Saturday, December 1, 2012

Thomas Nagel: in search of his mind

Unfortunately, he is looking in all the wrong places, following his intuition.

Philosophy is in a bad state. All problems with any hope of resolution have hived off to other fields. Its star scholars are not taken seriously in the wider culture, other than the occasional charismatic performance artist, like Zizek. It is left ruminating on the perennial "big questions", worshipping at the altar of Plato, and claiming to be the last redoubt of reason and critical thought in an ever more classical-averse culture.

Which is odd, since the ultimate resource and criterion of the contemporary philosopher appears to be his or her own intuition. Each defends her intuition with whatever rhetoric and precedent she can bring to bear, and criticizes that of other philosophers, though with the decorum appropriate to an ecumenical community of not-very-rational belief systems with little hope of resolution or reconciliation. If it were up to me, their academic departments would be renamed Departments of the History of Philosophy, and they would give up any pretense (doubtless owing to physics-envy) of doing "research" or of making "progress".
"The best we can do is to develop the rival alternative conception in each important domain as fully and carefully as possible, depending on our antecedent sympathies, and see how they measure up. That is the more credible form of progress than decisive proof or refutation." - Nagel on doing philosophy.

This week's example is Thomas Nagel, whose recent book, "Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False", sets out his intuitions on several topics, and follows them out to their cracked conclusions. (Hat tip to Darrell for suggesting it.) At least he claims to be an atheist- one intuition I can agree with. But on every other count- on consciousness being non-material, on reason being inexplicable by evolution, on moral realism, and on the (lack of) explanatory power of evolutionary theory generally, he would rather overturn our understanding of the cosmos than give up his favorite intuition.

Nagel writes very well, and is apparently one of the most eminent philosophers of our day. The book is brief and clear. Unfortunately, this brutally exposes his arguments in a way that other philosophers typically, and perhaps wisely, avoid. Take intelligent design (ID). Nagel makes it clear that he is no fan of theism or theistic explanations of biology. But he takes the intelligent design critique pretty much at face value, with horrified sprinklings of "chemical accident", "random chance", "dead matter", "accidental mutation", and "purely chemical" in his argument. Speaking of ID proponents: "They do not deserve the scorn with which they are commonly met. It is manifestly unfair." Following this school, he doubts not only the capacity of chemistry to explain the origin of life, but of mutation and natural selection to explain the profusion of life's diversity, particularly the origin of his own amazing mind.
"In the present intellectual climate such a possibility is unlikely to be taken seriously, but I would repeat my earlier observation that no viable account, even a purely speculative one, seems to be available of how a system as staggeringly functionally complex and information-rich as a self-reproducing cell, controlled by DNA, RNA, or some predecessor, could have arisen by chemical evolution alone from a dead environment."

All this has been discussed ad infinitum elsewhere, and I hardly need to go into detail. But it is shocking to see this as a founding idea by a leading philosophical academic. Does he also impugn geology as a mere tissue of hypothesis, incapable of really telling us what went on in the Archean era? No. We can't all study the eternal and time-reversible particles of physics, and have to make do with the best theories we can muster and with the evidence at hand. He reserves his incredulity for biology because, as we all know, biological organisms are astoundingly complex and it is, to this armchair philosopher, incredible that evolutionary theory is equal to such astoundingness.
"I realize that such doubts will strike many people as outrageous, but that is because almost everyone in our secular culture has been browbeaten into regarding the reductive research program as sacrosanct, on the ground that anything else would not be science."

Needless to say, he has no better theory to offer, other than vague intimations of teleology and "mind". Nagel made his mark as a philosopher of mind, and retains a Platonic view (oh, that disastrous philosopher!) that the mind can not be reduced. His intuition is that subjective experience is fundamentally separate from, incommensurate with, and irreducible to, material existence. This attitude is what creates the dilemma, the need to question evolutionary theory, and the pining for some way to make of the mind a cosmic explanatory principle. It is not unusual to see this quest among new age cranks, but among scholarly philosophers? What millenium are we in?
(Parenthetically, one of his finest passages is on this divide between materialism and Platonic idealism:  "After all, whatever one's philosophical views, so long as there is such a thing as truth there must be some truths that don't have to be grounded in anything else. Disagreement over which truths these are defines some of the deepest fault lines of philosophy. To philosophers of an idealist pursuasion it is self-evident that physical facts can't just be true in themselves, but must be explained in terms of actual or possible experience. just as it is evident to those of a materialist pursuasion that mental facts can't just be true in themselves, but must be explained in terms of actual or possible behavior, functional organization, or physiology.")

