I. ACCORDING TO a semi-established consensus among the intellectual elite in the West, there is no such person as God or any other supernatural being. Life on our planet arose by way of ill-understood but completely naturalistic processes involving only the working of natural law. Given life, natural selection has taken over, and produced all the enormous variety that we find in the living world. Human beings, like the rest of the world, are material objects through and through; they have no soul or ego or self of any immaterial sort. At bottom, what there is in our world are the elementary particles described in physics, together with things composed of these particles.
I say that this is a semi-established consensus, but of course there are some people, scientists and others, who disagree. There are also agnostics, who hold no opinion one way or the other on one or another of the above theses. And there are variations on the above themes, and also halfway houses of one sort or another. Still, by and large those are the views of academics and intellectuals in America now. Call this constellation of views scientific naturalism—or don’t call it that, since there is nothing particularly scientific about it, except that those who champion it tend to wrap themselves in science like a politician in the flag. By any name, however, we could call it the orthodoxy of the academy—or if not the orthodoxy, certainly the majority opinion.
The eminent philosopher Thomas Nagel would call it something else: an idol of the academic tribe, perhaps, or a sacred cow: “I find this view antecedently unbelievable—a heroic triumph of ideological theory over common sense. … I would be willing to bet that the present right-thinking consensus will come to seem laughable in a generation or two.” Nagel is an atheist; even so, however, he does not accept the above consensus, which he calls materialist naturalism; far from it. His important new book is a brief but powerful assault on materialist naturalism.
NAGEL IS NOT AFRAID to take unpopular positions, and he does not seem to mind the obloquy that goes with that territory. “In the present climate of a dominant scientific naturalism,” he writes, “heavily dependent on speculative Darwinian explanations of practically everything, and armed to the teeth against attacks from religion, I have thought it useful to speculate about possible alternatives. Above all, I would like to extend the boundaries of what is not regarded as unthinkable, in light of how little we really understand about the world.” Nagel has endorsed the negative conclusions of the much-maligned Intelligent Design movement, and he has defended it from the charge that it is inherently unscientific. In 2009 he even went so far as to recommend Stephen Meyer’s book Signature in the Cell: DNA and the Evidence for Intelligent Design, a flagship declaration of Intelligent Design, as a book of the year. For that piece of blasphemy Nagel paid the predictable price; he was said to be arrogant, dangerous to children, a disgrace, hypocritical, ignorant, mind-polluting, reprehensible, stupid, unscientific, and in general a less than wholly upstanding citizen of the republic of letters.
His new book will probably call forth similar denunciations: except for atheism, Nagel rejects nearly every contention of materialist naturalism. Mind and Cosmosrejects, first, the claim that life has come to be just by the workings of the laws of physics and chemistry. As Nagel points out, this is extremely improbable, at least given current evidence: no one has suggested any reasonably plausible process whereby this could have happened. As Nagel remarks, “It is an assumption governing the scientific project rather than a well-confirmed scientific hypothesis.”
The second plank of materialist naturalism that Nagel rejects is the idea that, once life was established on our planet, all the enormous variety of contemporary life came to be by way of the processes evolutionary science tells us about: natural selection operating on genetic mutation, but also genetic drift, and perhaps other processes as well. These processes, moreover, are unguided: neither God nor any other being has directed or orchestrated them. Nagel seems a bit less doubtful of this plank than of the first; but still he thinks it incredible that the fantastic diversity of life, including we human beings, should have come to be in this way: “the more details we learn about the chemical basis of life and the intricacy of the genetic code, the more unbelievable the standard historical account becomes.” Nagel supports the commonsense view that the probability of this happening in the time available is extremely low, and he believes that nothing like sufficient evidence to overturn this verdict has been produced.
