Philosopher Thomas Nagel reviewed Dawkins’ book for The New Republic. Sadly, the review does not seem to be freely available online.
Nagel begins with the standard talking points about Dawkins working outside his field of expertise and about how contemptuous he is of religion. After a few hundred words of this, he gets down to business. He describes the argument from design, and then offers two objections commonly levelled at it. Let me briefly mention the second one:
Second, the designer and the manufacturer of a watch are human beings with bodies, using physical tools to mold and put together its parts. The supernatural being whose work is inferred by the argument from design is not supposed to be a physical organism inside the world, but someone who creates or acts on the natural world while note being a part of it.
He goes on to say:
But the second difference is more troubling, since it is not clear that we can understand the idea of purposive causation – of design – by a non-physical being such as a watchmaker. Somehow the observation of the remarkable structure and function of organisms is supposed to lead us to infer as their cause a disembodied intentional agency of a kind totally unlike any that we have ever seen in operation.
This is one of the main points I made in my recent CSICOP essay on this subject. It’s nice to have a philosopher of Nagel’s caliber back me up on it!
I also agree with Nagel’s response to this point:
Still, even this difference need not be fatal to the theistic argument, since science often concludes that what we observe is to be explained by causes that are not only unobservable, but totally different from anything that has ever been observed, and very difficult to grasp intuitively. To be sure, the hypothesis of a divine creator is not yet a scientific theory with testable consequences independent of the observations on which it is based. And the purposes of such a creator remain obscure, given what we know about the world. But a defender of the argument from design could say that the evidence supports an intentional cause, and that it is hardly surprising that God, the bodiless designer, while to some extent describable theoretically and detectable by his effects, is resistant to full intuitive understanding.
I would only add that we had better be certain the evidence really does point to design before we accept this sort of special pleading.
Nagel next describes Dawkins’ approach to this argument, identifying both a positive point and a negative point. The positive point is that the design hypothesis is unnecessary, since natural causes, particularly evolution by natural selection, is an adequate explanation of complexity. The negative point is that any God capable of creating the universe would himself be so complex as to require an explanation.
In response to this second point, Nagel points out that Dawkins’ logic would only be reasonable if God were assumed to be a physical being, made out of atoms like the complex biological entities we are trying to explain. Since God is assumed to be supernatural, he is excused from needing such an explanation. Nagel sums up this line of argumentation as follows:
All explanations come to an end somewhere. The real opposition between Dawkins’ physicalist naturalism and the God hypothesis is a disagreement over whether this end point is physical, extensional, and purposeless, or mental, intentional, and purposive. On either view, the ultimate explanation is not itself explained. The God hypothesis does not explain the existence of God, and naturalistic physicalism does not explain the laws of physics.
It is true, of course, that in explaining the complexity of the universe we are ultimately forced to leave something unexplained. That said, there is a huge difference between leaving the laws of physics unexplained on the one hand, and leaving God unexplained on the other.
The laws of physics are known to exist, you see. By going Dawkins’ route we take the awesome complexity of the universe and explain it in terms of the simplest things we know to exist. Not too shabby.
In going the God route we hypothesize into existence a being far more difficult to comprehend than the universe itself. Nagel himself has already pointed to some of those difficulties. And while it’s all well and good to place God outside of nature, one wonders if anyone has ever stopped wondering where God came from by doing so.
The fact is no one can really understand what it means for God to exist outside of time. Or to say that he has no physical structure but can nonetheless direct the motions of physical entities. Or bring whole universes into being with one act of his disembodied will. These are all just euphemisms for, “We have no idea at all where the universe came from.”
We’re stuck with the laws of physics. We know they exist, and if we can’t explain them in terms of anything simpler we’ll just have to live with that. But we are not stuck with God. Invoking such an entity as an explanation for the universe is not something we should do lightly. Rather, it is something we should only do out of utter desperation.
From here Nagel introduces a third possibility:
This entire dialectic leaves out another possibility, namely that there are teleological principles in nature that are explained neither by intentional design nor by purposeless physical causation – principles that therefore provide an independent end point of explanation for the existence and form of living things.
This, alas, is where Nagel starts going off the deep end. You will search his essay in vain for any clear statement of what these teleological principles are. Indeed, if they are not the product of intelligent design, and they do not arise naturally from the laws of physics, one wonders where they come from at all.
Nagel’s next step is to turn the “Who created God?” question back on Dawkins. Evolution is all well and good, Nagel argues, but it functions only when there is some sort of mechanism of heredity in place. Natural selection might explain how we go from simple organisms to complex organisms, but since it leaves the origin of heredity unexplained it can’t be the ultimate explanation for anything.
No one disagrees, but consider what Nagel says next:
But since the existence of [DNA] or something like it is a precondition of the possibility of evolution, evolutionary theory cannot explain its existence. We are therefore faced with a problem analogous to that which Dawkins thinks faces the argument from design; we have explained the complexity of organic life in terms of something that is itself just as functionally complex as what we originally set out to explain. So the problem is just pushed back one step; how did such a thing come into existence.
This is just wrong. DNA simply isn’t as functionally complex as the organisms in which it resides. It is far easier to explain the emergence of DNA via the blind laws of physics and chemistry than it is to explain functional organisms by such laws. The origin of life remains unsolved of course, but there is no shortage of possible explanations for how physical laws led to the emergence of DNA.
In other words, explaining the origin of DNA is just a separate problem from explaining how complex organisms arise once DNA comes on the scene. Nagel spends a few paragraphs being generally dismissive of origin of life scenarios, but the fact remains that as a refutation of Dawkins this line of attack is a dud.
Nagel’s final point involves a criticism of reductionism:
The reductionist project usually tries to reclaim some of the originally excluded aspects of the world, by analyzing them in physical – that is, behavioral or neurophysiological – terms; but it denies reality to what cannot be so reduced. I believe the project is doomed – that conscious experience, thought, values, and so forth are not illusions, even though they cannot be identified with physical facts.
The problem here is not hard to spot. Nagel has no basis for his assertion that the items on his little list cannot be identified with physical facts. Indeed, one wonders what they can be identified with, if not physical facts. This is the problem I have with all anti-reductionistic rhetoric. It is not that people like Nagel are trying to open our eyes to a different form of explanation. It is that they desperately want things like consciousness to be mysterious. Scientists are trying to understand these phenomena using tools that have been overwhelmingly successful in every domain where they have been tried. Anti-reductionists prefer to leave things unexplained.
Nagel seems to acknowledge this difficulty. He writes:
Any anti-reductionist view leaves us with very serious problems about how the mutually irreducible types of truths about the world are related. At least part of the truth about us is that we are physical organisms composed of ordinary chemical elements. If thinking, feeling and valuing aren’t merely complicated physical states of the organism, what are they? What is their relation to the brain processes on which they seem to depend? More: if evolution is a purely physical causal process, how can it have brought into existence conscious beings?
Those are, indeed, very serious problems. The day anti-reductionists can provide some answers to them is the day I will start taking them seriously.