Professor John Vervaeke
Functionalism
stands at the end of a long list of theories.
This is true for two reasons: first, it has had many predecessors, it is
fairly new, and the product of many failed theories before it; and second,
there does not seem to be anything following it, waiting to take up the fight,
should it falter like its parents.[1] Its materialist precursors have largely
fallen victim to a tendency to be too chauvinistic, or in any case, too
extreme, in their attempts to subject mental phenomena to analysis into non-mental
terminology.[2] Functionalism, in fact, finds its roots in
an attempt to alleviate this problem by removing the neurological bias, and
thus developing a theory that offers the ability to analytically examine the
mind without a reliance on human-like beings as sole possessors thereof. So it naturally comes as a bit of a painful
surprise, when someone offers an argument that, at least prima facie, would seem to refute functionalist doctrine in one
sweeping motion. Block’s
homunculi-headed simulations are a proposed demonstration that functionalism is
too liberal in its ascriptions of mentality and further, that this liberalism
cannot be adequately fixed within the current theoretical framework – in short,
functionalism is false.
Block’s
argument, as I will show, is rather unfortunately valid – unfortunately, that
is, for proponents of functionalism.
What the argument is not, or perhaps, to be more precise, what the
argument may not be is sound. This paper will concern itself with a
detailed analysis of precisely what it is that Block says in his argument,
followed by a discussion of the possible criticisms thereof (there are
distressingly few) and finally an attack at what appears to be the argument’s
only weak point. My argument, much like
Block’s, cannot claim to have made a wholly compelling case. Whereas I will show that Block’s argument is
basically an argument from inconceivability, my own argument must then, to
adequately counter Block’s, be an argument from conceivability. Neither of these is binding, the argument is
a question of shifting the burden of proof.[3]
Block
is concerned with showing that a functional description of a mind is
insufficient for capturing all of the mind’s qualities. To do this, he proposes
a thought experiment designed to play our intuitions against functionalism, by
realizing a functionalist system in a very bizarre form: China (Block 1975,
276-278). What he proposes we imagine
is that, in the name of philosophical progress, China embarks on an attempt to
realise a human mind by having its citizens play the roles of individual
neurons,[4]
interconnected by radio link. (Block 1975, 276). Oddly enough, this is actually Block’s attempt to propose a more realistic thought experiment,
extending from another experiment of similar intent. It will be useful to
consider the experiment from which the China example arose (although the China
example is perhaps more persuasive) which dealt instead with a single body,
… externally like a human body, say yours, but internally quite different. The neurons from sensory organs are connected to a bank of lights in a hollow cavity in the head. A set of buttons connects to the motor output neurons. Inside the cavity resides a group of little men. Each has a very simple task: to implement a ‘square’ of a reasonably accurate machine table that describes you. (Block 1975, 276)
The idea of both experiments is to provide a correct,
if somewhat bizarre, implementation of a mind, as defined by
functionalists. The idea that the
little men (and by extension, we as well) are guided by a machine table is
taken from Putnam’s definition of functionalist theory, whose first principle
is “All organisms are probabilistic automata”[5]
(Putnam 1967, 227). All Block has done
then, is to extend this principle in some rather unusual ways; the first in the
fantastic notion of a homunculi-headed copy of yourself, and the second, a
homunculi-writ-large version encompassing an entire nation. In both cases, they are doing exactly what
Putnam has deemed they ought to do, they are implementing a machine table which
we assume presents an accurate picture of your mind. According to Functionalism then, argues Block, China and the
homunculi-head both, should be (or have, the distinction is unclear) minds.
This
notion, however, is squared against the common sense intuition we have, that
China[6]
does not have, cannot have, that it is almost nonsensical to discuss the idea
that China has a mind. In Block’s
words,
What makes the
homunculi-headed system (count the two systems as variants of a single system)
just described a prima facie counterexample to (machine) functionalism is that
there is a prima facie doubt whether it has any mental states at all—especially
whether it has what philosophers have variously called ‘qualitative states’,
‘raw feels’, or ‘immediate phenomenological qualities. (1976, 278).
What we have then, in essence, is an argument against
functionalism by Modus Tollens:
·
If machine functionalism as Putnam describes it is
true then China has a mind.
·
However, by intuition, China does not have a mind.
\ Machine
functionalism as Putnam defines it is false.
This reduction to a basic
logical truth adds a great deal of strength to Block’s argument, or rather,
makes clear just how powerful Block’s argument is. The fundamental structure is logically valid, unlike so many
philosophical arguments which, in the end, reduce themselves to an inductive appeal
at best. Now, in truth, this is not a
perfect modus tollens, because Block freely admits that the second premise,
that China does not have a mind, seems self-evident, but is not certain. In fact, he points out that “Appeal to
intuitions when judging possession of mentality…is especially suspicious” (Block 1976, 281). Thus the argument remains logically valid, but rests on the assumption
that our intuitions hold.
