Posts tagged ‘Newton’

Or perhaps Chomsky’s endorsement of Isaac Newton’s mysterianism.  We tend to think of Newton as bringing physics to a triumphant state of perfection, one that lasted until Einstein, and with qualifications, still stands. Chomsky says that in fact Newton shattered the ambitions of mechanical science, which have never recovered; and in doing so he placed permanent limits on the human mind. He quotes Hume;

While Newton seemed to draw off the veil from some of the mysteries of nature, he shewed at the same time the imperfections of the mechanical philosophy; and thereby restored her ultimate secrets to that obscurity, in which they ever did and ever will remain.

What are they talking about? Above all, the theory of gravity, which relies on the unexplained notion of action at a distance. Contemporary thinkers regarded this as nonsensical, almost logically absurd: how could object A affect object B without contacting it and without and internediating substance? Newton, according to Chomsky, agreed in essence; but defended himself by saying that there was nothing occult in his own work, which stopped short where the funny stuff began.  Newton, you might say, described gravity precisely and provided solid evidence to back up his description; what he didn’t do at all was explain it.

The acceptance of gravity, according to Chomsky, involved a permanent drop in the standard of intelligibility that scientific theories required. This has large implications for the mind it suggests there might be matters beyond our understanding, and provides a particular example. But it may well be that the mind itself is, or involves, similar intractable difficulties.

Chomsky reckons that Darwin reinforced this idea. We are not angels, after all, only apes; all other creatures suffer cognitive limitations; why should we be able to understand everything? In fact our limitations are as important as our abilities in making us what we are; if we were bound by no physical limitations we should become shapeless globs of protoplasm instead of human beings, and the same goes for our minds. Chomsky distinguishes between problems and mysteries. What is forever a mystery to a dog or rat may be a solvable problem for us, but we are bound to have mysteries of our own.

I think some care is needed over the idea of permanent mysteries. We should recognise that in principle there may be several things that look mysterious, notably the following.

  1. Questions that are, as it were, out of scope: not correctly definable as questions at all: these are answerable even by God.
  2. Mysterian mysteries; questions that are not in themselves unanswerable, but which are permanently beyond the human mind.
  3. Questions that are answerable by human beings, but very difficult indeed.
  4. Questions that would be answerable by human beings if we had further information which we (a) either just don’t happen to have, or which (b) we could never have in principle.

I think it’s just an assumption that the problem of mind, and indeed, the problem of gravity, fall into category 2. There has been a bit of movement in recent decades, I think, and the possibility of 3 or 4(a) remains open.

I don’t think the evolutionary argument is decisive either. Implicitly Chomsky assumes an indefinite scale of cognitive abilities matched by an indefinite scale of problems. Creatures that are higher up the first get higher up the second, but there’s always a higher problem.  Maybe, though, there’s a top to the scale of problems? Maybe we are already clever enough in principle to tackle them all.

If this seems optimistic, think of Chomsky the Lizard, millions of years ago. Some organisms, he opines, can stick their noses out of the water. Some can leap out, briefly. Some crawl out on the beach for a while. Amphibians have to go back to reproduce. But all creatures have a limit to how far they can go from the sea. We lizards, we’ve got legs, lungs, and the right kind of eggs; we can go further than any other. That does not mean we can go all over the island. Evolution guarantees that there will always be parts of the island we can’t reach.

Well, depending on the island, there may be inaccessible parts, but that doesn’t mean legs and lungs have inbuilt limits. So just because we are products of evolution, it doesn’t mean there are necessarily questions of type 2 for us.

Chomsky mocks those who claim that the idea of reducing the mind to activity of the brain is new and revolutionary; it has been widely espoused for centuries, he says. He mentions remarks of Locke which I don’t know, but which resemble the famous analogy of Leibniz’s mill.

If we imagine that there is a machine whose structure makes it think, sense, and have perceptions, we could conceive it enlarged, keeping the same proportions, so that we could enter into it, as one enters a mill. Assuming that, when inspecting its interior, we will find only parts that push one another, and we will never find anything to explain a perception.

The thing about that is, we’ll never find anything to explain a mill, either. Honestly, Gottfried, all I see is pieces of wood and metal moving around; none of them have any milliness? How on earth could a collection of pieces of wood – just by virtue of being arranged in some functional way, you say – acquire completely new, distinctively molational qualities?

Newton in doubtConsciousness is not a problem, says Michael Graziano in an Atlantic piece that is short and combative. (Also, I’m afraid, pretty sketchy in places. Space constraints might be partly to blame for that, but can’t altogether excuse some sweeping assertions made with the broadest of brushes.)