He sees himself in search of a middle way, between the non-explanatory assertions of theism, and the insufficiently explanatory, but irritatingly hegemonic, claims of scientific materialism / naturalism. What does he find when he goes down his intuitive road, which apparently (and inexplicably) also puts him in search of transcendence(†)?

Here are a couple of summaries of his program:
"the respective inadequacies of materialism and theism as transcendent conceptions, and the impossibility of abandoning the search for a transcendent view of our place in the universe, lead to the hope for an expanded but still naturalistic understanding that avoids psychophysical reductionism. The essential character of such an understanding would be to explain the appearance of life, consciousness, reason, and knowledge neither as accidental side effects of the physical laws of nature nor as the result of intentional intervention in nature from without but as an unsurprising if not inevitable consequence of the order that governs the natural world from within. That order would have to include physical law, but if life is not just a physical phenomenon, the origin and evolution of life and mind will not be explainable by physics and chemistry alone. An expanded, but still unified, form of explanation will be needed, and I suspect it will have to include teleological elements."
"The implausibility of the reductive program that is needed to defend the completeness of this kind of naturalism provides a reason for trying to think of alternatives- alternatives that make mind, meaning, and value as fundmental as matter and space-time in an account of what is. The fundamental elements and laws of physics and chemistry have been inferred to explain the behavior of the inanimate world. Something more is needed to explain how there can be conscious, thinking creatures whose bodies are composed of those elements. If we want to try to understand the world as a whole, we must start with an adequate range of data, and those data must include the evident facts about ourselves."

At best, (i.e. in his most sane moments), he suggests that some new principle might make the usual evolutionary paradigm make sense. To explain this, I can offer the analogy of quantum mechanics. Some enzymes make use of electron tunneling, one of the more obscure aspects of the quantum world. This was not because some brainiac designer chose the most esoteric way to accomplish a difficult task, but because all aspects of natural reality are at hand in the evolutionary toolkit, ready to happen and be selected as means to success.

Likewise, Nagel would imagine that consciousness and especially the human style of rich consciousness demands some new element in reality, in addition to that of which we are already aware, which could close out the account of how subjectivity and mental activity broadly happen as part of the physical brain at the pinnacle of otherwise reasonably understood developmental and evolutionary processes.

But, critically, he has no idea what this new element might be. It might be some cosmic pan-psychism, or dark matter, or ... there is nothing there, no alternative hypothesis worth the name. He hammers on the point that to him, it "seems" that the mind is non-reducible, and uses that as his premise for all else in the book, including his vast project to destabilize if not overturn all of modern science, and introduce teleology into the cosmos.
"I am drawn to a fourth alternative, natural teleology, or teleological bias, as an account of the existence of biological possibilities on which natural selection can operate. I believe that teleology is a naturalistic alternative that is distinct from all three of the other candidate explanations: chance, creationism, and directionless physical law. To avoid the mistake that White finds in the hypothesis of nonintentional bias, teleology would have to be restrictive in what it makes likely, but without depending on intention or motives."

If you have ever taken physical chemistry, this line of argument is laughable. The possibilities that chemistry presents are well-known, and are pitilessly random. If some bias were present in the collisions of gasses and the jumbling of molecules, we would know about it by now... it is a topic of great interest, deep theory, and astonishing technological achievement.