Having
outlined the argument in what I think is a fair and accurate way, I will
examine some potential criticisms of Block, and why I believe they fail. While it is my eventual goal to present an
argument against Block, it is equally important to establish what my argument
is not, to spare some objections that
might otherwise be made. The analysis
will also demonstrate again that Block’s argument is really quite strong, for
the most part.
The
first, instinctive method of defense is to deny Block’s claim that China
satisfies the functionalist criteria of mind.
To me, this seems contradictory, but a functionalist might be disposed
to do so, when confronted with the fact that her philosophy licenses such a
conclusion. The only avenue I can see from
which to launch such an attack would be in the idea that somehow, the argument
was a poor analogy, but I don’t think that such an argument can run. Block’s argument is not, in truth, an
argument from analogy at all. He is not
saying that China is like a computer,
or other more common functionalist tools, he’s saying that China, by Putnam’s own
criteria, is a satisfactory
realization. The idea that functionalism implies a machine-table theory of mind
realizable in any properly designed physical
system is Putnam’s, not Block’s, and any attempt to attack the argument from
this direction would be to attack one’s own theory.
A
second, more appealing defense might be to suggest that the argument simply
points out a failure of current functionalist theory, and that a modification
of the theory would save us from Block’s conclusion. What the nature of this modification could be, I am not sure, but
it doesn’t seem to matter—Block has already answered this approach quite
effectively, in addressing the chauvinism/liberalism distinction (1976,
291-293). What Block argues is that, as functionalism now stands, it is
“hopelessly liberal” (1976, 292), and further, that any attempts to tighten
functionalist theory, through restricting the systems classified as minds,
leads immediately to human chauvinism.
This is the source of his Functionalism/Psychofunctionalism
distinction. In contrast to the
traditional functionalists, which allow a large variety of systems into the category
of mental systems, Psychofunctionalism would be a doctrine that restricted
entry to only those systems that shared a psychology with us. This might rescue functionalism from some
arguments, but Block goes on to point out that this eliminates the possibility
of other minds, equally possessed of mentality, but opposite in psychological
makeup (1976, 291-292). At the risk of
getting sidetracked, I will leave this argument where it stands, but suffice it
to say that this too is not my objection – I do not see that functionalism can
be successfully mended in this way.
So
what then, is my argument against Block?
An examination of the previous two arguments is illuminating – both
proceeded from the basic notion that Block was correct in assuming that China
did not have mind. They were arguments
framed as attempts to save functionalism from the seemingly contradictory
conclusion that China did have mentality.
Going back to my analysis of Block’s argument structure, then, they were
attempts to falsify the first premise.
I have already indicated my own opinion though, which is that this first
premise is sound. My task then, is to
examine the second premise, in hopes of weakening it sufficiently that Block’s
argument becomes questionable, at best.
At this point, we must return to the idea of inconceivability arguments,
why this is such an argument, and what can be said about such arguments in
general.
To
see that this is a conceivability argument is not difficult, Block himself
points this out frequently in the argument, but uses the phrase prima facie instead. Essentially, the argument rests on the appeal
to the reader’s intuition that China cannot in fact have mental states,
especially not qualia (Block 1976, 278,280).
In attempting to strengthen this appeal to intuition, Block notes the more
general principle that without sufficient justification, there is good
intuitive evidence against any mechanism
possessing qualia,
No physical mechanism seems very intuitively plausible
as a seat of qualia, least of all a brain. Is a hunk of quivering gray stuff more
intuitively appropriate as a seat of qualia than a covey of little men? If not, perhaps there is a prima facie doubt
about the qualities of brains systems too?
However, there is a very important difference between
brain-headed and homunculi-headed systems… we
are brain-headed systems, and we
have qualia. (Block 1976, 281)
While he is right, in the sense that our experience of
qualia helps to reduce doubts we might otherwise have about our own mentality,
the statement ends there in its utility.
It does not give us any more reason to believe his argument, if
anything, it just peremptorily answers a potential objection that may have been
raised. Still, in shifting the issue to
one of allaying doubt, an important fact is brought to light. Block’s argument is critically dependant on
doubt. That is, we have no solid reason
to suspect that China has qualia, and so in the absence of such a reason, we
doubt that it does. This doubt is the
nature of the second premise in the argument as outlined above, and it also presents
a possibility to counter the argument. To
do se we must show that there is reason to doubt the doubt, as it were, reason at
least in principle, to accept the possibility that China might experience qualia. If
a good argument can be given for the possibility of China’s having qualia, then
we will have as much reason to accept China’s mentality as we do to accept our
own, and Block’s argument will be significantly weakened, if not overturned. The argument need not be entirely incontrovertible
either[7],
but must simply provide an acceptable reason to suspend judgement about China’s
mentality. To put it into legal jargon
then, it is sufficient to show that there is ‘reasonable doubt’ about the
impossibility of China’s mentality.[8] It shall be my focus in the remainder of
this paper to demonstrate that such reasonable doubt exists.