So far Nagel seems to me to be right on target. The probability, with respect to our current evidence, that life has somehow come to be from non-life just by the working of the laws of physics and chemistry is vanishingly small. And given the existence of a primitive life form, the probability that all the current variety of life should have come to be by unguided evolution, while perhaps not quite as small, is nevertheless minuscule. These two conceptions of materialist naturalism are very likely false.
But, someone will say, the improbable happens all the time. It is not at all improbable that something improbable should happen. Consider an example. You play a rubber of bridge involving, say, five deals. The probability that the cards should fall just as they do for those five deals is tiny—something like one out of ten to the 140th power. Still, they did. Right. It happened. The improbable does indeed happen. In any fair lottery, each ticket is unlikely to win; but it is certain that one of them will win, and so it is certain that something improbable will happen. But how is this relevant in the present context? In a fit of unbridled optimism, I claim that I will win the Nobel Prize in chemistry. You quite sensibly point out that this is extremely unlikely, given that I have never studied chemistry and know nothing about the subject. Could I defend my belief by pointing out that the improbable regularly happens? Of course not: you cannot sensibly hold a belief that is improbable with respect to all of your evidence.
NAGEL GOES ON: he thinks it is especially improbable that consciousness and reason should come to be if materialist naturalism is true. “Consciousness is the most conspicuous obstacle to a comprehensive naturalism that relies only on the resources of physical science.” Why so? Nagel’s point seems to be that the physical sciences—physics, chemistry, biology, neurology—cannot explain or account for the fact that we human beings and presumably some other animals are conscious. Physical science can explain the tides, and why birds have hollow bones, and why the sky is blue; but it cannot explain consciousness. Physical science can perhaps demonstrate correlations between physical conditions of one sort or another and conscious states of one sort or another; but of course this is not to explain consciousness. Correlation is not explanation. As Nagel puts it, “The appearance of animal consciousness is evidently the result of biological evolution, but this well-supported empirical fact is not yet an explanation—it does not provide understanding, or enable us to see why the result was to be expected or how it came about.”
Nagel next turns his attention to belief and cognition: “the problem that I want to take up now concerns mental functions such as thought, reasoning, and evaluation that are limited to humans, though their beginnings may be found in a few other species.” We human beings and perhaps some other animals are not merely conscious, we also hold beliefs, many of which are in fact true. It is one thing to feel pain; it is quite another to believe, say, that pain can be a useful signal of dysfunction. According to Nagel, materialist naturalism has great difficulty with consciousness, but it has even greater difficulty with cognition. He thinks it monumentally unlikely that unguided natural selection should have “generated creatures with the capacity to discover by reason the truth about a reality that extends vastly beyond the initial appearances.” He is thinking in particular of science itself.
Natural selection is interested in behavior, not in the truth of belief, except as that latter is related to behavior. So concede for the moment that natural selection might perhaps be expected to produce creatures with cognitive faculties that are reliable when it comes to beliefs about the physical environment: beliefs, for example, about the presence of predators, or food, or potential mates. But what about beliefs that go far beyond anything with survival value? What about physics, or neurology, or molecular biology, or evolutionary theory? What is the probability, given materialist naturalism, that our cognitive faculties should be reliable in such areas? It is very small indeed. It follows—in a wonderful irony—that a materialistic naturalist should be skeptical about science, or at any rate about those parts of it far removed from everyday life.
This certainly seems right, and perhaps we can go even further. Perhaps it is not initially implausible to think that unguided natural selection could have produced creatures with cognitive faculties who are reliable about matters relevant to survival and reproduction. But what about metaphysical beliefs, such as theism, or determinism, or materialism, or atheism? Such beliefs have little bearing on behavior related to survival and reproduction, and unguided natural selection couldn’t care less about them or their truth-value. After all, it is only the occasional member of the Young Humanist Society whose reproductive prospects are enhanced by accepting atheism. Given materialist naturalism, the probability that my cognitive faculties are reliable with respect to metaphysical beliefs would be low. So take any metaphysical belief I have: the probability that it is true, given materialist naturalism, cannot be much above .5. But of course materialist naturalism is itself a metaphysical belief. So the materialistic naturalist should think the probability of materialist naturalism is about .5. But that means that she cannot sensibly believe her own doctrine. If she believes it, she shouldn’t believe it. In this way materialist naturalism is self-defeating.
