Consider this description of one of “America’s Byways”: “Traversing the lush hills and farmlands of southern Indiana, and paralleling the mighty Ohio River, this route marks a timeworn and history-rich corridor linking historic villages and farms through a picturesque landscape. Rock outcroppings, forested hills, caves, scenic waterways, and limestone bluffs will provide beautiful pictures for you to cherish.” The hills are said to be lush, the waterways to be scenic, and the landscape picturesque. Absent the human eye and aesthetic sensibility, however, the world is not divided into scenes, picturesque or otherwise. It is the imagined frame of a painting and the positioning of features within it that makes a scene picturesque. Likewise, what counts as a hill is not determined by the science of topography; it is a matter settled in different ways, in different cultures, according to different interests.

From such considerations has developed the belief that every category is an expression of our subjectivity and thus that the belief in an objective reality over and above our descriptions is an illusion. This view comes in a variety of forms, but it is reasonable to gather them under the title “antirealism.” At the other extreme stands the belief that reality is a single, uniform, and integrated totality constituted independently of human beings. The cosmos is intrinsically objective: Everything could in principle be described without reference to how it looks to any creature. This second position is that of an uncompromising scientific realism.

Whether realism must reject points of view is another matter. Indeed, following the philosopher Thomas Nagel, I shall be maintaining that the human perspective is ineliminable but also that it can be accommodated within a larger “transcendent” realism. Realism and antirealism, as such, however, cannot be reconciled because they are universalistic or, as each might say of the other, they are imperialistic.

In the advanced Western world, the philosophical debate between them”between the idea of a single, uniform world independent of any observer and the idea of numberless subjective worlds brought into being by the observer”has become increasingly divisive, not only among philosophers and other academics but within educated society more generally and indeed within the minds of individuals. Beyond the metaphysical, it involves ethical and political issues and reflects the broad opposition between “progressive liberals” and “social conservatives.”

Conservatives feel that ancient values reflecting enduring features of human nature are being ignored or attacked by nihilists who think that the sovereign value to which everything is subject is the ability to live as one chooses. Liberals feel that we must fashion new principles appropriate to an enlightened understanding of human development and that conservatives are trying to impose long-outmoded values rooted in ignorance and superstition. They reject the idea that there is an existing moral order antecedent to human thought and written into the structure of reality. Values are to be “made by humanity for humanity.”

The combination of subjectivism and progressivism has long been prominent within cultural, social, and historical studies, and it has received occasional endorsement and even encouragement from some “radical” philosophers who have acquired a following outside their own discipline. A prominent example was the late Richard Rorty, who was explicit about forging a link between antirealism and liberalism, and eager to challenge what he regarded as the superstition of realism, be it metaphysical or moral. In one of his last publications, An Ethics for Today , published two years ago, he makes the link explicit and asks: “Is the Church right that there is such a thing as the structure of human existence, which can serve as a moral reference point? Or, do we human beings have no moral obligations except helping one another satisfy our desires, thus achieving the greatest possible amount of happiness?”

Defining superstition as “the belief that any legitimate ideal must somehow be grounded in something already actual, something transcendent that sets this ideal before us,” he claims that “what the pope calls the structure of human existence is an example of such a transcendent entity”:

There is [however] nothing already in existence to which our moral convictions should try to correspond . . . . The answer to the question “Are some human desires bad?” is: No, but some desires do get in the way of our project of maximizing the overall satisfaction of desire . . . . There is no such thing as intrinsically evil desire.

It is significant that Rorty chose as his opponent Roman Catholicism and its present pope. He is right to view them as his principal opponents, since they represent one of the few contemporary institutional embodiments of the realist idea that morality is rooted in an objective moral order and the structure of reality.

The debates between conservatives and liberals about the status of morality have a rarely noted connection with contemporary disputes about evolutionary theories of human nature and with a wider disagreement between neo-Darwinians and advocates of the theistic idea that life in the cosmos bears evidence of being the product of mind.

