Tuesday, September 6, 2011

Quote of the Day

The first move: materialism as scientific hypothesis
U. T. Place argued that it is tenable to say that certain events and processes traditionally classified as mental (for example, sensation) are identical with events and processes in the brain. That this is indeed so he labelled as materialism, and argued that it is in fact a scientific hypothesis. In response to Smart he agreed further that the conditions required for the assertability of such a hypothesis -- conditions under which alone such an identity statement can be true -- are subject to philosophical debate rather than empirical testing. But once such conditions are specified, the remaining question is empirical. For the described 'mental' events and processes have a certain complexity, which brain events and processes may or may not have. The name "materialism" is also given to this or closely similar claims about the psychological e.g. by David Armstrong.

There are three preliminary questions to be raised. First of all, not every replacement for what I have called the Thesis can be accepted as the 'real' materialism -- can this one? Since the main question before us is what exactly the materialist's main thesis could be, we should perhaps accept any seriously offered contender. But if we could identify certain familiar psychological events and processes with physiological ones in some not too weak sense, we would hardly be finished with the traditional concerns of materialism. That a person has a purpose, for example, does not consist in any specific type of occurrent event or process; nor that her sins are forgiven, that she is in a state of grace, or that she is precious beyond rubies. And these are only examples about persons; what else may there not be between heaven and earth never dreamt of in materialist philosophy? I don't want to be fanciful, but merely establishing that sensations are brainstates seems hardly more than a drop in the bucket for the materialist. The virtue of such a ringing Thesis as "Matter is All" was to settle the hash of all such stuff once and for all.

Second preliminary question: does the description of the 'mental' or the psychological in terms of which the replacement thesis is formulated, do justice to its intended concern? Armstrong was rather more conscious than Place of the second preliminary question when he was debating Malcolm, a Wittgensteinian. Today he would also have to contend with putative failures of functionalism, arguments that no computational theory of consciousness could even in principle be successful, and demonstrations that truth conditions for belief attributions must have historical and social parameters outside the believer.

But leave these debates aside. Third question: supposing the empirical claim is false, or is scientifically investigated and found wanting, will there or will there not be a fall-back position to call 'the real materialism after all'? It would be a poor game if after much scientific strife, the loser could say "that's not it at all, that is not what I meant at all." Well, what if we accept Place's or Armstrong's formulation, and their empirical claims are found wanting? Suppose, for example, that no neurological process can be identified which can even in principle predict human decisions reached simultaneously or at the exact end of that process. The next empirical question would be what probabilities can be assigned to the (neutrally described) actions being decided upon, conditional on the states of the central nervous system. If these probabilities cannot even in principle be made as near zero and one as we like, is that the end of materialism?

Think of the exact parallel: no quantum state will predict the exact time of radio-active decay. Is that the end of materialism? It is not; and neither would materialism come to an end if what humans do could be related only probabilistically to their brainstates. A favorite belief of the materialists would have to be relinquished, but they would all know how to retrench. For the spirit of materialism is never exhausted in piece-meal empirical claims.

The second move: whatever it takes
If you press a materialist, you quickly find that the most important constraint on the meaning of the Thesis is that it should be compatible with science, whatever science comes up with. This is contrary to what some of them say. If, they say, certain phenomena could not be explained purely in terms of material factors, then the scientific thing to do would be to give up materialism. But, holding the Thesis, they make the bold conjecture that this will never happen. That what would never happen?

If that question cannot be answered with a precise and independent account of what material factors are, there is still one option. That is to nail a completeness claim to science, or to a specific science such as physics. The instructive example here is J. J. C. Smart, who begins his essay "Materialism" with an offer to explain what he means:

By 'materialism' I mean the theory that there is nothing in the world over and above those entities which are postulated by physics (or, or course, those entities which will be postulated by future and more adequate physical theories).

He quickly discusses some older and more recent postulations in actual physics, which make that 'theory' look substantive. But of course the parenthetical qualification makes that discussion completely irrelevant!

Smart may believe, or think that he believes, the 'theory' here formulated; but if he does, he certainly does not know what he believes. For of course he has no more idea than you or I of what physics will postulate in the future. It is a truly courageous faith, that believes in an 'I know not what' -- isn't it?

Indeed, in believing this, Smart cannot be certain that he believes anything at all. Suppose science goes on forever, and every theory is eventually succeeded by a better one. That has certainly been the case so far, and always some accepted successor has implied that the previously postulated entities (known, after all, only by description) do not exist. If that is also how it will continue, world without end, then Smart's so-called theory -- as formulated above -- entails that there is nothing. Let's not be too quick to celebrate this demonstration of clear empirical content (about what the future of physics will not be like). Most likely Smart did not notice this implication and would have preferred to rephrase if he had.