Graziano begins by drawing an analogy with Newton and his theory of light. The earlier view, he says, was that white light was pure, and colour happened when it was ‘dirtied’ by contact with the surfaces of coloured objects. The detail of exactly how this happened was a metaphysical ‘hard problem’. Newton dismissed all that by showing first, that white light is in fact a mixture of all colours, and second, that our vision produces only an inaccurate and simplified model of the reality, with only three different colour receptors.

Consciousness itself, Graziano says, is also a misleading model in a somewhat similar way, generated when the brain represents its own activity to itself. In fact, to be clear, consciousness as represented doesn’t happen; it is a mistaken construct, the result of the good-enough but far from perfect apparatus bequeathed to us by evolution (this sounds sort of familiar).

We should be clear that it is really Hard Problem consciousness that is the target here, the consciousness of subjective experience and of qualia. Not that the other sort is OK: Graziano dismisses the Easy Problem kind of consciousness, more or less in passing, as being no problem at all…

These days it’s not hard to understand how the brain can process information about the world, how it can store and recall memories, how it can construct self knowledge including even very complex self knowledge about one’s personhood and mortality. That’s the content of consciousness, and it’s no longer a fundamental mystery. It’s information, and we know how to build computers that process information.

Amazingly, that’s it. Graziano writes in an impatient tone; I have to confess to a slight ruffling of my own patience here; memory is not hard to understand? I had the impression that there were quite a number of unimpeachably respectable scientists working on the neurology of memory, but maybe they’re just doing trivial detail, the equivalent of butterfly collecting, or who knows, philosophy? …we know how to build computers… You know it’s not the 1980s any more? Yet apparently there are still clever people who think you can just say that the brain is a computer and that’s not only straightforwardly true, but pretty much a full explanation? I mean, the brain is also meat, and we know how to build tools that process meat; shall we stop there and declare the rest to be useless metaphysics?

‘Information’, as we’ve often noted before, is a treacherous, ambiguous word. If we mean something akin to data, then yes, computers can handle it; if we mean something akin to understanding, they’re no better than meat cleavers. Nothing means anything to a computer, while human consciousness reads and attributes meanings with prodigal generosity, arguably as its most essential, characteristic activity. No computer was ever morally responsible for anything, while our society is built around the idea that human beings have responsibilities, rights, and property. Perhaps Graziano has debunking arguments for all this that he hasn’t leisure to tell us about; the idea that they are all null issues with nothing worthwhile to be said about them just doesn’t fly.

Anyway, perhaps I should keep calm because that’s not even what Graziano is mainly talking about. He is really after qualia, and in that area I have some moderate sympathy with him; I think it’s true that the problem of subjective experience is most often misconceived, and it is quite plausible that the limitations of our sensory apparatus and our colour vision in particular contribute to the confusion. There is a sophisticated argument to be made along these lines: unfortunately Graziano’s isn’t it; he merely dismisses the issue: our brain plays us false and that’s it. You could perhaps get away with that if the problem were simply about our belief that we have qualia; it could be that the sensory system is just misinforming us, the way it does in the case of optical illusions. But the core problem is about people’s actual direct experience of qualia. A belief can be wrong, but an experience is still an experience even if it’s a misleading one, and the existence of any kind of subjective experience is the real core of the matter. Yes, we can still deny there is any such thing, and some people do so quite cogently, but to say that what I’m having now is not an experience but the mere belief that I’m having an experience is hard and, well, you know, actually rather metaphysical…

On examination I don’t think Graziano’s analogy with Newton works well. It’s not clear to me why the ‘older’ view is to be characterised as metaphysical (or why that would mean it was worthless). Shorn of the emotive words about dirt, the view that white light picks up colour from contact with coloured things, the way white paper picks up colour from contact with coloured crayons, seems a reasonable enough scientific hypothesis to have started with. It was wrong, but if anything it seems simpler and less abstract than the correct view. Newton himself would not have recognised any clear line between science and philosophy, and in some respects he left the true nature of light a more complicated matter, not fully resolved. His choice of particles over waves has proved to be an over-simplification and remains the subject of some cloudy ontology to this day.

Worse yet, if you think about it, it was Newton who first separated the two realms: colour as it is in the world and colour as we experience it. This is the crucial distinction that opened up the problem of qualia, first recognisably stated by Locke, a fervent admirer of Newton, some years after Newton’s work. You could argue therefore, that if the subject of qualia is a mess, it is a mess introduced by Newton himself – and scientists shouldn’t castigate philosophers for trying to clear it up.

