take it that such ascriptions are informed by a body of folk
psychological assumptions. These will include such general principles as
that people act in ways which their beliefs indicate will satisfy their
desires; that the truth conditions of belief are
conditions which actually produce the satisfaction of desires; that the
satisfaction of desires will often, if not always, lead to their extinction,
and to the reinfo rcement
of the behaviour by which they were achieved;
and so on. These general principles will be supplemented by some more
piecemeal truisms, such as that people can normally see what is in front of
them, that they normally mean what they say , that
they can remember what happened yesterday, that they will desire what they previously
desired in similar cicumstances, that they will be
thirsty if they have had nothing to drink for days, and so on.
Together this body of everyday knowledge constitutes an
implicit grasp of representational notions, a grasp that enables everyday
thinkers to ascribe beliefs and desires with specific contents to people.
The teleological theory should be understood as offering a deepening and ref inement of this everyday understanding. It deepens
everyday understanding, as do all all theoretical reductions,
by giving us fuller information about the nature of the reduced phenomenon,
information which takes us beyond the surface features by wh ich the phenomenon is
normally identified, to the underlying features which explain those manifest
appearances. And it refines everyday thinking by adding precision to our
assumptions about representation and the propositional ascriptions they infor m.
Let me say a bit more about the way the teleological theory
refines everyday thinking. It is an implication of the aguments earlier in this chapter that the general
assumptions of everyday psychology do not by themselves yield co mplete determinacy in ascriptions of propositional
attitudes. I pointed out in section 3.6 that the assumption that truth
guarantees satisfaction places a joint constraint on ascriptions of truth and
satisfaction conditions, but that, without some f urther
account of desire satisfaction, this constraint can be satisfied by deviant
permutations of normal ascriptions of truth and satisfaction conditions.
And I argued that the everyday idea that satisfaction extinguishes desires, or
the idea that it reinforces the means which achieved them, are not adequate to
fill this gap, since they fail to apply to desires in general. In
practice everyday thought no doubt fills much of this gap by appeal to such
piecemeal rules as that people will desire what they previously desired, that
they will be thirsty if they have had nothing to drink for days, and so on. But
we can expect that, even so, there will be certain cases where everyday
thinking is unable to decide about the content of certain desires, nor,
therefore, of the beliefs which inform their pursuit. And in these cases the
teleological theory of representation will be able to make determinate what
everyday thinking does not. Imagine, for instance, a woman who has a recurring
desire which leads her to visit a certain spot in a park. She is not sure
why she does this; it could be for the flowers,
or the restful atmosphere, or various other reasons. There might be
nothing in everyday psychology to determine the conte
nt of her desire. But
there will still be a fact of the matter as to which previous effect of this
desire has led its being preserved, and the teleological theory will fix on this
on the content of the desire.
This would be a case w here the teleological theory fills a gap
left by everyday thinking. There is also the more extreme possibility
that the teleological theory may actively overturn ascriptions of content made
by everyday psychology. The accidental replica discus sed
in the last section is one example of this. And we can imagine other,
more mundane, cases in which everyday psychology's ascriptions of content do
not tally with the selectional history of the relevant
states, and so are deemed wrong by the tele ological theory. However, to return to the main issue
to be addressed in this section, cases like this had better be the exception
rather than the rule. For, before the teleological theory can start
overturning everyday judgements, we need som e evidence that it is an acceptable theoretical
reduction in the first place, and this requires, as pointed out earlier, reason
to suppose that the teleological theory agrees, if not in every case, at least
in most of the prior ascriptions of propositiona l
content made by everday psychology.
The complaint made at the beginning of this section was that as
yet we seem to have no evidence for such agreement. Let me now face up to
this challenge. My strategy here will be to appeal to the argument of
chapter 2 to provide the requisite evidence. In that chapter I argued
that it would be incredible that special-scientific properties should be
variably realized, unless their instances are the product of some selection
mechanism. I think that this line of argument will serve to answer
our present difficulty. For it implies that it would be incredible that
human beings should conform to the assumptions made by everyday psychology,
unless their beliefs and desires had b een selected
by processes which give them purposes corresponding to their contents.
