|publisher:||Oxford University Press|
|tags:||Science & Technology|
“WHAT'S PAST IS PROLOGUE,” a line dear to our American identification with endless progress, is — like so much apparent proverbial wisdom — actually a quote from William Shakespeare. Antonio speaks it to Sebastian early in Act II of The Tempest, when the context happens to be criminal. In American usage, the context is more often Whiggishly historical. Thomas Nagel’s new book is an essay in the philosophy of science, but Whig historiography bears rather heavily upon it.
Whig historiography is so named for the British political movement that, between the late 17th and the mid-19th century, successfully established the superiority of parliament over the monarchy. The Whigs saw all of the British past as a prologue to this great achievement. In its high imperial variant, Whig historiography saw the British Empire as glorious confirmation of the ever more evident truth that history had come to a providential culmination in London.
Meanwhile, Whiggery’s American variant took the entire European past as prologue to the Great American Experiment. President Woodrow Wilson may have been the prophet who first brought the American revelation to a world audience, but that revelation seemed most nearly to come to fulfillment in the half-century after World War II. By the 1990s, Americans complacently accepted their country’s division of the entire planet into a set of six interlocking military commands as Englishmen had accepted the sun’s never setting on the British Empire. Yes, CENTCOM, AFRICOM, PACOM, and the others did serve American national defense and national prosperity, but the world was also, on balance, much the better for them being there. History had led the world beyond London to the “Washington Consensus,” and the worldly-wise would run to meet this culmination.
Britain’s Whiggish self-confidence collapsed in the wake of World War I. A century later, the comparable American self-confidence is collapsing as we speak, for reasons that scarcely need to be rehearsed here. Yet there is one arena of modern life in which a Whiggish faith that the present is a grand and final culmination of the past lives on, and that area is science. The Whiggish history of science understands not just all past study of nature, but all of human thought to have come, in modern science, to a culmination whose future entails no replacement, only modifications within the existing rules of operation. That this must be so is an implicit moral commitment that, in the writings of some scientists, becomes quite explicit. But the terminal validity of science cannot be a scientific conclusion, since — although science makes many valid predictions — no science exists that has the ability to predict the future of science.
Nagel’s subject in Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False is the human mind, taken to be so important a part of nature that no science unable to fully explain it can claim to have a methodology able, in the very long run, to understand nature. He makes clear in two opening chapters that he takes nature — the “Cosmos” of his title — to be a singular thing, and that he does not wish to suppose mind as in any way a supernatural or extranatural reality located somehow above or outside it. He then turns his attention in successive chapters to (quoting their titles) “Consciousness,” “Cognition,” and “Value.” His overriding question is: will the present methodology of science, in which only physical evidence counts as evidence, finally prove equal to explaining these three, or will it fail?
That question seems simple enough, but against a backdrop of Whiggish certainty about the scientific method, it is little less than inflammatory. Writing of science and human consciousness in 1970, Jacques Monod, a Nobel Laureate in Biology, asserted that a moral commitment “to take consciousness as being limited to…physical mechanism” must precede rather than follow investigation. It must be not the result of research but rather a premise guiding research:
It is plain that to make the postulate of objectivity a condition for true knowledge constitutes an ethical choice and not a knowledge judgment inasmuch as according to the postulate itself, there can be no “true” knowledge before this arbitrary choice. The postulate of objectivity, in order to establish a norm for knowledge, defines a value which is objective knowledge itself. To accept the postulate of objectivity then is to articulate the basic proposition of an ethics: the ethics of knowledge. (Le hasard et la nécessité, my translation.)
Nagel is no less committed than Monod to an ethics of knowledge as he considers mind and cosmos, nor is he any less committed to objectivity. Yet what Nagel proposes in his calmly provocative new book is a radical revision of what objectivity truly calls for. In order to propose such a revision in the face of an intellectual consensus far more massively and far more internationally rooted than “the Washington Consensus” of the 1990s ever was, he has had to first confront the Whiggish confidence that where science is now, methodologically, where human knowing must ever be. Thus, early in his book, he 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.
His point is not to argue for Aristotelianism, though one reviewer has read him that way. His point is rather to argue that a future physics may well differ as much from today’s physics as today’s does from Aristotle’s — which is to say as much as science differs from natural history or philosophy from religion. No scientist would deny this in principle, but Nagel finds that many ignore even the bare possibility in practice. If his book achieves nothing else, it may succeed in making the possibility a bit harder to ignore.
Concluding a generally critical discussion of Mind and Cosmos in The New York Review of Books, H. Allen Orr grants this one point of Nagel’s. “None of this,” he concedes,
is to suggest that evolutionary biology will not, someday, change radically. Of course it might; any science might. Nor is it to suggest that materialism represents some final unassailable view and that teleology or, for that mater, theism will inevitably be spoken of in the past tense by many scientists. It is to say that the way to any such alternative view will have to acknowledge the full powers of present science. I cannot conclude that Mind and Cosmos does this.
