Thursday, December 10, 2009
Rosenberg responds to his critics
Well, sort of (scroll to the bottom). It seems to me that he mainly just repeats what he already said in his original piece, this time with a little testiness. I certainly don’t think he grapples seriously with the main difficulties facing his position (some of which I outlined in my earlier post).
Eliminative materialists like to complain that they are always being falsely accused of incoherently “believing that there are no beliefs” – “as if I had never heard of the ploy and would be stopped dead in my tracks by it,” says Rosenberg, making this complaint his own. “Actually,” he continues, “you won’t find the locution ‘I believe that….’ any where in my précis… just to avoid such puerile objections.” But does Rosenberg really think we anti-eliminativists have never heard that dodge before? Yes, fine, we realize that advocates of eliminative materialism (EM) studiously avoid the word “belief,” lest they be refuted in ten seconds rather than ten minutes. The trouble is that they inevitably help themselves to some other concept which leads them into exactly the same sort of incoherence, even if in a more subtle way.
In Rosenberg’s case, after reiterating that there is no such thing as “aboutness” or intentionality, he tells us in the same breath that “the brain receives, stores, and conveys information… [and] misinformation.” But “information” and “misinformation” are themselves intentional notions. (For you non-philosophers, “intentional” in this context means “exhibiting intentionality.”) This is obviously true of the ordinary, everyday sense of “information.” But it is also true of the technical, information-theoretic sense that Rosenberg has in mind – or at least, it has to be true of it if the notion of “information” is going to do the work Rosenberg and other naturalists need it to do. In particular, it has to be true if EM is to leave open the possibility of “naturalistically” reconstructing the notion of a “true” “theory” – such as a scientific theory, or a philosophical theory like naturalism or EM itself. And EM must reconstruct it somehow, otherwise the scribbles we make when we type things like “The Disenchanted Naturalist’s Guide to Reality” will no more count as correct guides to reality than do books on astrology, or indeed, than do the scratches my chair is making on the wood floor below me as I type this.
As John Searle has emphasized, the causal chains information theory regards as carriers of information – the processes that lead up to a tree’s having 33 rings, for example – count as “information” only in the sense that an outside observer can infer certain things from them. For example, someone counting the rings in question can, given his knowledge of elementary botany, infer that the tree is 33 years old, in a way he could not infer this from other aspects of the tree. But if we remove the observer and focus only on the objective physical facts, what we are left with is merely a set of causal processes having no more inherent significance than any others have. A year’s worth of growth caused a new ring to appear. It also thereby caused the tree get a little thicker; and the growth was itself caused in part by the presence of water in the soil around the tree’s roots. The collection of such causal chains is what exists objectively. But what makes the ring specifically – as opposed to the thickness or some other effect – significant with respect to the age of the tree specifically – as opposed to the water or some other cause? What makes the one “the” thing about which the other is “the” thing that conveys the “information”? The answer to both questions can only be the presence of an outside observer who takes these two particular points in the overall causal situation to have such significance. Absent the observer, to speak of “information” is just to speak of the enormously intricate network of causes and effects itself, but where no one part of it is more or less “informative” than any other. (This is a point which, as I noted in an earlier post, has been emphasized by Karl Popper and Hilary Putnam.)
More to the present point, the causal chains in Rosenberg’s brain, for example, will in this de-intentionalized sense of “information” no more count as a correct “guide to reality” – or as some “naturalistically respectable” “successor” to the concept of a “correct” “guide” – than the causal chains in his pancreas or his large intestine do, or indeed than the causal chains holding between my chair and the wood floor do. To be sure, an outside observer might be able to infer things from what is going on in the brain that he couldn’t infer from the intestine or the chair. But there is nothing left corresponding to such an inference – and in particular, nothing left that could correspond to a “correct” “guide to reality” (one that might be typed out as an essay and then cut and pasted onto a website, say) or any EM analogue to such a guide – when the observer is removed from the picture. There is just causation qua causation.
So, for the term “information” to do what Rosenberg needs it to do, it has to retain its intentional connotations. But in that case we are back to the problem that EM is incoherent insofar as it has to make use of concepts of the very sort it officially rules out. Yes, this need not be as crude as “believing there are no beliefs,” but as with the white collar criminal who eschews mugging but has no qualms about embezzling, the end result is essentially the same.
