In Mind & Cosmos, renowned American philosopher Thomas Nagel calls into question the dominant scientific understanding of the human mind. Most scientists today believe that our minds can be fully explained in terms of the physical materials of which they are composed—hence the descriptor “materialistic reductionism.” Moreover, these scientists are convinced that our minds came into being through a long historical process, in which self-replicating life first emerged through a set of accidental chemical chain reactions, and then evolved through the undirected forces of natural selection working on genetic mutation, finally producing the diversity of life as we know it (including us humans with our capacities for reason and morality)—this story is called Neo-Darwinism. So, according to Nagel, the Neo-Darwinian materialists are attempting to give their own answers to two interrelated questions with which any theory of mind must grapple: the constitutive question (what is the mind actually composed of, and how is it related to the physical world?) and the historical question (how did such minds actually come to exist in the world?).
Nagel believes that the Neo-Darwinian materialists fail on both counts. Our minds—including the features of consciousness, cognition, and value—cannot be reduced to their physical components alone, and a purely physical account of evolution from non-life to life to consciousness to rationality is inadequate. The reasons for their failure, according to Nagel, are numerous: 1) it is highly unlikely that the emergence of life from non-life was an accident, 2) it is highly unlikely that undirected evolution alone can account for the diversity and complexity of life as we know it, 3) consciousness is not sufficiently explained by brute matter, and 4) Neo-Darwinism cannot account for the existence of objective reason and morality, nor for the existence of creatures capable of tapping into that objective reality.
Now these objections have been raised by creationists and proponents of intelligent design for quite some time. In that respect, Nagel isn’t really saying anything more than what folks like C.S. Lewis, Cornelius Van Til, Alvin Plantinga, and Victor Reppert have already said. What makes Nagel’s book so interesting is the fact that Nagel himself is a committed atheist, and he therefore attempts to present an alternative naturalistic (but not materialistic) account of mind’s nature and origins. According to Nagel, explanations of mind fall into three categories: causal (or physical, which is the current reigning view among scientists), intentional (or theistic, which represents the ID minority), and teleological (or goal-oriented). In the thought of most people, the intentional and teleological categories are one and the same. But Nagel opts for a “teleological naturalism” which understands the universe itself to be inherently biased toward the production of conscious, rational life (he describes the universe as gradually “waking up”). These teleological forces are by their very nature not subject to empirical, scientific discovery, and so Nagel’s view may be understood as a form of double-aspect theory or panpsychism.
In my opinion, Nagel is too dismissive of the theistic option, which seems to have greater explanatory power. Nagel favors a naturalistic explanation because it does not have to posit the existence of entities external to the universe (like God). But when one asks the question why such a universe as ours exists—one that has within it the inherent properties and inclinations to produce conscious, rational beings like ourselves—Nagel seems to be in no better of a position than the materialists who, at the end of the day, can only shrug their shoulders and say, “This is just how things are” (17). The universe’s existence is taken to be simply an inexplicable brute fact. But how is theism any different? When asked why God himself exists, do we too simply shrug our shoulders and say, “That’s just how he is?” On this point, however, we need to distinguish between contingent truths and necessary truths. Our universe is evidently contingent—that is, we can quite easily imagine it existing differently than it is, or not existing at all. But God’s existence is necessary; he could not be other than he is. A necessary truth seems to have greater explanatory value than a contingent truth, and this point counts in favor of theism over against any supposed teleological naturalism. (Side note: Nagel is also rightly skeptical of the “multiple worlds” explanation, which posits that there may be an infinite number of contingent universes, and ours happens to be one with the right conditions for rational life. That’s like trying to solve the problem of winning the cosmic lottery by suggesting that we have bought all the tickets; 95n9.)
Having looked at some of the reviews of Nagel’s book, I find it unsurprising that the majority of the scientific community have reacted with hostility to his critiques. In the New York Review of Books, biologist H. Allen Orr argues that a materialist account of the origin of life is not that implausible, given developments in the so-called “RNA world hypothesis” since the 1980’s. In response, I would direct readers to a critique of this hypothesis at Reasons to Believe. As a layman I can only express my skepticism that such a hypothesis can do the heavy lifting that materialists require of it.
Orr also seems to think that the reality of both adaptations from complex-to-simple and the extinctions of entire species count in favor of theories of undirected evolution over against teleological theories. But this presupposes that teleology may only have certain known goals in mind (such as moving from simple to complex, or toward the survival of all forms of life). But what if a different goal was intended in some instances—for example, what if the goal of the extinction of the dinosaurs was to provide us modern humans with an ample supply of petroleum? This is purely hypothetical of course, but the point is that we don’t have to know the directed goal for everything to recognize the directed goal for some things.
Orr’s objections to Nagel’s philosophical argument from consciousness are equally unpersuasive. Orr admits the mystery of how one can get from chemical processes in the brain to actual subjective experiences, but he then seems to appeal to a “materialism of the gaps” (a phrase Nagel himself uses, 127): science may someday be able to arrive at an explanation for the subjective experience of consciousness, even if such an explanation runs counter to our own intuitions. But here the problem does not seem to be merely a lack of empirical evidence, which may be remedied by future research. There is an in principle barrier between the tools that science has at its disposal and the nature of our conscious minds. Science is great at studying empirical, objective phenomena, but there is no way to turn it “inwards” on our own subjective state. That’s where science ends and philosophy (or theology) begins.
Orr’s second reason for dismissing Nagel’s argument from consciousness is also rather weak. He supposes that the reason why we can’t seem to solve the mind-body problem is because of our cognitive limitations as evolved creatures. This may be a coherent reason given Orr’s own premises, but it is essentially circular and therefore will not persuade anyone who questions the evolutionary premise to begin with. Further, as Nagel himself states at the end of his book, we have no reason to believe that such cognitive limitations exist, and we should therefore keep trying so solve the problem (128).
In all, Mind & Cosmos is a worthwhile read, and it is sure to have an impact in years to come. But in the final analysis, I will have to say of Nagel what he says of intelligent design proponents: while the criticisms he raises are valid and need to be taken more seriously, his own proposed solution is much less persuasive.