In a clear indication that he is at least subliminally aware of the problem, Smart quickly adds some extra content. Not content with his initial formulation once he realizes that it is compatible with emergent properties, holism, and the irreducibility of biology to physics, he says

I wish to lay down that it is incompatible with materialism that there should be any irreducibly emergent laws or properties, say in biology or psychology.... I also want to deny any theory of 'emergent properties'.... (ibid. pp. 203-204)

We should read this as an amendment of the above definition of materialism, for the 'theory' formulated above does not fit this bill. We must wonder how Smart knows that it is not adequate. Is he perhaps telling us that either physics will forever eschew emergent properties, or else materialism is false? Since quantum physics provides, at this point, a clear example of holism, should we conclude that materialism has already come to an end?

Of course not. Faced with the consequences of the stance that materialism should be whatever it takes to be a completeness claim for physics, Smart started backpedalling. Everything that is "repugnant" to him (to use his phrase) may be incorporated in future physics. So he adds, in effect, that physics will be false if that happens. But faced with that consequence, no materialist will stick by him if he sticks by that. They'll point out, quite rightly, that he was of a 'classical' mind, and like so often happens with the older generation in physics itself, quite unable to assimilate new visions of the structure of the material world.

Materialism as false consciousness
So is it all just a matter of scientific reactionaries with their self-trivializing theses dressed up as uncompromising metaphysical constraints on science? No, it is not. For all this effort to codify materialism bespeaks something much more important: the spirit of materialism. Materialism is a hardy philosophical tradition, which appears differently substantiated in each philosophical era. Each instantiation has its empirical as well as its non-empirical claims, which interpret for that era, in its own terms, the invariant attitudes and convictions which I call here the 'spirit of materialism'.

How shall we identify what is really involved in materialism? Our great clue is the apparent ability of materialists to revise the content of their main thesis, as science changes. If we took literally the claim of a materialist that his position is simply belief in the claim that all is matter, as currently construed, we would be faced with an insoluble mystery. For how would such a materialist know how to retrench when his favorite scientific hypotheses fail? How did the 18th century materialists know that gravity, or forces in general, were material? How did they know in the 19th century that the electro-magnetic field was material, and persisted in this conviction after the aether had been sent packing?

Of course it is possible to measure certain quantities. But that cannot provide the criterion needed. Just think again of the transition from Cartesian to Newtonian physics. Newton identified forces as the causes of changes in states of motion. Accordingly, if you measure the direction and rate of change of momentum, you obtain a description of that cause in terms of its effects. (The recipe for measuring force direction and magnitude is exactly to measure those effects.) But it could be added consistently that these causes are immaterial, spiritual -- even mental, if Mind does not need to be someone's mind. If instead the forces are said to be material just like the extended bodies so classified before, the materialist must seemingly have some rather mysterious type of knowledge: a knowledge-that the newly introduced entities have the je ne sais quoi which makes for materiality.

But what is it then, in this metaphysical position, that guides the change in content, which it would be pedantic to signal with a change in name? If the "physicalist" or "naturalist" part of this philosophical position is not merely the desire or commitment to have metaphysics guided by physics -- i. e. something that cannot be captured in any thesis or factual belief -- then what is it? This knowledge of how to retrench cannot derive from the substantive belief currently identified as the view that all is physical. So what does it derive from? Whatever the answer is, that, and not the explicit thesis, is the real answer to what materialism is.

Hence I propose the following diagnosis of materialism: it is not identifiable with a theory about what there is, but only with an attitude or cluster of attitudes. These attitudes include strong deference to science in matters of opinion about what there is, and the inclination to accept (approximative) completeness claims for science as actually constituted at any given time. Given this diagnosis, the apparent knowledge of what is and what is not material among newly hypothesized entities is mere appearance. The ability to adjust the content of the thesis that all is matter again and again is then explained instead by a knowing-how to retrench which derives from invariant attitudes. This does not reflect badly on materialism; on the contrary, it gives materialism its due. But it does imply that only the confusion of theses held with attitudes expressed, which yields false consciousness, can account for the conviction that science requires presumptive materialism.

I mean this as a diagnosis of materialism, not a refutation. Its incarnation at any moment will be some position distinguished by certain empirical consequences, and these will either stand or fall as science evolves. But whether they stand or fall, materialism as general philosophical position, as historical tradition in philosophy, will survive. Given this, however, there can -- for that very reason -- be no question of regarding materialism as an assumption at the foundations of science. There is no 'presumptive materialism' which constrains scientific theories to consistency with certain determinate factual theses. For even materialism itself is not so constrained, and it survives by changing so as to accommodate the new sciences.

Bas C. van Fraassen
"Science, Materialism, and False Consciousness"
Warrant in Contemporary Epistemology: Essays in Honor of Plantinga's Theory of Knowledge

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