Before going into details, it is probably worth clarifying the
sense in which this argument provides empirical evidence for the coextensionality of the te leological theory's and
everyday psychology's ascriptions of content. This relates to the point,
originally made in section 2.2, that the "incredibility" of variably
realized special-scientific laws without a teleological underpinning is an empirica l matter: the objection to such laws is not
just that they offend brute intuition, but, more importantly, that they run
counter to the wealth of experience which testifies to the general principle
that uniform physical patterns have uniform physical explanations.
To see how these considerations help with the particular
problem at hand, recall generalization (E):
(E) Actions based on true beliefs will satisfy the
desires they are aimed at.
Now consider an instance involving a desire for some specific physical result,
r, like getting hold of an ice-cream:
(I) Agents who act on true beliefs and the
desire fo r ice-cream will get some ice-cream.
Note that (I) specifies a uniform physical state in
the consequent. Yet the antecedent conditions --
desiring ice-cream, and being a true-believer -- are presumably not themselves
uniformly physically realize d. So we might well ask, "Why do these
all physically different antecedents have a uniform physical effect?"
This was just the kind of question we asked in chapter 2.
And the answer we gave there was that in such cases there w ill always be a
selection mechanism which selected the physically disparate instances of the
antecedent because they produce the common effect. In fact chapter 2 has
already applied this analysis to the specific issue of variably realized
desires fo r ice-cream, and
argued that the reason the different physical realizations of the desire for
ice-cream all lead to the ingestion of ice cream is that this is why they were
selected in the first place.
This observation now provides an ans wer to the question of why we should expect the
teleological theory to agree with everyday psychology in ascriptions of
content, at least in respect of desires. The answer is simply that it
would be a mystery that the desire for some physical result r should do what
everyday psychology says it does, as in (I), unless it has been selected to
produce r.23
The corresponding point about true belief is more interesting. Since
generalization (I) generalizes across belief types, not requiring that the
agent have any specific beliefs, but just that the agent's beliefs, whatever
they are, be true, the "true belief" requirement in the antecedent
will be variably realized by the truth of different belief types. Thus, being a
true-believer can be realized by: believing that the shop is open and the shop
being open; or believing that there is ice-cream in the shop and ice-cream
being in the shop; or believing that an ice-cream is within reach and an
ice-cream being within reach; and so on. In different cases, different external
conditions are required for an agent to be a true-believer, and so for the
agent's behaviour to lead to the desired result. And
so now we have this version of the variable realizability
puzzle: why do all the quite different conditions required for different
beliefs to be true all lead, when conjoined with the
possession of those beliefs, to the desired result?
And the solution, once more, is that a mechanism has selected those
conjunctions of condition and belief precisely because they produce such
results. To be more accurate, we should think of the relevant mechanisms as
selecting dispositions to form-certain-beliefs-when24-certain-circumstances-
obtain: for instance, the disposition to
form-the-belief-that-an-ice-cream-is-within-reach-when-an-ice-cream-is-within-reach.
And the reason why different exercises of these disparate dispositions on
different occasions will nevertheless all p roduce
the same result, as required by (I), is that these dispositions will have been
selected precisely because of the kind of effect the relevant beliefs have when
their associated circumstances obtain. It's the conjunction of beliefs
and their tr uth conditions that ensures success, and so it's dispositions
to form beliefs in conjunction with their truth conditions that is selected.
And this now show us how to answer the challenge of this
section in connection with belief contents ,
analogously to the way we answered it for desires. The teleological
theory must match everyday psychology on ascriptions of belief contents
because, as before, it would be a mystery that beliefs that p should do what
everyday psychology says they do, as in (I), unless they had been selected to
be present when condition p obtains.
