An unfavorable but thought-provoking review
earlier this month in The New York Review of Books introduced me to both the renowned NYU philosopher Thomas Nagel and his
recent book, Mind
and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost
Certainly False. Even if
the review had been favorable, the subtitle of the book alone would normally have
caused me to shrug and move on to other things. Those who follow this blog know I'm not patient with
philosophical prattlings about the nature of the universe. (See my posting Whence the
Universe.) Nagel's book seemed to be of that ilk.
But I was arrested by a summary of Nagel's perspective given
by the reviewer:
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.
That reminded me of my son
David's panpsychism, which I mentioned last month in Philosophy,
Schmilosophy! He believes that all of creation is permeated
with consciousness and develops with an ethereal, beneficent
purpose. I embrace the
polar-opposite outlook, that the cosmos evolves purely randomly, without any
transcendental goal. I decided to
read Nagel's book to see if it might shed further light on this dichotomy.
***
First off, and a little disconcertingly, Nagel acknowledges
his debt to creationists for having kept alive the possibility of an
alternative to materialistic Darwinism.
He in fact joins them in three contentions: (1) the probability of an
accidental formation of self-reproducing living matter from inanimate matter is
infinitesimal; (2) even if living matter
did form randomly, against all odds, there hasn't been enough geologic
time for life with the biological and physical complexity of humans to have
evolved through random mutations alone; (3) consciousness is so
incomprehensible under a materialistic approach that a move beyond Darwinism is
necessary. Unlike creationists,
however, Nagel doesn't come to a theistic conclusion—an Intelligent Designer—from
these assertions. As an atheist,
he instead looks for a naturalistic addition to evolutionary theory.
Nagel devotes most of his book to the problem of
consciousness. Materialists
already have extensive neuroscientific evidence supporting their hope that
consciousness will eventually be explained as activity of the brain cells—mind
reduced to matter—but even they admit to currently being at a loss for a
complete schema. Nagel contends,
as in his subtitle, that such a materialist monism is almost certainly a false
trail. He also dismisses both the
dualism of Descartes, which almost entirely separates mind and matter; and the
reductionism of such idealist philosophers as Bishop Berkeley, who advance a
different sort of monism, that matter is reducible to mind, having no reality
other than as a mental construction.
Nagel instead adheres to a philosophical concept called neutral monism—that the
elementary stuff of which the universe is made is not purely physical or purely mental,
but indivisibly both, neither reducing to the
other.
Nagel's case for neutral monism is intuitive, expressed in assertions like the following, which I have spliced together from several pages of one of his chapters:
Nagel's case for neutral monism is intuitive, expressed in assertions like the following, which I have spliced together from several pages of one of his chapters:
Organisms such
as ourselves do not just happen to be
conscious; therefore no explanation of the physical character of those
organisms can be adequate which is not also an explanation of their mental
character. … A naturalistic expansion of evolutionary theory to account for
consciousness … would have to offer some account of why the appearance of
conscious organisms, and not merely of behaviorally complex organisms, was
likely. … It is not enough to say, "Something had to happen, so
why not this?" [Boldface is
mine.]
I have boldfaced the word "likely"
in this passage to emphasize Nagel's predicate of teleology: he calls for a
naturalistic explanation in which evolution is systematically driven toward the
development of conscious life rather than just life itself.
What could such a bias consist of? Nagel discards panpsychism—that consciousness permeates the
universe, making the evolution of conscious creatures likely. He opts instead for emergent
consciousness—that there are as yet
undiscovered natural laws which, together with the laws of biology, chemistry
and physics we already know, lead to consciousness in sufficiently complex
organisms.
Nagel offers no clue about what these additional laws might
be, only asserting that they must exist in order to explain consciousness and
such ancillary concepts as cognition and value-based behavior. But how can one's skepticism not be
stoked by the absence of any elaboration?
And, if his brand of neutral monism is truly neutral, driving evolution
toward consciousness in tandem with physical complexity, why wouldn't some
complex plants on Earth have developed signs of consciousness as well as many
complex animals? Indeed, why does Nagel's teleology strike one as implausibly
anthropocentric?
Despite my skepticism, I am not so negative about Nagel's
speculations as I was about the metaphysical pap I decried in Whence the
Universe, where I discussed the book Why does the World Exist? Much in
that book consists of wild imaginings which seemed to me to have no gloss of
rational thought. Nagel, on the
other hand, rationally postulates a missing element—unknown non-materialistic
laws—to fill out our understanding of consciousness, and tries to thrash out
the consequences of such a postulate.
Yet this postulate smacks of others that have been introduced
into science in attempts to accommodate the mysterious—for example, phlogiston
to explain the release of heat from burning material and the luminiferous æther
to explain how light could travel through a vacuum. Scientists eventually discovered how to remove those
intuitive but false suppositions.
Given Nagel's inability, other than through reference to his intuition,
to adduce any evidence to support his neutral monism, materialist monists like
myself will continue to expect and await an explanation of consciousness based
solely on biology, chemistry and physics.
***
Nagel's book neither changed my conception of the universe nor further
illuminated David's for me. More
to the point, I think Nagel presumes on a bygone relationship of philosophy to science. Many centuries ago, when science was
still called "natural philosophy," the ruminations of philosophers
about the nature of the universe still had an influence on science's
development, if only—as do Nagel's—by raising more questions than they answered. Since then, that influence has
continually diminished, to the point where it is now pretty much nil. Nagel's effort to turn back the clock
is quixotic.