Friday, November 30, 2012
Nagel and his critics, Part IV
Continuing our look at the critics of Thomas Nagel’s recent book Mind and Cosmos, we turn to philosopher Alva Noë’s very interesting remarks over at NPR’s 13.7: Cosmos & Culture blog. Noë’s initial comments might seem broadly sympathetic to Nagel’s position. He writes:
Science has produced no standard account of the origins of life.
We have a superb understanding of how we get biological variety from simple, living starting points. We can thank Darwin for that. And we know that life in its simplest forms is built up out of inorganic stuff. But we don't have any account of how life springs forth from the supposed primordial soup. This is an explanatory gap we have no idea how to bridge.
Science also lacks even a back-of-the-envelop [sic] concept explaining the emergence of consciousness from the behavior of mere matter. We have an elaborate understanding of the ways in which experience depends on neurobiology. But how consciousness arises out of the action of neurons, or how low-level chemical or atomic processes might explain why we are conscious — we haven't a clue.
We aren't even really sure what questions we should be asking.
These two explanatory gaps are strikingly similar… In both cases we have large-scale phenomena in view (life, consciousness) and an exquisitely detailed understanding of the low-level processes that sustain these phenomena (biochemistry, neuroscience, etc). But we lack any way of making sense of the idea that the higher-level phenomena just come down to, or consist of, what is going on at the lower level.
End quote. Now an Aristotelian would say that this is precisely what we should expect. What modern biologists and neuroscientists have uncovered in exquisite detail are the material-cum-efficient causes of the phenomena of life and consciousness. But that is only half the story, for there are also irreducible final and formal causes -- the inherent teleological features natural objects exhibit by virtue of their substantial forms -- and you are never going to capture those features in terms of material and efficient causality. That is (one reason) why there always seems to be something left out in materialist accounts of life and consciousness.
There is a mystery here only if you suppose that “lower-level” descriptions are somehow more privileged than “higher-level” descriptions. And that, we old-fashioned Aristotelians would argue, is something there is no good reason to believe in the first place. It is merely a metaphysical dogma -- as old as Democritus and Leucippus but no more plausible now than it was in their day -- that is read into the scientific facts rather than read out of them. In the case at hand, what Noë is describing confirms the traditional Aristotelian view that there is a difference in kind and not merely degree between the organic and the inorganic, and between sensory and vegetative forms of life (in the technical Aristotelian sense of “vegetative,” which does not correspond exactly to the colloquial use of that term).
This has nothing to do with vitalism, “Intelligent Design” theory, and other such bogeymen, and one reason Nagel’s inchoate neo-Aristotelianism may be troubling to his more ideological critics is precisely that it undermines the false dilemma that is the naturalist’s main rhetorical weapon: “Either accept some form of naturalism or you’ll be stuck with magic, obscurantism, or a god-of-the-gaps.” For though Nagel’s own version is inchoate, neo-Aristotelianism cannot be dismissed as philosophically unserious, and has been worked out in more systematic detail by a number of prominent contemporary philosophers. (I noted several examples in the first post in this series. For a recent defense of a neo-Aristotelian position in biology, specifically, see David Oderberg’s Real Essentialism. I’ve criticized biological reductionism from an Aristotelian point of view in several earlier posts, such as this one, this one, and this one; and neuroscientific reductionism in several other posts, such as this one and this one.)
Now, Noë himself is no ideologue. This is evidenced not only by the comments already cited, but by his recognition of the depth of the difficulties facing materialism, and of their roots in the very nature of the scientific revolution:
The scientific revolution took its impulse from what the philosopher Bernard Williams called the Absolute Conception of Reality. This is a conception of the world as "it really is" entirely apart from how it appears to us: a colorless, odorless value-free domain of particles and complexes moving in accordance with timeless and immutable mathematical laws. The world so conceived has no place for mind in it. No intention. No purpose. If there is mind — and of course the great scientific revolutionaries such as Descartes and Newton would not deny that there is mind — it exists apart from and unconnected to the material world as this was conceived of by the New Science.
If modern science begins by shaping a conception of the cosmos, its subject matter, in such a way as to exclude mind and life, then it shouldn't come as a surprise that we can't seem to find a place for them in the natural order so conceived.
This is why Nagel observes, at the beginning of his book, that the mind-body problem isn't just a local problem concerning brains, behavior and the mind; correctly understood it invades our understanding of the cosmos itself and its history.
End quote. This is a point I’ve emphasized in my own work many times and which (as I’ve emphasized in the earlier posts in this series) has informed Nagel’s own thinking since his article “What Is It Like to Be a Bat?” Though materialists sometimes suggest that dualism represents a reluctance consistently to follow out the implications of the scientific revolution, the truth is precisely the reverse -- in fact it was the re-conception of matter put forward by the founders of the scientific revolution that led to (Cartesian forms of) dualism.
Noë even dismisses as “superficial and unsatisfying” the suggestion of critics like Brian Leiter and Michael Weisberg that Nagel’s arguments have little merit given that most philosophers today would probably reject the claim that neuroscience, biology, and chemistry can all be reduced to physics. For as Noë correctly observes:
[T]here is no stable or deeply understood account of how these autonomous domains fit together. The fact that we are getting along with business as if there were such an account is, well, a political or sociological fact about us that should do little to reassure.
End quote. As I noted in the two previous posts in this series, the autonomy of these sciences, far from saving naturalism from critiques like Nagel’s, itself only provides further vindication of the holistic Aristotelian account of the natural phenomena studied by these special sciences -- just the sort of position toward which Nagel points, however sketchily.