In arguing about evolution and creation, there has been much confusion, often intentional, of scientific, theological, and philosophical ideas. Notwithstanding its name, “scientific naturalism” is a metaphysical doctrine rather than an empirical theory, maintaining beyond evidence that the origins of the universe, the world, and all life, past and present, are wholly explicable in terms of physical processes, including those of random genetic mutation, inheritance, and natural selection.

This is evidently incompatible with the religious belief that the universe was created and that human beings have a special spiritual nature. Scientific evidence of the evolution of species, and of patterns of common ancestry, is abundant but also independent of the issue of the source of the universe or of the emergence of life, and of the question of whether human beings have minds or souls. The ultimate origins of the universe and the materiality, or otherwise, of mankind belong to metaphysics. By the same token, therefore, the claims of “scientific naturalism””or “naturalism,” for short”have transcended those of strict science and entered the sphere of metaphysics.

If, by contrast, the cosmos is, as the theist argues, an ordered creation, then part of that order may constitute the basis for a natural law consisting of values and principles relating to the human good”as Rorty put it, a “structure of human existence, which can serve as a moral reference point.” These seemingly abstract speculations shape how we think about values and ethics.

What, then, of the credentials of naturalism? This composite of empirical theory and naturalistic metaphysics has been questioned on scientific and philosophical grounds quite apart from religious interests usually associated with such criticism. Some ask whether there has been enough time for the endlessly many modifications required to produce the diversity and complexity evident in the living world.

More profound is the issue of the origin of life. Since evolution presupposes biological reproduction, evolution itself cannot account for it, and efforts to explain it as a development out of primitive quasi-replication face the challenge that they either covertly reintroduce reproduction or otherwise fail to explain the transition from the one to the other.

Such issues have drawn a certain amount of attention from philosophers, but many are wary of being charged with giving sympathy to “intelligent designers” and other “enemies” of science. This indicates a level of intellectual bullying that needs to be named, and now it has been, by the distinguished American philosopher Thomas Nagel, in his new book Mind and Cosmos . In an earlier work, The Last Word , published in 1997, he defended the claims of reason against various forms of relativism and speculated that the defense of materialism is connected with “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.

This confessional prose style might suggest an unpredictable eccentric. In fact, Nagel is rightly regarded as among the most significant philosophers writing today and one of the most acute and consistent authors in contemporary analytical philosophy, whose work is imaginative and probing but also rigorous and methodical. There is a trajectory through his work that has brought him to his present position and might yet carry him beyond it.

The key to his philosophy is a contrast between two kinds of descriptions: the subjective and the objective . In his first book, The Possibility of Altruism , he identified two ways of thinking about producing good”the first self-directed (prudence), the second other-regarding (morality)”and tried to work out how these might be reconciled or absorbed into some third overarching view, an impartialism that comprehends both while somehow preserving their distinct claims. His second major book, The View from Nowhere , generalized the distinction of subjective and objective and applied it across a range of themes: the nature of the mind; its relation to body, thought, and reality; value and the meaning of life.

Nagel is a realist: He thinks there is a way things are, independent of how they may be apprehended. He is a scourge of postmodernists, relativists, and other antirealists who would replace the world with “worlds” of our making. But he is also committed to the reality of apprehending what is to be said of consciousness and reasoned thought, and of values as part of what is apprehended.

Nagel attempts to describe “what it is like” to see, hear, think, be, etc. The study of brains can only reveal objective facts, not the nature of subjective experiences. There is a gap between the object that is the brain and the subject that is the person, and the latter cannot be reduced either explanatorily or metaphysically to the former. Brain processes are subject to physical causation, but thoughts are subject to logic. In the same way, movements are subject to physical constraints, but actions are subject to moral ones. In each case, there is a reality that cannot be accounted for materially. Nagel is enough of a naturalist to think that consciousness, reasoning, and responsiveness to values depend upon bodily structures, but not enough of one to think that they simply are physical phenomena.