Being charitable, one can say that, despite his bomb-throwing attempt to boost book sales, his suggestion in minimal terms is merely that nature is not yet fully understood, and something new may come along to explain minds and other pet philosophical issues (i.e. counter-materialist intuitions). In principle, this is fine. No one pretends that everything is understood in naturalist terms. Even in physics, despite the amazing completeness of the standard model, capped off by the Higgs boson discovery, there are clearly holes, such as dark matter and dark energy, not to mention the arrow of time and the origin of the cosmos.

So the real question is not whether naturalism is incomplete as a general philosophy or has explained everything, but whether it is wrong, (according to Nagel's subtitle: "almost certainly false"), whether there are in any particular instances a different and better hypothesis available, and in the specific case of biology, whether "something new" is needed at all to explain the mind/brain connection or anything else. I think not, and no work among those actually studying these issues points in this direction.

It is important to pay attention to the circumstantial evidence in this field and in biology generally, which points uniformly in materialist directions. Nothing we have learned about the brain so far (admittedly, not very far) has violated physics or materialism. Our thoughts happen at speeds acceptable under normal physics, lesions in the brain destroy thoughts and abilities ... it all makes sense. Do we have a full explanation of consciousness? Not yet, but at this late date, it strains credulity that our intuitions are telling us anything important about it. We need to follow evidence rather than intuition.

But Nagel will have his intuition, first and foremost:
"It seems conceivable, for any Ω, [the observable, objective properties of the brain], that there should be Ω without any experience at all. Experience of taste seems to be something extra, contingently related to brain state- something produced rather than constituted by the brain state. So, it cannot be identical to the brain state in the way that water is identical to H2O."

(Note the extremely heavy lifting done by the word "seems", moving the argument from a fanciful thought experiment to "cannot".)

Is what he is doing science? Well, perhaps, but not very good science. He is, as part of the intelligent design community, expressing doubts about the reigning theory. But without specific disproof, and without a better theory, these attacks are foolish. They are based on bare incredulity in the teeth of a great deal of countervailing direct and circumstantial evidence. My take on this assertion is that given a brain with all the structures, electrical activities, and hum of a working brain, (i.e. it would be alive), its subject would necessarily have experiences. Not only that, but that reproducing such experiences in artificial computers is something whose accomplishment is just a matter of time.

So far, we have not given a fig about the internal experience of computers, which contrasts sharply from the forces of evolution, which put motivation, continuity, and unity of conception and action foremost, thus leading understandably to computational machines that represent their output internally rather than on a printer. In any case, all studies of our cognition are consistent with its computational character, up to the point of subjective experience.

Lastly, once Nagel gets into the weakest point of his argument- his intuition that moral values are objective, (i.e. moral realism or value realism) which conveniently makes another argument for cosmic teleology. He admits, however:
"So I am in agreement with Street that, from a Darwinian perspective, the hypothesis of value realism is superfluous- a wheel that spins without being attached to anything. From a Darwinian perspective our impressions of value, if construed realistically, are completely groundless. And if that is true for our most basic responses, it is also true for the entire elaborate structure of value and morality that is built up from them by practical reflection and cultural development ... Nevertheless, I remain convinced that pain is really bad and not just something we hate, and that pleasure is really good, and not just something we like. That is just how they glaringly seem to me, however hard I try to imagine the contrary, and I suspect the same is true of most people. ... Indeed the disposition to ascribe an illusory objectivity to plainly contingent, response-dependent norms, of language and custom, for example, seems to be typical of humans, and quite useful."

Note once again the work that "seems" does here, and the excruciating work Nagel must do to deny the sensible model in favor of his intuitions, even being aware that his intuitions are perversely well-accounted for by the Darwinian theory. It is a breathtaking piece of philosophy!

He believes that, based on his intuitions about each of these issues, he has demonstrated the necessity of some non-physical explanations that go beyond the scientific / materialist / naturalist paradigm. I think these arguments are poorly founded in the extreme, and by the weight of current evidence incorrect on every count, even putting aside his failure to offer a competing model of any detail. It is high time to put intuition-based philosophy, not to mention intuition-based science and cosmology, out to pasture.