Perhaps we could have reached this conclusion by a shorter, if
less illuminating, route. In the course of this chapter we have had
occasion to note that our actions are directed by two kinds of mental states,
beliefs and desires: desires have ends attached, and vary over time in
ways attuned to our needs, while beliefs tend to "track" specific
external conditions; and these beliefs and
desires then combine to cause behaviour which causes
those ends if those co nditions do obtain. Now,
this carefully orchestrated arrangement could scarcely have arisen by
chance. If this is really how our psychology works, then surely it must
have been designed for that purpose -- not by a conscious design er, of course, but by the blind selection mechanisms of
learning and evolution. (Cf Millikan, 1989a, pp 292-4.) So once more we
have prior reason to think that beliefs a nd desires must have been selected for purposes
corresponding to their contents, as the teleological theory of representation
claims.
There is an important general moral to be drawn from the
argument o f this chapter, a moral which will be central to the epistemological
arguments in the third part of this book. Namely, that the teleological
theory is radically at variance with verificationist
analyses of meaning which imply a conceptual tie betwee
n the truth conditions of judgements and the
conditions under which those judgements are
asserted. For there is nothing in the teleological theory of
representation, when properly understood, to imply that there should be any
definite correlation be tween
the circumstances in which we are inclined to form beliefs, and those in which
those beliefs are true. The reason is that truth-conditional content, for
the teleological theory, hinges on the results of beliefs, not their
causes. In part icular, the teleological theory
identifies truth conditions as those circumstances in which the actions
prompted by a belief cause the satisfaction of desires. These are not the
same circumstances as those which lead us to adopt the belief. An d there is nothing in the teleological theory to imply
any special link between these two sets of circumstances.
It is true, of course, that there will generally have been some
biological pressure in favour of belief-forming
processes whi ch tend to
yield true beliefs, since true beliefs ensure the satisfaction of desires, and
in general the satisfaction of desires is biologically advantageous. But
this link is easily disrupted. Most obviously, there is the point that
our natur al inclinations to form beliefs will have
been fostered by a limited range of environments, with the result that, if we
move to new environments, those inclinations may tend systematically to give us
false beliefs. To take a simple example, humans a re
notoriously inefficent at judging sizes underwater.
Rather more interesting are cases where our systematic tendencies to false
belief are themselves the upshot of biological design, rather than simply the
result of changed environments . One
illustration of this possibility is the belief about immunity to injury
discussed in section 3.4. In cases of this kind the normal biological
pressure in favour of true beliefs is counterbalanced
by a contrary biological pressure, which encourages us to form the belief about
immunity even when it is false, so as to get us to fight and win. And
there are many other similar25 cases in which biological pressures
produce systematic inclinations towards false beliefs. These fa lse beliefs then lead us to
act in ways that frustrate our desires, but tend to further our biological
needs. And in consequence the circumstances in which we form such beliefs
will be systematically different from those which make them true, for tr uth
conditions are tied to the satisfaction of desires, rather than biological
needs.
Verificationists might feel inclined
to respond that these observations are beside the point,
on the grounds that verificationism only asserts a
tie bet ween truth and normative assertion
conditions, not actual ones. What matters is when people ought to assert
claims, not when they do. So biological demonstrations
that people often do assert false claims are beside the point.
(After all, verificationists can point out, a
distinction between "canonical" assertion conditions and actual
practice has always been implicit in verificationist
thinking, for without some such distinction verificationism
will fail to leave any room for false judge ments.)
However, I don't think that an appeal to this kind of distinction can save verificationism from the biological facts. For once
we allow the kind of radical gap between truth and assertion that is implied by
biology, then ver ificationists face the problem of providing some
independent grounding for assertoric norms. It
is one thing to allow, say, that individual assertoric
practice sometimes falls out of step with the majority line. For then the
majority will prov ide the
norm for individual practice. But if verificationism
accepts that there can be judgements which nearly
everybody gets wrong nearly all the time, then what basis is left for the
thought that nevertheless there are agreed standards of correct judgement which are conceptually tied to the truth?26
Of course, there is one way of construing "assertoric
norms" which will create a conceptual link between truth and normative
conformity -- namely, we can equate such norms with whi
chever judgemental
procedures will lead us to the truth, and then giving some independent analysis
of truth. This is how I myself think of assertoric
norms, with the independent analysis of truth being provided by the
teleological theory of represen tation.