II. THE NEGATIVE CASE that Nagel makes against materialist naturalism seems to me to be strong and persuasive. I do have the occasional reservation. Most materialists apparently believe that mental states are caused by physical states. According to Nagel, however, the materialistic naturalist cannot stop there. Why not? Because the idea that there is such a causal connection between the physical and the mental doesn’t really explain the occurrence of the mental in a physical world. It doesn’t make the mental intelligible. It doesn’t show that the existence of the mental is probable, given our physical world.
Some materialists, however, seek to evade this difficulty by suggesting that there is some sort of logical connection between physical states and mental states. It is a logically necessary truth, they say, that when a given physical state occurs, a certain mental state also occurs. If this is true, then the existence of the mental is certainly probable, given our physical world; indeed, its existence is necessary. Nagel himself suggests that there are such necessary connections. So wouldn’t that be enough to make intelligible the occurrence of the mental in our physical world?
I suspect that his answer would be no. Perhaps the reason would be that we cannot just see these alleged necessities, in the way we can just see that 2+1=3. These postulated necessary connections are not self-evident to us. And the existence of the mental would be intelligible only if those connections were self-evident. But isn’t this a bit too strong? Why think that the mental is intelligible, understandable, only if there are self-evident necessary connections between the physical and the mental? Doesn’t that require too much? And if intelligibility does require that sort of connection between the physical and the mental, why think the world is intelligible in that extremely strong sense?
Now you might think someone with Nagel’s views would be sympathetic to theism, the belief that there is such a person as the God of the Abrahamic religions. Materialist naturalism, says Nagel, cannot account for the appearance of life, or the variety we find in the living world, or consciousness, or cognition, or mind—but theism has no problem accounting for any of these. As for life, God himself is living, and in one way or another has created the biological life to be found on Earth (and perhaps elsewhere as well). As for the diversity of life: God has brought that about, whether through a guided process of evolution or in some other way. As for consciousness, again theism has no problem: according to theism the fundamental and basic reality is God, who is conscious. And what about the existence of creatures with cognition and reason, creatures who, like us, are capable of scientific investigation of our world? Well, according to theism, God has created us human beings in his image; part of being in the image of God (Aquinas thought it the most important part) is being able to know something about ourselves and our world and God himself, just as God does. Hence theism implies that the world is indeed intelligible to us, even if not quite intelligible in Nagel’s glorified sense. Indeed, modern empirical science was nurtured in the womb of Christian theism, which implies that there is a certain match or fit between the world and our cognitive faculties.
Given theism, there is no surprise at all that there should be creatures like us who are capable of atomic physics, relativity theory, quantum mechanics, and the like. Materialist naturalism, on the other hand, as Nagel points out, has great difficulty accounting for the existence of such creatures. For this and other reasons, theism is vastly more welcoming to science than materialist naturalism. So theism would seem to be a natural alternative to the materialist naturalism Nagel rejects: it has virtues where the latter has vices, and we might therefore expect Nagel, at least on these grounds, to be sympathetic to theism.
SADLY ENOUGH (at least for me), Nagel rejects theism. “I confess to an ungrounded assumption of my own, in not finding it possible to regard the design alternative [i.e., theism] as a real option. I lack the sensus divinitatis that enables—indeed, compels so many people to see in the world the expression of divine purpose.” But it isn’t just that Nagel is more or less neutral about theism but lacks that sensus divinitatis. In The Last Word, which appeared in 1997, he offered a candid account of his philosophical inclinations:
I am talking about something much deeper—namely, the fear of religion itself. I speak from experience, being strongly subject to this fear myself: I want atheism to be true and am made uneasy by the fact that some of the most intelligent and well-informed people I know are religious believers…. It isn’t just that I don’t believe in God and, naturally, hope that I’m right in my belief. It’s that I hope there is no God! I don’t want there to be a God; I don’t want the universe to be like that.