All the same, Noë resists following Nagel’s call for a radical rethinking of the naturalist consensus. (And now I get to justify my illustration of Noë as playing Dr. No to Nagel’s James Bond. All in fun, Prof. Noë!) Noë proposes instead that:
[T]here is another strategy for responding to the explanatory gaps. This has been one of philosophy's orthodox strategies at least since Kant and it is an approach championed by many of the 20th century's greatest thinkers, from Carnap and the logical positivists down through Wittgenstein and Ryle, to Dennett. According to this strategy, the seeming gaps are, really, a cognitive illusion. We think we can't explain life, but only because we insist on adhering to a conception of life as vaguely spooky, some sort of vital spirit. And likewise, we think we can't explain consciousness, but again this is because we cling to a conception of consciousness as, well, somehow spiritual, and precisely because we insist on thinking of it as something that floats free of its physical substrates ("a ghost in the machine"), as something essentially interior and private. Once we clear away these confusions, so this alternative would have it, we realize that we don't need to solve any special problems about life and mind. There never were any problems.
End quote. There are several things that can be said in response to this strategy. For one thing, and as I have already indicated, “vital spirits,” ghosts, and the like are straw men, at least if directed at Aristotelianism. (Though frankly, they’re not really fair against Cartesianism either, but I’ll let the Cartesians defend themselves.) It simply is not the case that to reject materialistic naturalism is to opt for magical or otherwise “spooky” forces and entities; it is, rather, simply to opt for an alternative metaphysics (and I have explained the difference between magic and metaphysics elsewhere). Of course, Noë might not really be suggesting that critics of materialistic naturalism are committed to magic or other pseudo-explanations. He may merely be suggesting that explanations of a materialistic naturalist sort are preferable to non-materialist explanations, even if the latter are genuine explanations. But if that is what he means then he is begging the question, since whether materialistic explanations are to be preferred to non-materialist ones is part of what is at issue in the larger debate between Nagel and his critics.
But put to one side the question of what positive alternatives there might be to the materialistic naturalism that is Nagel’s target -- neo-Aristotelian hylemorphism, Cartesian dualism, vitalism, idealism, panpsychism, neutral monism, or whatever. Noë’s response would fail even if none of these alternatives was any good. To see why, suppose that a critic of Gödel's incompleteness theorems suggested that every true arithmetical statement in a formal system capable of expressing arithmetic really is in fact provable within the system, and that the consistency of arithmetic can in fact be proved from within arithmetic itself -- and that Gödel's arguments seem to show otherwise only because of a “cognitive illusion” that makes formal systems seem “vaguely spooky.”
This would not be a serious response to Gödel precisely because it simply does not show that Gödel is wrong but either presupposes or merely asserts that he is wrong. Gödel purports to demonstrate his claims. Hence, adequately to answer him would require showing that there is something wrong with his attempted demonstration, not merely staking out a position that assumes that there is something wrong with it. Similarly, many of the key arguments against materialistic naturalism -- Chalmers’ “zombie argument,” Jackson’s “knowledge argument,” Ross’s argument for the immateriality of thought, etc. -- purport to demonstrate that materialistic naturalism is false. Adequately to answer them requires showing that there is some error in the attempted demonstrations, and the appeal to an alleged “cognitive illusion” simply assumes this without showing it. It merely begs the question.
Furthermore, there would only be pressure to take the “cognitive illusion” suggestion seriously if we had independent reason to think that materialistic naturalism simply has to be right. And there is no such reason. Its defenders often point to the “success” of materialistic explanations as reason to think materialistic naturalism is true, but as I have pointed out many times (e.g. here), this sort of argument, however popular, is blatantly fallacious. To argue:
1. The predictive power and technological applications of materialistic modes of explanation are unparalleled by those of any other purported source of knowledge.
2. Therefore what materialistic explanations reveal to us is all that is real.
is as silly as arguing:
1. Metal detectors have had far greater success in finding coins and other metallic objects in more places than any other method has.
2. Therefore what metal detectors reveal to us (coins and other metallic objects) is all that is real.
Metal detectors are keyed to those aspects of the natural world susceptible of detection via electromagnetic means (or whatever). But however well they perform this task -- indeed, even if they succeeded on every single occasion they were deployed -- it simply wouldn’t follow for a moment that there are no aspects of the natural world other than the ones they are sensitive to. Similarly, what materialistic explanations do is to capture those aspects of the natural world susceptible of a materialist analysis -- breaking down larger systems into component material parts, mathematically modeling the parts and their combinations, testing the predictions that follow from these models, and so forth. But here too, it simply doesn’t follow for a moment that there are no other aspects of the natural world.
Suppose someone beholden to the idea that coins and other metallic objects are all that exist was confronted with all the obvious counterevidence -- trees, rocks, people, animals, glass, plastic, and all the other non-metal objects there are. And suppose he acknowledged that there is an “explanatory gap” here but that it rested on a “cognitive illusion” that made trees, rocks, etc. seem “vaguely spooky” insofar as they appeared to “float free of their metallic substrates.” Of course, no one would take such an absurd suggestion seriously for a moment. But neither is there any non-question-begging reason to take seriously the suggestion that all the counterevidence to materialistic naturalism rests on a “cognitive illusion.”
As E. A. Burtt warned in his classic book The Metaphysical Foundations of Modern Physical Science, those impressed by the methods of modern science are prone to “make a metaphysics out of [that] method,” to judge reality by the method rather than judging the method against reality. That is in fact the “cognitive illusion” operative in the debate between materialistic naturalism and its critics, and it seems it is an illusion to which even a reasonable man like Noë might be subject.