But this is not verificationism.
Verificationism aims to proceed in the opposite
direction, by given some self-standing account of assertoric
norms, and then defining truth in terms of the satisfaction of such
norms. T he normal basis for such a verificationist
account of norms is the actual assertoric practice of
the community. My point is that this route ceases to be available once verificationism concedes to the teleological theory that
the whole community can usually be wrong.
1. I am interested in representation as a problem for physicalism. It is worth observing, however, that the
problem is scarcely peculiar to physicalism.
Even dualists, for example, have an obligation to e xplain
how their special mind-stuff can stand for other things. Not that they
have always recognized this problem, no doubt because their mind-stuff had so
many special powers anyway -- such as the ability to exist outside
space but in t ime, to be transparent to itself, and
so on -- that one more special power scarcely seemed worth worrying
about.
2. Cf Fodor (1990, pp 63 ff).
3. Versions of this teleological approach to mental representation are found
in D ennett (1969, ch 9;
1987, ch 8), Fodor (1984), Millikan
(1984, 1986, 1989a), Papineau (1984, 1986b, 1987), McGinn (1989, ch 2). Fodor
has since recanted. He now holds (1990, Ch 3) that the teleological
approach fails to solve the disjunction p roblem.
He says that there is nothing in teleology to tell us that a frog's fly
detector, say, represents flies rather than
flies-or-any-other-small-black-moving-objects, since a properly working
detector will respond to any small black moving thing .
But Fodor is here assuming that the purpose of the fly detector is fixed by
what causes it, rather than by what it is supposed to cause. However, as
I shall stress in what follows, biological purposes
are always a matter of results. In particular, the purposes of beliefs
are to get the organism to behave in a way appropriate to certain
circumstances. This is why the frog's detector registers flies: the
frog's states cause the frog to behave in a way appropriate to flies, an d not just to any small black inedible dots. (Why flies, rather than food, or survival, or gene perpetuation?
This is a different question, about a "vertical" indeterminacy which
is orthogonal to the "horizontal" indeterminacy of the disjuncti on problem. I shall answer it in footnote
8.)
4. This arguably oversimplifies the example somewhat (cf
footnote 25 below). But for the time being it will be helpful to
sacrifice biological realism to explanatory convenience.
5. While t his gives us one sense in which desire satisfaction is prior,
there are other senses in which the representational powers of beliefs and
desires are mutually dependent. The sense in which desire satisfaction
comes first is this: the biological aim of desires is not (except in
special cases) to produce true beliefs, but the biological aim of beliefs is standardly to satisy
desires. However, this is consistent with the point that desires always
act in concert with beliefs when prompting ac tions,
just as much as vice versa, and therefore that any desire fulfilling its
biological purpose will depend on beliefs fulfilling their biological purposes
too. Moreover, because of this, we can expect desires and beliefs also to
be psychodevelop mentally interdependent, each
category becoming differentiated as a distinct psychological state only when
the other is.
6. Ruth Millikan (1984, 1989b) uses the phrase
"proper function" for those effects of biological traits which they
have been selec ted to
produce (that is, for the aetiological notion of
"function" or "purpose"). It is perhaps worth
observing that in this sense both the "normal" and
"special" purposes of beliefs are "proper functions".
7. Dennett himself favours a selection ist account of representational
content (1969, 1987). However, he seems not to have noticed the tension
between this and his non-realism about beliefs and desires.
8. These points about our human structure of beliefs and desires now answers
the question raised at the end of footnote 2, and explains why our different
desires have different satisfaction conditions, rather than all being aimed
alike at the ultimate evolutionary end of gene perpetuation. For while it
is true that the biologica l purpose of all desires
is in the end to foster gene bequests, different desires have been designed to
foster this end in determinately different ways. This shows up in the
fact that the desire for chocolate, say, doesn't disappear when you accept that
eating more chocolate won't help you pass on your genes. The appropriate
way to think of the purpose peculiar to a given desire is as that result the
desire will lead us to pursue whether or not we believe that result is a means
to futher ends. For further discussion of
this point, see Papineau (1987, sect 4.3).