Locke with flowersThe problem of qualia is in itself a very old one, but it is expressed in new terms.  My impression is that the actual word ‘qualia’ only began to be widely used (as a hot new concept) in the 1970s.  The question of whether the colours you experience in your mind are the same as the ones I experience in mine, on the other hand, goes back a long way. I’m not aware of any ancient discussions, though I should not be at all surprised to hear that there is one in, say, Sextus Empiricus (if you know one please mention it): I think the first serious philosophical exposition of the issue is Locke’s in the Essay Concerning Human Understanding:

“Neither would it carry any imputation of falsehood to our simple ideas, if by the different structure of our organs, it were so ordered, that the same object should produce in several men’s minds different ideas at the same time; e.g. If the idea, that a violet produced in one man’s mind by his eyes, were the same that a marigold produces in another man’s, and vice versa. For since this could never be known: because one man’s mind could not pass into another man’s body, to perceive, what appearances were produced by those organs; neither the ideas hereby, nor the names, would be at all confounded, or any falsehood be in either. For all things, that had the texture of a violet, producing constantly the idea, which he called blue, and those that had the texture of a marigold, producing constantly the idea, which he as constantly called yellow, whatever those appearances were in his mind; he would be able as regularly to distinguish things for his use by those appearances, and understand, and signify those distinctions, marked by the names blue and yellow, as if the appearances, or ideas in his mind, received from those two flowers, were exactly the same, with the ideas in other men’s minds.”

Interestingly, Locke chose colours which are (near enough) opposites on the spectrum; this inverted spectrum form of the case has been highly popular in recent decades.  It’s remarkable that Locke put the problem in this sophisticated form; he managed to leap to a twentieth-century outlook from a standing start, in a way. It’s also surprising that he got in so early: he was, after all, writing less than twenty years after the idea of the spectrum was first put forward by Isaac Newton. It’s not surprising that Locke should know about the spectrum; he was an enthusiastic supporter of Newton’s ideas, and somewhat distressed by his own inability to follow them in the original. Newton, no courter of popularity, deliberately expressed his theories in terms that were hard for the layman, and scientifically speaking, that’s what Locke was. Alas, it seems the gap between science and philosophy was already apparent even before science had properly achieved a separate existence: Newton would still have called himself a natural philosopher, I think, not a scientist.

It’s hard to be completely sure that Locke did deliberately pick colours that were opposite on the spectrum – he doesn’t say so, or call attention to their opposition (there might even be some room for debate about whether  ‘blue’ and ‘yellow are really opposite) but it does seem at least that he felt that strongly contrasting colours provided  a good example, and in that respect at least he anticipated many future discussions. The reason so many modern  theorists like the idea is that they believe a switch of non-opposite colour qualia would be detectable, because the spectrum would no longer be coherent, while inverting the whole thing preserves all the relationships intact and so leaves the change undetectable. Myself, I think this argument is a mistake, inadvertently transferring to qualia the spectral structure which actually belongs to the objective counterparts of colour qualia. The qualia themselves have to be completely indistinguishable, so it doesn’t matter whether we replace yellow qualia with violet or orange ones, or for that matter, with the quale of the smell of violets.

Strangely enough though Locke was not really interested in the problem; on the contrary, he set it out only because he was seeking to dismiss it as an irrelevance. His aim, in context, was to argue that simple perceptions cannot be wrong, and the possibility of inconsistent colour judgements – one person seeing blue where another saw yellow – seemed to provide a potential counter-argument which he needed to eliminate. If one person sees red where another sees green, surely at least one of them must be wrong? Locke’s strategy was to admit that different people might have different ideas for the same percept (nowadays we would probably refer to these subjective ideas of percepts as qualia), but to argue that it doesn’t matter because they will always agree about which colour is, in fact yellow, so it can’t properly be said that their ideas are wrong. Locke, we can say, was implicitly arguing that qualia are not worth worrying about, even for philosophical purposes.

This ‘so what?’ line of thought is still perfectly tenable. We could argue that two people looking at the same rose will not only agree that it is red, but also concur that they are both experiencing red qualia; so the fact that inwardly their experiences might differ is literally of no significance – obviously of no practical significance, but arguably also metaphysically nugatory. I don’t know of anyone who espouses this disengaged kind of scepticism, though; more normally people who think qualia don’t matter go on to argue that they don’t exist, either. Perhaps the importance we attach to the issue is a sign of how our attitudes to consciousness have changed: it was itself a matter of no great importance or interest to Locke.  I believe consciousness acquired new importance with the advent of serious computers, when it became necessary to find some quality  with which we could differentiate ourselves from machines. Subjective experience fit the bill nicely.