This is no ringing endorsement. Au contraire, and yet were I Nagel, I would rejoice more over this concluding paragraph than I would grieve over all that precedes it in Orr’s review. Nagel has put his landing party ashore.
The reviews that this short, immaculately written, unfailingly clear but dense little book continues to attract are a phenomenon as interesting as the book itself. Most of them have been negative, usually pointing out, just as Orr does, one aspect or another of present science that Nagel has failed to acknowledge adequately. But one might well ask why, then, review the book? Why be provoked? Nagel admits at the outset that he has only an attentive general reader’s knowledge of the normal science he calls into question. Why bother to engage such an amateur when he has the effrontery to call upon science to produce a new form of post-scientific understanding about which he can only offer, for all his meticulous manner, a wild surmise or two?
Nagel’s suggestions are scarcely modest ones. On one of the final pages of the book, he offers the following jaw-dropping summary of his views on the relationship between life and moral value — that is, the relationship of life to good-over-evil, to right-over-wrong. “In brief,” he writes, “value is not just an accidental side effect of life; rather, there is life because life is a necessary condition of value.” This is prima facie about as floridly anti-Darwinian a hypothesis as one could hope to find in contemporary secular literature. But he goes on. In the very next sentence, we read: “This is a revision of the Darwinian picture rather than an outright denial of it.” True, it is not a denial of “the Darwinian picture,” whose general validity Nagel repeatedly pauses to endorse, but it is a fairly astonishing proposal for revision.
Nagel believes that nature, properly understood, has its own purpose. As an atheist, he does not believe in a god who has made the world for some divine purpose, but he does see nature as striving toward a natural good of its own. He sees “a cosmic predisposition to the formation of life, consciousness, and the value that is inseparable from them.” In the margin of my copy, opposite his “cosmic predisposition,” I wrote: “May the Force be with you”. The mood of this work could not be more remote than it is from the mood of Star Wars, yet the world it imagines does seem at times to be another world, not the one this reader of science packaged for the layman has been taught to understand as our own.
Nagel himself characterizes his work at one point as “extravagantly speculative” and at another as “complete fantasy.” Imagining the laws of the natural teleology just mentioned, he writes that they “would be laws of the self-organization of matter, essentially — or of whatever is more basic than matter” (emphasis added). One might expect the kind of reviewers who have been engaging this book to pass over it in silence, but they have not done so. The collective response to the book, a response still in progress, recently merited a front-page story in the “Science Times” section of The New York Times. How do we account for this?
Nagel commands attention, I suspect, primarily for one of his arguments in particular, to which I will turn in a moment, but secondarily because of the relentlessly rational way in which he confronts what is for many, as for Monod, a moral commitment — a kind of faith — as well as a working methodology. Though never truly ad hominem, his work may put many who have made this commitment rather personally on edge. He writes in perhaps his nearest approach to ad hominem writing:
I find the confidence among the scientific establishment that the whole scenario will yield to a purely chemical explanation hard to understand, except as a manifestation of an axiomatic commitment to reductive materialism.
And in a footnote to this sentence, he quotes Richard Lewontin as an example of axiomatic, a priori commitment:
It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world, but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counter-intuitive, no matter how mystifying to the uninitiated. Moreover, that materialism is absolute, for we cannot allow a Divine Foot in the door.
Nagel finds theism intellectually unacceptable and emotionally repellent. His is thus no “Divine Foot” in the door of committed, absolute materialism, but precisely as a human foot in that door, his foot may be exasperatingly hard to ignore.
Nagel has two opening questions to put to the “reductionist neo-Darwinian account of the origin and evolution of life”:
First, given what is known about the chemical basis of biology and genetics, what is the likelihood that self-reproducing life forms should have come into existence spontaneously on the early earth, solely through the operation of the laws of physics and chemistry?
This spontaneous coming-into-existence is the event neatly captured in Monod’s 1970 title Le hasard et la nécessité (Chance and Necessity). The life-initiating event — the accidental formation from inorganic matter of a self-replicating mechanism — was an incalculably improbable occurrence. This is the “Chance” of Monod’s title. But because what then happened only had to happen once — because what then came into being could not go out of being, for it was self-replicating — evolution was set irreversibly in motion as a parade led by nobody. Such was the “Necessity” of Monod’s title. If the Higgs boson is the “god particle” for the physics of the Big Bang, this was the “god event” for evolutionary biology.
Yet did this god event ever really happen? To this day, it remains no more than a postulate. Many find it a deeply satisfying postulate. Some profess to find it thrilling. Nagel seems to finds it neither. Quite unpersuaded that it happened in a way that could sustain all that has been hung upon it, he is like a mourner at a wedding who doubts that the bride and groom are actually in attendance.