9. Dennett's non-realism about belief-desire psychology makes him think that
it is absurd to suppose that empirical discoveries might show that we don't
have beliefs and desir es
(1987, p 233-235). I agree that this is absurd. But this is not
because I agree with Dennett that belief-desire psychology is non-theoretical
and so somehow insulated from empirical evidence. Rather, I think it is
theoretical, but alr eady
established by a wealth of evidence.
10. I owe the argument for this principle to Horwich
(1990).
11. This response to the objection about uncertainty was suggested to me by
Hugh Mellor.
12. These examples were put to me by David Owens an
d David Sanford respectively.
13. Whyte (1990) aims to deal with this problem by
arguing that the causal roles by which we ordinarily identify beliefs, and
which then fix their success conditions, happen specifically to involve valid
rather than inval id inferential moves. I agree
that common sense psychology regards the valid implications of beliefs as
constitutive of those beliefs, by contrast with any characteristic tendencies
to generate invalid conclusions. But I think this is because ordinary
thought identifies beliefs by their truth conditional contents, and then helps
itself to the idea of those consequences which validly follow. This means
that any attempt to reduce truth conditional content cannot appeal to common
sense psyc hology's view
that certain inferential consequences are
constitutive of the identity of beliefs. For these sets of constitutive
consequences cannot be characterized without the notion of semantic validity.
14. Why shouldn't we read the "if and only if" in an intensional way? Well, if we read (G) as saying that
". . . the belief . . . will fulfil its
biological purpose in all possible worlds where p", this will solve the
snow is white/grass is green difficulty, but only at the cost of introducing
possible worlds. It is true that an explicit reference to possible worlds
is only one possible way of analysing ". . . the
belief . . . will necessarily fulfil its biological
purpose if and only if p". In chapter 6, however, I sha ll argue that, whether or not
we adopt the possible worlds analysis of modality, modal judgements
cannot be viewed as legitimate expressions of belief, and so are ineligible for
essential roles in our best theories. So I prefer to solve the snow is
white/grass is green difficulty without using modal notions.
15. Donald Davidson's approach to meaning (1984) can also be viewed as
offering a kind of analysis of truth-conditional
claims like (H) (rephrased to apply to sentences rather than bel iefs), through not a
reductive analysis, as above, but rather an implicit analysis, via an
explanation of how to test an empirical "meaning-theory" which
specifies (H)-claims for all a community's sentences. (For an exposition of
this interpretation of Da vidson,
see Papineau, 1987,
sections 2.4-8). This Davidsonian approach to
truth-conditional content has extra difficulties with the "snow is
white/grass is green" problem, however. For, while the problem can
still be solved, given strong enough requirements about the need for
"meaning-theories" to derive their (H)-claims from separate
assumptions for sub-sentential components, it is unclear how to motivate these
requirements within the Davidsonian programme. From my perspective, th is is not a difficulty.
I take a realistic view of belief components and their referential
contributions to biological purposes. So I don't need any independent
justification of the compositionality requirement, of the kind essayed by Davidsonian theorist s, such as that native speakers, or
perhaps meaning theorists, need to derive their knowledge of an indefinite
number of (H)-claims from a finite amount of sub-sentential information.
From my point of view such doubtful appeals to the preconditions for knowledge
of meaning-theories are irrelevant, since I take the compositionality
requirement to be a direct upshot of the semantic facts, irrespective of whether
or not any native speakers, or meaning theorists, know a theory of those facts.
16. Fo r the redundancy
theory, see Ramsey (1927). Deflationary theories are defended in Quine (1970),
17. From this perspective, the redundancy theory can also be vi ewed as consonant with the idea
that truth involves correspondence with the facts. Those who adopt the
redundancy approach to truth will not, of course, want to explain truth in
terms of possible facts "obtaining". But it seems natural to
say, given the redundancy theory, that when the belief that snow is white is
true, for instance, this is in virtue of the fact that snow is white.