It is unsurprising that he doubts that neo-Darwinism can account for the existence of sentient, rational, and moral beings. He holds that these beings’ subjectivity inheres in their animality, which means that life itself must contain factors that can give rise to these nonmaterial powers. They cannot have arisen from merely physico-chemical interactions. Hence his subtitle: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False .

This presents a full-on challenge to the cultural and intellectual status quo. Nagel is aware that any questioning of evolutionary naturalism is deemed, among secularists, to be a kind of disloyalty: It offers hope and encouragement to the opposition, to the creationists, the intelligent designers, the religious philosophers, and all the rest of the God-and-morality types. He is willing to incur such criticism and to berate secularists for their bullying of intelligent design advocates and other rational skeptics, whom he applauds for their work in questioning the adequacy of evolutionary naturalism. But he is also likely amused at the thought of the disappointment that will result when religious readers discover that he remains opposed to a theistic explanation of mind, reason, and value.

Nagel identifies four responses to these phenomena: that of the scientific materialist, which he rejects as incapable of explaining them; that of the creationist (understood now in the broad sense of one who thinks that these are products of intentional design by a transcendent agent); that of declining to try to explain these phenomena, which he treats as a refusal to engage in the philosophical task of providing a comprehensive view of reality; and that of the non-materialist naturalist.

This last, to which he is drawn, would explain the emergence of sentient and rational beings on the basis of developmental processes directed toward their production. That is to say, there are principles of self-organization in matter that lead to living things, that are further directed by immanent laws toward the development of consciousness and reason for the sake of coming to recognize value and act in response to it, a situation that is itself a value, the good of rational life.

There are no explicit avowals in Mind and Cosmos of theophobia, as there were in The Last Word , and Nagel allows that intentional design is a possibility, though one that he forsakes in pursuit of a naturalistic, albeit a nonmaterialistic, alternative: “I confess to an ungrounded assumption of my own, in not finding it possible to regard the design alternative 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 as naturally as they see in a smiling face the expression of human feeling.” He adds in a footnote, “I am not just unreceptive but strongly averse to the idea.”

Nagel’s candor is arresting but also troubling. First, it leads to an unwarranted association of adopting the design alternative with being disposed to see the world as expressive of divine psychology. Second, it results in Nagel’s not exploring the form and character of a design explanation. Third, it allows him to avoid asking whether his preferred account is self-sufficient or instead actually forces a design conclusion. Saying “I don’t want to go there” hardly counters the suggestion that this may be where the reasoning leads.

Where Nagel’s reasoning leads may be suggested by another Thomas”Aquinas”who proceeded from observing order in nature to concluding that it was the work of a transcendent creator. This may seem an unpromising source, given that Aquinas subscribed to ideas about nature, in particular its fixity, that were reasonably challenged six centuries later by Darwin, but that appearance is misleading. Aquinas shares Aristotle’s idea that specific natures are unchanging in themselves, but his metaphysics is far from being a static one. On the contrary, it is highly dynamic, with one cause after another taking effect in the process of potentialities coming to be actualized. Moreover, he conceives of change as occurring not only in the external interaction between substances but in the internal development of them. Consider the following passage from the Summa Theologica :

Since the generation of one thing is the corruption of another, it follows of necessity that both in men and in other animals, when a more perfect form supervenes the previous form is corrupted: yet so that the supervening form contains the perfection of the previous form, and something in addition. It is in this way that through many generations and corruptions we arrive at the ultimate substantial form, both in man and in other animals.

This is not a hitherto unnoticed statement of the evolution of species, but a description of embryological development within the womb. We can apply this scheme to the process of development not intra- but inter -nature, as providing a general abstract description of the emergence of one kind of species from another. It is entirely compatible with recognizing natural selection and adaptation as factors in accounting for the survival of species. Aquinas himself might have appreciated the explanatory power of Darwin’s idea of natural selection, as Darwin would the later discovery of the underlying vehicle of heritability, the gene.