And then there is his second question:
The second question is about the sources of variation in the evolutionary process that was set in motion once life began: In the available geological time since the first life forms appeared on earth, what is the likelihood that, as a result of physical accident, a sequence of viable genetic mutations should have occurred that was sufficient to permit natural selection to produce the organisms that actually exist?
With this question, though it is significantly more available to investigation than the first, Nagel is like an embarrassing guest at an elderly couple’s diamond wedding anniversary. All the children, grandchildren, and great-grandchildren are gathered round, but this presumed friend of the family professes doubt that the old couple could have produced so large a family even in the 75 years since their wedding. He questions, in a word, the legitimacy of the family — an embarrassing guest indeed.
Reviewers have energetically turned back Nagel’s challenge on both of these two points, which, of course, I have done no more than mention here. Challenging his succeeding chapter, “Consciousness,” they have adduced contemporary neurobiological work on the evolution of consciousness, and this work is undeniably impressive. (While reading Mind and Cosmos, I attended much of a National Academy of Sciences conference at the University of California, Irvine, entitled “In the Light of Evolution VII: The Human Mental Machinery,” which functioned as a serial rebuttal.) Other reviewers have dismissed out of hand Nagel’s speculatively postulated “panpsychic monism” as the vehicle for an immanent, entirely natural teleology.
Yet what scarcely any reviewer seems to have engaged is what to me is the inherently most disruptive argument in the book: that if evolutionary accounts of the origin of human reason are correct without significant revision, then reason cannot be relied upon. We are aware that our eyes can play tricks on us, that we have more of a sweet tooth than is good for us, that our sex drive seems to have a “mind” of its own, and so forth. An understanding of our evolutionary history as a species can go far in teaching us why we have these tendencies, and why, under current circumstances, they may no longer be as adaptive as they once were. A philosopher like Daniel Dennett takes this position toward religion as well. Religion is an understandable proclivity, he argues, given the history of the species — a proclivity arguably adaptive in past human environments, however maladaptive in the current environment.
But what of reason itself? What of our very capacity to establish whether it is true or not that our evolutionary history has conferred upon us a favorable reaction to the sweet taste of a banana? Nagel observes:
[W]henever we take such a reasonable detached attitude toward our innate dispositions, we are implicitly engaged in a form of thought to which we do not at the same time take that detached attitude. When we rely on systems of measurement to correct perception, or probability calculations to correct intuitive expectations, or moral or prudential reasoning to correct instinctive impulses, we take ourselves to be responding to systematic reasons which in themselves justify our conclusions, and which do not get their authority from their biological origins. They could not be backed up in that way […]
It is not possible to think, “Reliance on my reason, including my reliance on this very judgment, is reasonable because it is consistent with its having an evolutionary explanation.” Therefore any evolutionary account of the place of reason presupposes reason’s validity and cannot confirm it without circularity.
It is this circularity — this failure to account for reason without depending upon reason — that leads Nagel to suspect some deep inadequacy in the entire approach to the subject in evolutionary theory. If reason itself is taken to have evolved not for the pursuit of truth but, like all our other capacities, for the pursuit of reproductive success, then our irresistible conviction that A is scientifically established and true, while B is without scientific warrant and thus false, may be no more trustworthy than our craving for sweets. If we do not take it thus, we contradict ourselves. If we do take it thus, we cease to trust it, and all theory comes crashing down.
In popular thought, it is technological success that seems most to confirm any theory. But technological success does not easily settle this question. The Romans built the Pantheon while holding to a geocentric cosmology and a mathematics that lacked the zero. For that matter, ants build architecturally marvelous anthills using only the instinctive skills that evolution has endowed them with. Their technology is pretty impressive, but do we infer from this that they can distinguish true from false? Our technology works impressively well, too. At least until now, it has spectacularly enhanced our reproductive success, spreading our kind around the entire planet. But what of the supposed knowledge that enables it? May it not still be illusory, just a spandrel, just a byproduct of our evolutionary history?
Nagel is a professed scientific realist. He does not put scientific knowledge in scare quotes. He believes that reason is reliable and that science does engage reality. But when an account of the origin of reason that links it entirely to reproductive success has this self-subversive corollary, he chooses to trust reason and question the account rather than trust the account and question reason.
Here, for this reviewer, is the core challenge, the core disturbance, of this challenging and intentionally disruptive work. Mind and Cosmos, which has been taken as an oblique defense of creationism, is actually a defense of reason. Yet it is also a fabulous effort of the imagination. The place of imagination, of fantasy, even of dream-life in the history of human thought is a large one. Nagel admits that he is not a scientist, but it would call for imagination and not just analysis for a scientist in any given field to begin thinking past contemporary science as a whole toward the contours of what might someday succeed it. Unless one is a scientific Whig, one must strongly suspect that something someday will indeed succeed it. Nagel’s Mind and Cosmos does not build a road to that destination, but it is much to have gestured toward a gap in the hills through which a road might someday run.