† Note on transcendence...
"Evolutionary naturalism implies that we shouldn't take any of our convictions seriously, including the scientific world picture on which evolutionary naturalism depends.
I will defend these claims in later chapters, but here let me say what would follow if they are correct. The failure of evolutionary naturalism to provide a form of transcendent self-understanding that does not undermine our confidence in our natural faculties should not lead us to abandon the search for transcendent self-understanding. There is no reason to allow our confidence in the objective truth of our moral beliefs, or for that matter our confidence in the objective truth of our mathematical or scientific reasoning, to depend on whether this is consistent with the assumption that those capacities are the product of natural selection."

Firstly, I think he confuses two cases- the case of moral concepts versus the other cases of mathematical and scientific concepts. Under evolution, morals are not objective, thus we should indeed be a bit more humble about our innate faculties and prejudices in this regard. Whatever our intuitions, it would be more accurate as well as helpful in practical affairs if we gave up the idea that morals are objective, particularly our own morals.

On the other hand, the idea that evolutionary theory destabilizes our other senses and especially our ability to accurately do math is simply wrong. No one questions that math is hard. We are not natural mathematicians, at least beyond the number of our fingers. But what we do have are ways to validate our work, looking for logical consistency and forms of calibration that supply the critical perspective that we innately may lack, on both mathematical and scientific issues.

More generally, we have evolved to possess general computational power. That means that we have not only, say, a graphics card (i.e. a visual system) dedicated to visual processing, but also a completely general ability to do logic on any topic we wish, typically assisted with language, pencil, paper, or other devices. This frees us mentally to analyze any question of interest and critique that analysis, devising fully logical answers (i.e. proofs) given a set of premises. These premises may be faulty or unfounded, but that is a separate issue.

So while our visual accuracy is perhaps dependent on the quality of our evolution, (with color-blind people being barred from certain perceptions in the absence of modern technologies, for instance), our logical perception is not dependent on the specifics of our wiring. It may go terribly slowly, but with enough work, we can come up with definitive answers that, yes, transcend our native perceptual abilities. That is the whole point of science and math.

So I do not think Nagel's premises are correct. His quest for transcendent self-understanding also is misguided. If he means a well-founded, objective scientific understanding that is correct within the bounds of current knowledge (i.e. will be ony be extended rather than disproven, in the sense of Einstein's work), then we already have such an understanding in many areas, particularly of biology. If he is pining for a religious perspective on the cosmic mind and its teleological principle, he is barking up the wrong tree entirely.


3 comments:

  1. Hi Burk,

    Sometimes I think that, while philosophy of X (where X may be biology, math, whatever) may constitute an important and useful critical analysis of X, there appears to be no equivalent for philosophy itself. Nagel's example shows that philosophy could profit from more rigorous criticism. Lacking this, well, anything goes, apparently.

    The worst is, as you describe, this so completely unjustifiable faith in “intuition”. One of my favourite counter-example is this well known visual illusion (in which A and B are exactly the same shade of grey). Our intuition clearly seems them as different and, if we are to accept Nagel's argument (That is just how they glaringly seem to me, however hard I try to imagine the contrary[...]), we would have to accept that they really are different. Because, if this works for moral values, why not for this much simpler case? It is simply mind-boggling that this argument has still so much traction among some philosophers.

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  2. Well, I don't think philosophy does such a great job analyzing the other sciences, either. It is institutionally a mess, unfortunately, infested with theists and anyone else with a metaphysical axe to grind. No evidence needed.

    For instance, a recent philosophy bites episode featured philosophers saying who their favorite philosopher was. Do you hear geologists asking who their favorite geologist was? Not really- they just take what is right, discard the rest, and progress on with their field. How many chemists would say "Lavoisier is my favorite chemist"? Many of the respondents said "Hume", but just as many said "Aristotle". Well, if they could settle their own affairs, I would look more kindly on their opinions about biology and the cosmos.

    Plantinga has a review of this book as well, where he gets in on the fun of disparaging fields he obviously knows nothing about. They are talking about the contents of reality, after all, and think that their precious intuition is the most incisive tool in the workshop. Well, it isn't.

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