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.
One comment on your blog. The white text on a red background is difficult to read. At least I find it so. I suggest you change the color scheme.
ReplyDeleteXenophon: I will give this some thought.
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