This doesn't explain truth in terms of facts, but rather introduces facts as
what make true beliefs true;& nbsp;
still, when a belief is true, there will be a corresponding fact. There
remain questions about the "thickness" of any such fact; are
there any other reasons, apart from the truth of the corresponding judgement, for recognizing the fact, such as, say, its
causal significance?
18. Since this definition generalizes over Rs, the
"adequacy condition" which provides an "external" test for
the correctness of Tarski-style definitions of truth-in-particular-Rs will become part of the definiti
on of truth-in-general. This is what we should expect: it reflects
the point that you cannot have a general recipe for generating (H)-claims without a substantial theory of what determines the
contents of beliefs.
19. At one time I thought that the we could equate
truth for beliefs in general with the property of "generating actions
which are guaranteed to succeed" (cf 1990, p
30). But I now think that the "guaranteed" here conceals a
reference to a reified truth condition, since wha t
we need, for the truth of any token of a belief type, is not just some actual
fact that will cause the action based on the belief to satisfy desires, but,
more specifically, the obtaining of that possible fact which guarantees success
for all actions ge nerated
by tokens of the belief type. An analogous point would apply if we tried
to equate truth for beliefs with the property of "fulfilling their
biological purposes of satisfying desires"; for
such fulfilment needs to be understood in terms of
the general condition required for the relevant belief type to fulfil its purpose, not just in terms of any accidental
route to desire satisfaction.
20. Cf Cummins (1989, ch 7); Whyte (1993).
The problem of the accidental replica is also dis
cussed by Millikan (1984, p 94). Note that the
accidental replica wouldn't present a problem if we divorced the teleological
theory of representation from the aetiological theory
of teleology. But since I see no virtue in non-aetiological
acco unts of teleology, I
shall not pursue this option further.
21.This is perhaps a bit strong, given that some of
the arguments for broad mental states do arguably have the corollary that your
accidental replica will lack some of your mental states. ; Thus, if the
broadness of your concept of water depends upon which liquid was around when
you learnt this concept, then a being that never learnt anything couldn't share your concept. Still, many other broad attitudes
don't depend on learning in t his way, and so there will be no pre-theoretical
reason to deny them to your accidental replica. And, apart from that,
plenty of your beliefs and desires aren't broad at all, and so intuitions about
broadness will do nothing to explain why your repl
22. I owe this objection to the teleological theory to a conversation with
Andrew Woodfield.
23. So far this only deal with desires for physical
things. But the story can be elaborated to accommodate desires for
non-physical things, provided those non-physical things in turn have physical
effects, by reference to which the desires in question can then be
selected. A similar point applies to beliefs. Beliefs can be
selected to be co-present with non-physical condi tions, provided those conditions have physical effects by
reference to which such co-presence can be selected. The discussion of
hierarchies of selection mechanisms in section 2.8 is relevant here.
24. "When" only makes immediate sense for index ical beliefs. For standing beliefs, we need the
compositionality of beliefs to give it substance. That is, we need to
remember that beliefs are made of components, whose representational
significance depends on their systematic contribution to the truth conditions
of those beliefs, and that what gets selected, in the first instance, are
therefore dispositions to deploy such components in just those cases when their
contribution to the truth condition of the resulting belief will be satsified.
25. In fact the earlier description of the immunity-from-injury case was
something of an oversimplification. The real biological problem in such
cases is not that there is no psychological desire corresponding to the
relevant biological need (to fight and triumph), but rather that this desire is
insufficiently strong in comparison with other conflicting desires (like
wanting to avoid injury). Our biology then compensates by favouring beliefs that will get us to pursue such
insufficiently st rong
desires, even on scanty evidence. (Perhaps the best-known of the many
other examples of this structure is the human readiness to conclude that given
foods are poisonous, thereby compensating for our biologically inappropriate
tendency to let ou r hunger outweigh our fear of
poisoning.)
26. Followers of Michael Dummett might feel
inclined to argue that there must be such standards, in order for people to be
able to acquire or manifest their grasp of judgements.
(Cf Dummett, 1976, p 101. ) But the thesis that acquisition and manifestation
depend on agreed standards of correct judgement is
itself undermined by the observation that there are judgements
which everybody tends to get wrong.