As I’ve mentioned before, the respected philosopher of mind Thomas Nagel has joined the ranks of Darwin-dissers with the publication of his new book Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False. I am eager to read this, but haven’t yet had a chance because I’m travelling and reading Sophisticated Theology™ (this book may qualify in that genre).
Nagel has always evinced a sympathy for Intelligent Design creationism, and in fact he chose Stephen Meyer’s ID book Signature in the Cell as his “book of the year” in the respected Times Literary Supplement (read the letters following Nagel’s endorsement at the link). But Nagel is no slouch academically, and so it’s very surprising that he joins his colleague Jerry Fodor in bashing Darwin at book length.
In the latest issue of The Nation, Brian Leiter and Michael Weisberg review Nagel’s new book. Their verdict isn’t pretty.
Nagel’s is the latest in what has become a small cottage industry involving a handful of prominent senior philosophers expressing skepticism about aspects of Darwin’s theory of evolution by natural selection. Some, like the overtly Christian philosopher Alvin Plantinga, have made a career of dialectical ingenuity in support of the rationality of religious faith. Others, such as Jerry Fodor, are avowed atheists like Nagel, and have only tried to raise challenges to discrete aspects of evolutionary explanations for biological phenomena. Plantinga’s influence has largely been limited to other religious believers, while Fodor’s challenge was exposed rather quickly by philosophers as trading on confusions (even Nagel disowns it in a footnote). Nagel now enters the fray with a far-reaching broadside against Darwin and materialism worthy of the true-believing Plantinga (whom Nagel cites favorably). We suspect that philosophers—even philosophers sympathetic to some of Nagel’s concerns—will be disappointed by the actual quality of the argument.
Nagel not only attacks evolution and materialism, but, after touting Stephen Meyer, now gives encomiums to the unctuous Alvin Plantinga! One wonders if Nagel is losing his critical abilities, or simply is plagued by a nagging desire to go to church.
Weisberg and Leiter do agree, though, with one of Nagel’s beefs—the notion that reductionism is overrated:
Nagel opposes two main components of the “materialist” view inspired by Darwin’s theory of evolution by natural selection. The first is what we will call theoretical reductionism, the view that there is an order of priority among the sciences, with all theories ultimately derivable from physics and all phenomena ultimately explicable in physical terms. We believe, along with most philosophers, that Nagel is right to reject theoretical reductionism, because the sciences have not progressed in a way consistent with it. We have not witnessed the reduction of psychology to biology, biology to chemistry, and chemistry to physics, but rather the proliferation of fields like neuroscience and evolutionary biology that explain psychological and biological phenomena in terms unrecognizable by physics. As the philosopher of biology Philip Kitcher pointed out some thirty years ago, even classical genetics has not been fully reduced to molecular genetics, and that reduction would have been wholly within one field. We simply do not see any serious attempts to reduce all the “higher” sciences to the laws of physics.
Here all three academics (Weisberg is a philosopher; Leiter a professor of law) make a mistake: the view that all sciences are in principle reducible to the laws of physics, which is materialism, is not identical to an attempt to reduce all sciences to physics. The former must be true unless you’re religious, while the latter is a tactical problem that will be solved to some degree as we understand more about physics and biology, but is unlikely in our lifetime to give a complete explanation for higher-level phenomena. Remember, though, that “emergent phenomena” must be consistent with the laws of physics, even those laws may not be useful for explaining things like natural selection.
And, of course, more and more phenomena are being explained by physics. That’s what physical chemistry is all about, and even some aspects of natural selection (e.g., why eyes and ears evolved as they do) depend on knowing principles of physics.
But never mind. Nagel’s target appears to be naturalism, and his method similar to that of Plantinga, who believes that natural selection could never have given humans the ability to seek out and discover truths about nature:
The second component of the thesis Nagel opposes is what we will call naturalism, the view that features of our world—including “consciousness, intentionality, meaning, purpose, thought, and value”—can ultimately be accounted for in terms of the natural processes described by the various sciences (whether or not they are ever “reduced” to physics). Nagel’s arguments here are aimed at a more substantial target, although he gives us few specifics about the kind of naturalism he opposes. He does characterize it as the attempt to explain everything “at the most basic level by the physical sciences, extended to include biology,” and the one named proponent of this view is the philosopher Daniel Dennett. Although Dennett would not characterize his project as trying to explain everything at the “most basic level,” he does aim to show that phenomena such as consciousness, purpose and thought find a natural home in a picture of human beings inspired by Darwin. In the absence of any clearer statement of the argument, we will assume that this is the so-called “neo-Darwinian” picture that Nagel opposes.
One would assume that Nagel must be thoroughly acquainted with the evolutionary literature to make such a claim, but apparently he’s not near as savvy about our field as is Dennett:
Defending such a sweeping claim might seem to require a detailed engagement with the relevant science, yet in a striking admission early on, Nagel reveals that his book “is just the opinion of a layman who reads widely in the literature that explains contemporary science to the nonspecialist.” And a recurring objection to what he learned from his layman’s reading of popular science writing is that much science “flies in the face of common sense,” that it is inconsistent with “evident facts about ourselves, that it “require[s] us to deny the obvious,” and so on.