Here we have discomfort and distress at the thought that there might be such a being as God; but this discomfort seems more emotional than philosophical or rational.
So is there a strictly philosophical problem with theism, according to Nagel? As far as I can see, the main substantive objection that he offers is an appeal to that notion of unity. A successful worldview will see the world as intelligible; and intelligibility, as Nagel conceives it, involves a high degree of unity. The world is intelligible only if there are no fundamental breaks in it, only if it contains no fundamentally different kinds of things. Descartes, that great dualist, thought that the world displays two quite different sorts of things: matter and mind, neither reducible to the other. Nagel rejects this dualism: his reason is just that such dualism fails to secure the unity necessary for the world’s being intelligible.
Yet is there any reason to think that the world really is intelligible in this very strong sense—any good reason to think that there is fundamentally just one kind of thing, with everything being an example of that kind, or reducible to things that are? Here three considerations seem to be necessary. First, we need to know more about this requirement: what is it to say that fundamentally there is just one kind of thing? It is not obvious how this is to be understood. Aren’t there many different sorts of things: houses, horses, hawks, and handsaws? Well, perhaps they are not fundamentallydifferent. But what does “fundamentally” mean here? Is the idea that the world is intelligible only if there is some important property that houses, horses, hawks, and handsaws all share? What kind of property?
Second, how much plausibility is there to the claim that this sort of unity really is required for intelligibility? Clearly we cannot claim that Descartes’s dualism is literally unintelligible—after all, even if you reject it, you can understand it. (How else could you reject it?) Is it really true that the world is more intelligible, in some important sense of “intelligible,” if it does not contain two or more fundamentally different kinds of things? I see little reason to think so.
And third, suppose we concede that the world is genuinely intelligible only if it displays this sort of monistic unity: why should we think that the world really does display such a unity? We might hope that the world would display such unity, but is there any reason to think the world will cooperate? Suppose intelligibility requires that kind of unity: why should we think our world is intelligible in that sense? Is it reasonable to say to a theist, “Well, if theism were true, there would be two quite different sorts of things: God on the one hand, and the creatures he has created on the other. But that cannot really be true: for if it were, the world would not display the sort of unity required for intelligibility”? Won’t the theist be quite properly content to forgo that sort of intelligibility?
III. I COME FINALLY to Nagel’s positive thesis. Materialist naturalism, he shows, is false, but what does he propose to put in its place? Here he is a little diffident. He thinks that it may take centuries to work out a satisfactory alternative to materialist naturalism (given that theism is not acceptable); he is content to propose a suggestive sketch. He does so in a spirit of modesty: “I am certain that my own attempt to explore alternatives is far too unimaginative. An understanding of the universe as basically prone to generate life and mind will probably require a much more radical departure from the familiar forms of naturalistic explanation than I am at present able to conceive.”
There are two main elements to Nagel’s sketch. There is panpsychism, or the idea that there is mind, or proto-mind, or something like mind, all the way down. In this view, mind never emerges in the universe: it is present from the start, in that even the most elementary particles display some kind of mindedness. The thought is not, of course, that elementary particles are able to do mathematical calculations, or that they are self-conscious; but they do enjoy some kind of mentality. In this way Nagel proposes to avoid the lack of intelligibility he finds in dualism.
Of course someone might wonder how much of a gain there is, from the point of view of unity, in rejecting two fundamentally different kinds of objects in favor of two fundamentally different kinds of properties. And as Nagel recognizes, there is still a problem for him about the existence of minds like ours, minds capable of understanding a fair amount about the universe. We can see (to some degree, anyway) how more complex material objects can be built out of simpler ones: ordinary physical objects are composed of molecules, which are composed of atoms, which are composed of electrons and quarks (at this point things get less than totally clear). But we haven’t the faintest idea how a being with a mind like ours can be composed of or constructed out of smaller entities that have some kind of mindedness. How do those elementary minds get combined into a less than elementary mind?