First
of all, let us establish what exactly we mean when we talk about “having
mentality”. As an earlier quote
demonstrates[9], Block seems
at least partly willing to accept that China would be capable of some mental-like
operations, though not the elusive qualia.
This point is perhaps a fine one, but it limits the scope of Block’s
objection. There is no reason to reject
China as a mind, where mentality consists of calculations, or even linguistic
use, for example. These are things that
can be accomplished by a sufficiently well-designed computer, and China as
Block describes it is indeed a sort of organic computer. This is only to say that Block’s contention
is not, or should not be, that China is capable of none of the things that a mind is, certainly a great deal of mental
function can be accurately implemented by China without conflicting with our
intuitions. The real sticking that
Block perceives in Functionalism is the issue of qualia, there does not seem to
be anything that it is like to be
China.[10]
What
is important to note here, is that Block, like the rest of us, are presupposing
a psychological framework, under which we do our philosophy. An admittedly difficult thing to overcome, we
are restricted by our conception of qualia – our conception of mind – to considering only minds like
our own. What we are saying, when we
say that we cannot conceive of China having a mind, is exactly that – we cannot conceive it. Our folk-psychological theories of mind
extend only to minds that in some very important ways, are identical to our
own, and it must be acknowledged that this may not be an objectively valid premise
from which to reason. Accordingly, any
theory of qualia that was sufficiently divergent from Block’s (or what I will
call the Intuitive theory of Qualia), might be enough to allow such things as
China to have minds after all. Do such
theories exist as a matter of anything but theoretical possibility? Indeed, they do, and I shall attempt to
demonstrate that these theories (there are two I will consider specifically)
are both philosophically strong, and sufficiently divergent from the Intuitive
theory that they cast doubt on Block’s conclusion. Remember that in an argument of burdens of proof, reasonable
doubt is all that is required.
The
first alternate theory I will consider comes from recent writings by Fred
Dretske. In Naturalizing the Mind, Dretske develops an alternative theory of
Qualia that treats Qualia as representational in nature, that is, the subjective
feel of something, the elusive aspect of mentality, can be reduced to talk
about representation.[11]
More precisely, qualia is a sort of metarepresentational effect,[12]
that arises out of the different ways our representational systems are
structured. To illustrate this, Dretske
uses a pair of speedometers,
Imagine two
instruments, J, and K. J is a precision
device manufactured to measure speed in hundredths of miles per hour. When it registers 78.00 that (as the digits
after the decimal suggest) means not 77.99 (and below) and not 78.01 (and
above)… K is a less expensive device, designed to provide rough information
about speeds. Its registration of 78
means not 77 (and below) and not 79 (and above). (Dretske 1997, 75).
Dretske argues that even when travelling at the same
speed, J and K will ‘experience’ different things, because they represent the
information in different ways (see especially Dretske 1997, 75, 78-80). Further, he argues that this is at the root
of all the subjective experience that we encounter. His theory describes qualia as simply a product of each
individual’s unique representational system.
Naturally, this example is simplified, and it is important to note that he
is by no means making the claim that when two people differ, it is because one
is better than the other, only that their representational schemes differ in
some measurable, naturalizable way. The implication of such a theory then is
obvious – qualia can be naturalized.
And if qualia can be naturalized, then they can be mechanized, which
means that they no longer present a problem for China, nor any other properly
implemented probabilistic automaton. While a full treatment of his theory is
beyond the scope of this paper, it is clear that Dretske presents a coherent prima facie alternative to the Intuitive
theory.
A
second escape from the Intuitive theory lies in its potential to contradict
itself. This argument is not so much an
alternative to the Intuitive theory, but more a good reason why we should
consider rejecting it, even if there were no acceptable alternative. Stated simply, the objection is:
·
If qualia cannot be captured by a probabilistic
automaton, it is because they play no role in that which a probabilistic
automaton considers, i.e.: they do not result in behaviour, or a change in
state – they are not mentally causal.
·
But if they are not causal, they cannot cause
memories, nor learning, nor any other mental phenomena.[13]
·
And yet we retain sufficient memory of qualia that we
can describe them (however awkwardly) and even develop philosophical theories
about their natures, therefore they must be causal in some way.
