Sunday, January 27, 2013
H. Allen Orr on Nagel
H. Allen Orr is a biologist and a frequent player at the New York Review of Books. The latter makes for essential reading both because and in spite of the fact that it is dedicated to defending a leftist orthodoxy. Orr has been called on before, if my memory is correct, to debunk evolutionary psychology, with which the leftist orthodoxy is uncomfortable.
Orr takes on Thomas Nagel’s book which I have been commenting on here. It is an odd bit of debunking as it certainly attacks Nagel on some key points but, I think, sort of agrees with his larger point.
Orr puts Nagel’s thesis in these terms:
Nagel insists that the mind-body problem “is not just a local problem” but “invades our understanding of the entire cosmos and its history.” If what he calls “materialist naturalism” or just “materialism” can’t explain consciousness, then it can’t fully account for life since consciousness is a feature of life. And if it can’t explain life, then it can’t fully account for the chemical and physical universe since life is a feature of that universe. Subjective experience is not, to Nagel, some detail that materialist science can hand-wave away. It’s a deal breaker. Nagel believes that any future science that grapples seriously with the mind-body problem will be one that is radically reconceived.
That is the point that is essential in Nagel’s book and I think that Orr comes very close to conceding it.
Nagel concedes that many philosophers do not share his skepticism about the plausibility of reducing mind to matter. And I can assure readers that most scientists don’t. I, however, share Nagel’s sense of mystery here. Brains and neurons obviously have everything to do with consciousness but how such mere objects can give rise to the eerily different phenomenon of subjective experience seems utterly incomprehensible.
Yes. Is it possible that some really big leap in science is required before consciousness can be accounted for, as Nagel insists?
Science has, since the seventeenth century, proved remarkably adept at incorporating initially alien ideas (like electromagnetic fields) into its thinking. Yet most people, apparently including Nagel, find the resulting science sufficiently materialist. The unusual way in which physicists understand the weirdness of quantum mechanics might be especially instructive as a crude template for how the consciousness story could play out. Physicists describe quantum mechanics by writing equations. The fact that no one, including them, can quite intuit the meaning of these equations is often deemed beside the point. The solution is the equation. One can imagine a similar course for consciousness research: the solution is X, whether you can intuit X or not. Indeed the fact that you can’t intuit X might say more about you than it does about consciousness.
Orr doesn’t seem to recognize how big a leap was involved in quantum mechanics. Prior to the emergence of that field of physics, most scientific theory was resolute deterministic. Every particle was at one place at one time and the state of every closed system rigidly determined the state of the system at all points in time. Quantum mechanics allows particles to be in more than one place and state at one time and for authentically undetermined events. If probability is not merely a limitation on our powers of prediction and instead something metaphysically real in the way that gravity is real, then materialism has a metaphysically new meaning.
It might be that consciousness is simply something we cannot understand because our perspective as conscious creatures blinds us to it, a possibility that Orr considers. It may be however that the nature underlying consciousness is, like quantum indeterminacy, something radically new to science. If so, then Nagel is on to something.
The lesser point of Nagel’s argument is that materialist biology is empirically wanting, as it is simply inadequate to explain the rise of complex forms of life. Nagel suggests that only some kind of natural teleology can meet that challenge. As Orr puts Nagel’s view:
Natural teleology doesn’t depend on any agent’s intentions; it’s just the way the world is. There are teleological laws of nature that we don’t yet know about and they bias the unfolding of the universe in certain desirable directions, including the formation of complex organisms and consciousness. The existence of teleological laws means that certain physical outcomes “have a significantly higher probability than is entailed by the laws of physics alone—simply because they are on the path toward a certain outcome.”
Orr responds with some very interesting summaries of evolutionary biology, including the difference between DNA and RNA. I have no reason to quarrel with this except to point out that it should be possible to show mathematically that the complexity of life is within the powers of these simple molecules to produce. Maybe it is, but has anyone show that it is?
Unfortunately, Orr fails to make a fundamental distinction between teleology as a factor in biological explanations, which he sort of acknowledges as reasonable, and teleology as a factor in the appearance of life on earth. It is the latter that Nagel argues for. Nagel says that scientists who study the origin of life generally believe that mere chance was insufficient to account for the emergence of the original replicators from which all other life evolved. Is he right? If not chance, then what? I have consideredNagel’s argument on “unintentional forcing” as an explanation for the emergence of life. Orr is silent on this.
Orr’s review is respectful but is clearly intended to blunt the force of Nagel’s argument. I have to say that, having read it, Nagel looks to be more rather than less worthy of taking seriously.