One reason Rosenberg fails to see this is that he says that the information the brain stores is not propositional or sentential in form, and he seems to think that this entails that it is not intentional. But whether the information in question is propositional or not is irrelevant to the point at issue, because propositional content is not essential to intentionality. What is essential to intentionality is directedness upon an object, and this “directedness” need not involve the expressing of a proposition about the object. It may be a mere “pointing to” the object without the making of a “statement” about it. Thus, even if the “information” Rosenberg says the brain contains does not amount to complete propositions, if it is to do the work Rosenberg needs it to do it will still have to involve certain brain processes “pointing to” or being “directed at” certain specific things beyond themselves. Otherwise it cannot ground a “naturalistic” “successor” to or reconstruction of the concept of a “correct” “guide to reality.” For example, whatever it is that is going on in neuroscientists’ own brains when they come up with correct neuroscientific theories will have in some way to “point to” brains specifically, rather than (say) to plates of spaghetti, seaweed, or kidney stones.
Anyway, like other EM advocates, Rosenberg never actually tells us what the reconstruction in question will look like – that is, what exactly is going on in the brain that corresponds to “accepting a scientific theory” and “affirming naturalism,” if it isn’t the having of beliefs and other intentional mental states. And like other EM advocates, he assures us that it is in any event to future neuroscience rather than to current naturalistic philosophy that we must look in order to find these things out. Rosenberg dismisses as “puerile” and a “trivial ploy” the claim that EM is self-undermining. “If only philosophy were that easy,” he laments. But it isn’t easy in that way. Instead, it’s easy in this way: Don’t bother me with your objections to EM. The neuroscientists will answer them some day, probably after I’m dead.
But the problem is not merely that this fails to answer the question. The problem is that it begs the question, because whether neuroscience can solve such philosophical problems – indeed, whether it is coherent to suggest that EM or any other claim can be restated, even at some future date, in a way that involves only non-intentional neuroscientific concepts – are precisely what is at issue. Moreover, Rosenberg never answers the question raised in my original post about why exactly we are supposed to accept EM if (a) EM entails that there is no fact of the matter about whether any argument, including any argument Rosenberg has given or could give for EM, is valid, sound, inductively strong, etc., and (b) neuroscience has at this point given us no “successor” concepts to validity, soundness, inductive strength, etc. Rosenberg is implicitly conceding that he has as yet no coherent way either of stating his position or arguing for it. Instead, he is issuing a promissory note that he assures us some future neuroscientists – someday, or some century, or some millennium – will make good on. Nor will they even give us (or our distant descendants) actually “rationally compelling” “arguments” for a “claim,” but rather a something-or-other (we know not what) that is somehow-or-other (we know not how) a “successor” of what we now call a rationally compelling argument for a claim. Why on earth should anyone accept such a bizarre promissory note? (Imagine some avant-garde mathematician told you that 2 + 2 = 23, admitted that he had no way of establishing this claim or even making it intelligible, but insisted that the mathematicians of the future would someday be able to do so. Would you take him seriously? Me neither, but there’s a guy at Duke University who would, and if you have any bridges for sale you might look him up.)
Rosenberg’s only answer is to beg the question some more, and indeed to repeat himself some more, with some hand-waving about what was “ruled out” by 17th century physics or “explained away” by Darwin. I’ve already explained what is wrong with this sort of move in my previous post on Rosenberg, and at great length in The Last Superstition.
So, why do Rosenberg, the Churchlands, and other EM advocates insist repeatedly on dismissing or even ignoring objections that are so obvious, and so obviously fatal, to their position? Part of the answer, as I’ve noted before, has to do with the ideological or even quasi-religious status naturalism has taken on in the thinking of so many contemporary philosophers – a status acknowledged by philosophers like Tyler Burge, William Lycan, Thomas Nagel, and John Searle (all quoted to this effect in The Last Superstition).
But there is likely a more personal component as well. The logical positivists no doubt thought that refuting their verifiability criterion of meaning just couldn’t be as easy as pointing out that it is self-undermining. “I’m A. J. Freaking Ayer! I don’t make obvious mistakes like that!” Actually, Freddie, you do. And here’s the painful truth: So do Paul Freaking Churchland and even Alex Freaking Rosenberg. If you don’t know it now, fellas, you’ll know it by the time you’re ready for your own Library of (Barely) Living Philosophers volumes. But be of good cheer – in contemporary academic philosophy, what is grounds for failing an undergraduate paper can be Festschrift material for a professional.