·
Thus, by another application of modus tollens, the claim
that qualia cannot be represented in a probabilistic automaton must be false.[14]
This objection is not an easy one for Block to
circumvent if he wishes to maintain his rejection of functionalism. He cannot challenge the first claim - that by
giving up its place in the probabilistic automaton, qualia gives up mental
causality - without inventing some new form of causality not expressed by said
automata. If he accepts their lack of
causal role, then the second claim is a logical necessity. Finally, to reject the third premise, to
state that we do not in fact have a memory of qualia per se would be to give up entirely, since his objection rests on
qualia being very real. It is possible
that with sufficient argumentation, Block could develop a defense to this
argument, but remember that all we require is prima facie doubt. Clearly, if his assumptions lead as quickly
to contradiction as those he presumes to dismiss, there is reason to doubt his
conclusions.
Block
is correct in saying that conceivability arguments should always be regarded
with a great deal of skepticism. The
danger of appealing to our intuitions is that if they were all we relied upon,
we could never develop the truly counterintuitive theories that are frequently quite
valuable, if not true. There is every
reason to suspect that if China did
have mentality, it would be of such a vastly different nature that it is
doubtful we would ever comprehend it, let alone intuitively predict it. Contrariwise it could have mentality just like
our own, perhaps mind is consistent over vast differences of scale and implementation. More importantly though, this paper is not
about proving that China has mentality at all, it is simply about establishing
reasonable doubt. Block’s argument is
predicated on the assumption that what functionalism predicts about China is false,
but he has only burden-of-proof arguments upon which to base that
conclusion. Through analysis of the
argument, and consideration of some persuasive alternatives, it becomes clear
that there is at least as much argument for China’s mentality as there is
against it. Functionalism, in other
words, is not refuted by Block’s argument.
But as I stated at the beginning of this paper, all I can do is shift
the burden of proof back on to his shoulders – there may be other good reasons
why functionalism fails. The China
argument is simply not one of them.
Works Referenced
Block, Ned.
‘Troubles with Functionalism’, in Block, 1980. pp. 268-305. 1975.
Block, Ned, ed. Readings in the Philosophy
of Psychology, vol. 1. Cambridge,
MA: Harvard University Press, 1980.
Dretske, Fred.
Naturalizing the Mind.
Cambridge, MA: MIT Press, 1997.
Nagel, Thomas.
‘What is it like to be a bat?’ Philosophical Review. 4 (1974).
pp. 435-450.
Putnam, Hilary. ‘The Nature of Mental States’, in Block, 1980. pp. 223-231. 1967.
Putnam, Hilary. ‘The Mental Life of Some Machines’, in Intentionality, Minds, and Perception, ed. Hector-Neri Castañeda,
Detroit, 1967, pp. 177-200. 1967a.
Shoemaker, Sydney. ‘Functionalism and Qualia’, in Block 1980. pp. 251-267. 1975
Shoemaker, Sydney. ‘Absent Qualia are Impossible’, Philosophical Review. vol. 90(4).
pp. 581-599
[1] Of course, I do not mean to imply by this that functionalism is the only available theory of mind. Rather, that in the traditional program of philosophy of mind, (that is, to the exclusion of recent connectionist and dynamical systems models) there are few other materialist philosophies with the strength that functionalism possesses.
[2] Consider the original type-identity theorist as an example of the former, and Churchland’s eliminativism for the latter.
[3] Or perhaps, to borrow Block’s terminology, the argument between establishing a prima facie case for, and a prima facie case against.
[4] Or better, functional units.
[5] For an explanation as to how Turing machine tables can be extended to become probabilistic, see Putnam 1967a.
[6] From this point on, I will assume that all arguments apply equally well to both thought experiments since one is just the other writ large, they are functionally equivalent.
[7] As Block is no doubt aware, a truly compelling, objective reason to accept our own qualia as valid is exceedingly difficult - hence his appeal to the rather elusive Anthropic Principle.
[8] Or, to untangle the double negative, that there is reason to accept the possibility of China’s mentality.
[9] (Block 1976, 278)
[10] Block’s reference, and my own, are to Nagel, 1974.
[11] Admittedly, this brings along its own set of problems, the mechanics of representation is not a topic that has been solved, by any stretch of the imagination. Naturally, a proper treatment of the debate is beyond the scope of this paper, but is also unnecessary, as we need only demonstrate prima facie that adequate alternative theories exist.
[12] This is my terminology, not his, to the best of my knowledge.
[13] This is clearly an argument similar to that levelled against epiphenomenalism.
[14] I arrived at this argument independently, although a similar argument has been made in Shoemaker 1975 and again in Shoemaker 1981.