The authors add dryly:
This style of argument does not, alas, have a promising history.
. . and then the reviewers make a point that resonates deeply with me: materialism and naturalism need no a priori justification, but are justified by their fruits:
Happily, Nagel does not attempt to repudiate the Copernican revolution in astronomy, despite its hostility to common sense. But he displays none of the same humility when it comes to his preferred claims of common sense—the kind of humility that nearly 400 years of nonevident yet true scientific discoveries should engender. Are we really supposed to abandon a massively successful scientific research program because Nagel finds some scientific claims hard to square with what he thinks is obvious and “undeniable,” such as his confidence that his “clearest moral…reasonings are objectively valid”?
In support of his skepticism, Nagel writes: “The world is an astonishing place, and the idea that we have in our possession the basic tools needed to understand it is no more credible now than it was in Aristotle’s day.” This seems to us perhaps the most startling sentence in all of Mind and Cosmos. Epistemic humility—the recognition that we could be wrong—is a virtue in science as it is in daily life, but surely we have some reason for thinking, some four centuries after the start of the scientific revolution, that Aristotle was on the wrong track and that we are not, or at least not yet. Our reasons for thinking this are obvious and uncontroversial: mechanistic explanations and an abandonment of supernatural causality proved enormously fruitful in expanding our ability to predict and control the world around us. The fruits of the scientific revolution, though at odds with common sense, allow us to send probes to Mars and to understand why washing our hands prevents the spread of disease. We may, of course, be wrong in having abandoned teleology and the supernatural as our primary tools for understanding and explaining the natural world, but the fact that “common sense” conflicts with a layman’s reading of popular science writing is not a good reason for thinking so.
I can’t resist adding this, though (and I do realize I’m quoting a lot of the piece), for the authors of the review have done a good job:
Philosophical naturalists often appeal to the metaphor of “Neurath’s Boat,” named after the philosopher who developed it. Our situation as inquirers trying to understand the world around us, according to Neurath, is like that of sailors who must rebuild their ship while at sea. These sailors do not have the option of abandoning the ship and rebuilding a new one from scratch. They must, instead, try to rebuild it piecemeal, all the time staying afloat on other parts of the ship on which they continue to depend. In epistemological terms, we are also “at sea”: we cannot abandon all the knowledge about the world we have acquired from the sciences and then ask what we really know or what is really rational. The sciences that have worked so well for us are precisely our benchmark for what we know and what is rational; they’re the things that are keeping us “afloat.” Extending this metaphor, we can say that Nagel is the sailor who says, “I know the ideal form a ship should take—it is intuitively obvious, I am confident in it—so let us jump into the ocean and start building it from scratch.”
I won’t dissect the rest of the review, or Nagel’s arguments as expressed therein, but let me add that Nagel fleshes out Plantinga’s arguments by claiming that there are indeed moral truths (if you object to Sam Harris, you must also object to Nagel), and that natural selection was impotent at giving us the ability to see them. Where do they come from, then? Nagel apparently has no idea.
I don’t think there are objective moral truths, though morality seems to be grounded on certain principles that most humans take to be true (i.e. increasing well-being is good), and it’s indubitably true that “morality” is not completely coded in our genes anyway. How could it be if those so-called “truths” have changed so drastically in the last few centuries?
In the end, Nagel calls for a revival of teleological thinking. He’s not a believer, so I’m not sure exactly what the “driving force” of biological diversity is supposed to be. Nor am I sure what has happened to Nagel, for he’s throwing over one of the best-established theories in science for some teleological process that he can only intuit. He appears to have caught some virus from Jerry Fodor, and if other philosophers don’t condemn Nagel’s mushy thinking, I’ll have lost a lot of respect for philosophy. For crying out loud, any average biologist can think harder about this problem than the vaunted philosopher Nagel!
Finally, here is Leiter and Weisberg’s summary of the book:
We conclude with a comment about truth in advertising. Nagel’s arguments against reductionism are quixotic, and his arguments against naturalism are unconvincing. He aspires to develop “rival alternative conceptions” to what he calls the materialist neo-Darwinian worldview, yet he never clearly articulates this rival conception, nor does he give us any reason to think that “the present right-thinking consensus will come to seem laughable in a generation or two.” Mind and Cosmos is certainly an apt title for Nagel’s philosophical meditations, but his subtitle—”Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False”—is highly misleading. Nagel, by his own admission, relies only on popular science writing and brings to bear idiosyncratic and often outdated views about a whole host of issues, from the objectivity of moral truth to the nature of explanation. No one could possibly think he has shown that a massively successful scientific research program like the one inspired by Darwin’s theory of evolution by natural selection “is almost certainly false.” The subtitle seems intended to market the book to evolution deniers, intelligent-design acolytes, religious fanatics and others who are not really interested in the substantive scientific and philosophical issues. Even a philosopher sympathetic to Nagel’s worries about the naturalistic worldview would not claim this volume comes close to living up to that subtitle. Its only effect will be to make the book an instrument of mischief.
Indeed: the Discovery Institute will be all over this one like ugly on a frog.