The second element of Nagel’s sketch is what we can call natural teleology.His idea seems to be something like this. At each stage in the development of our universe (perhaps we can think of that development as starting with the big bang), there are several different possibilities as to what will happen next. Some of these possibilities are steps on the way toward the existence of creatures with minds like ours; others are not. According to Nagel’s natural teleology, there is a sort of intrinsic bias in the universe toward those possibilities that lead to minds. Or perhaps there was an intrinsic bias in the universe toward the sorts of initial conditions that would lead to the existence of minds like ours. Nagel does not elaborate or develop these suggestions. Still, he is not to be criticized for this: he is probably right in believing that it will take a lot of thought and a long time to develop these suggestions into a truly viable alternative to both materialist naturalism and theism.
I SAID ABOVE THAT Nagel applauds the negative side of Intelligent Design but is doubtful about the positive part; and I find myself in much the same position with respect to Mind and Cosmos. I applaud his formidable attack on materialist naturalism; I am dubious about panpsychism and natural teleology. As Nagel sees, mind could not arise in our world if materialist naturalism were true—but how does it help to suppose that elementary particles in some sense have minds? How does that make it intelligible that there should be creatures capable of physics and philosophy? And of poetry, art, and music?
As for natural teleology: does it really make sense to suppose that the world in itself, without the presence of God, should be doing something we could sensibly call “aiming at” some states of affairs rather than others—that it has as a goal the actuality of some states of affairs as opposed to others? Here the problem isn’t just that this seems fantastic; it does not even make clear sense. A teleological explanation of a state of affairs will refer to some being that aims at this state of affairs and acts in such a way as to bring it about. But a world without God does not aim at states of affairs or anything else. How, then, can we think of this alleged natural teleology?
When it comes to accommodating life and mind, theism seems to do better. According to theism, mind is fundamental in the universe: God himself is the premier person and the premier mind; and he has always existed, and indeed exists necessarily. God could have desired that there be creatures with whom he could be in fellowship. Hence he could have created finite persons in his own image: creatures capable of love, of knowing something about themselves and their world, of science, literature, poetry, music, art, and all the rest. Given theism, this makes eminently good sense. As Nagel points out, the same cannot be said about materialist naturalism. But do panpsychism and natural teleology do much better?
Nagel’s rejection of theism does not seem to be fundamentally philosophical. My guess is this antipathy to theism is rather widely shared. Theism severely limits human autonomy. According to theism, we human beings are also at best very junior partners in the world of mind. We are not autonomous, not a law unto ourselves; we are completely dependent upon God for our being and even for our next breath. Still further, some will find in theism a sort of intolerable invasion of privacy: God knows my every thought, and indeed knows what I will think before I think it. Perhaps hints of this discomfort may be found even in the Bible itself:
Before a word is on my tongue, you know it completely, oh Lord….
Where can I go from your Spirit?
Where can I flee from your presence?
If I go up to the heavens, you are there;
If I make my bed in Sheol, you are there.
This discomfort with theism is to some extent understandable, even to a theist. Still, if Nagel followed his own methodological prescriptions and requirements for sound philosophy, if he followed his own arguments wherever they lead, if he ignored his emotional antipathy to belief in God, then (or so I think) he would wind up a theist. But wherever he winds up, he has already performed an important service with his withering critical examination of some of the most common and oppressive dogmas of our age.
Alvin Plantinga is professor of philosophy emeritus at the University of Notre Dame and is the author, most recently, of Where the Conflict Really Lies: Science, Religion, and Naturalism (Oxford University Press). This article appeared in the December 6, 2012 issue of the magazine under the headline “A Secular Heresy.”