What of the emergence of life? Like the ancients, Aquinas believed in “abiogenesis,” or spontaneous generation. He writes, “An effect is assimilated to the active cause in two ways. First, according to the same species; as man is generated by man, and fire by fire. Second, by being virtually contained in the cause; as the form of the effect is virtually contained in its cause: thus animals produced by putrefaction, and plants, and minerals are like the sun and stars, by whose power they are produced.” Leaving aside his error about the nature of generation, this passage, together with the previous one, offers a way to conceive the transition from inanimate to animate being: through the operation of a cause that has the power to bring life to another.

We need, though, to add a further Thomistic principle: The power of an activity or process can never exceed the power of the cause that produced and sustains it . Processes, on this account, unfold. They do not introduce what was hitherto wholly nonexistent.

I think Nagel might agree with this, but he desires to remain with the brute fact of a cosmos guided by teleological principles toward the emergence of consciousness and the recognition of value: “Each of our lives,” he writes, “is a part of the lengthy process of the universe gradually waking up and becoming aware of itself . . . [through an] instrument of transcendence that can grasp objective reality and objective value.” Later he summarizes his position on teleology, saying that “Organizational and developmental principles of this kind are an irreducible part of the natural order, and not the result of intentional or purposive influence by anyone.” But he then adds, “I am not confident that this Aristotelian idea of teleology without intention makes sense, but I do not at the moment see why it doesn’t.”

Nagel’s rejection of a “purposive influence,” or God, is, as the second sentence indicates, not the conclusion of an argument but just the statement of his view”and one about which he feels some uncertainty. In the fifth of his five famous proofs for God’s existence, Aquinas argues from teleology to just such an agent. “We see that things that lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result.” Hence, he continues,

It is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move toward an end, unless it be directed by some being endowed with knowledge and intelligence, as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.

While philosophers and others have shown a revival of interest in design arguments, these arguments have invoked cosmological fine-tuning or appealed to irreducible bacterial complexity. The kind of argument presented by Aquinas has been neglected because people assume that it is undermined by evolutionary theory, but it is entirely compatible with the empirical evidence of speciation, of common ancestry, and of genetic inheritance. Certainly it is at odds with scientific naturalism, but the adequacy, indeed intelligibility, of the latter is what is now at issue. And so, I suggest, it is time to revisit Thomas’ fifth way.

Three considerations recommend it. First, unlike the famous design argument of William Paley and the “irreducible complexity” arguments of Michael Behe and others, Thomas’ argument does not rest on claims about the structural relationship of parts within organs but is perfectly general. Second, it recognizes functional organization and goal-directed activity across the range of nature and not only in self-directed rational animals, and hence overlaps with the positive part of Nagel’s preferred solution. But third, application of the principle that the highest effect must be present in its cause or causes implies that the developmental process that has led to rational beings must contain reason and knowledge.

A cause endowed with knowledge and intelligence by whom all natural things are directed to their end comes close to the conclusion that the cosmos is an effect of what we might call a “transcendent purposive agent.” This theistic view offers the prospect of the unification of subjective and objective that Nagel has long pursued: It sees the world emerging from and oriented toward a reality that is both its efficient and its final cause. Such a realism finds a place for differing perspectives while subsuming them within something transcendent through the idea of a shared point of active or cognitive focus, namely God.

I hope that Thomas Nagel might yet master his fear of religion and give thought to the possibility that theism could be true, a possibility given some support by his own bold reflections on the inadequacy of scientific materialism. If he does, he might then find himself arguing from the teleological order of nature to the idea that there is such a thing as “the structure of human existence which can serve as a moral reference point.” This, by Rorty’s measure, would place him on the conservative side of the realism/antirealism, natural-law/social-construction debates, and to that extent align him with the Catholic Church and its friends in other ecclesial communities and faiths. It is hard to know who would be most or least amused by this: Rorty, Nagel”or the pope.

John Haldane is professor of philosophy at the University of St. Andrews and chairman of the Royal Institute of Philosophy.