Nagel’s “Mind and Cosmos”

So, I recently read Nagel’s “Mind and Cosmos”, and figured I should probably comment on it. The first thing that I want to say about it is that it’s far too short for the ambitions that he at least claims to have. For the most part, I really didn’t get how he was attacking the materialist neo-Darwinian conception of nature, since he wasn’t explicit in most cases and sometimes didn’t even seem to make the link. Either the book should have just raised the issues as puzzles or should have gone into some detail about what is meant by a materialist neo-Darwinian conception of nature. Neither seems to have been done, or at least done sufficiently, and the book suffers as a result. However, I think I’ve managed to put the pieces together, and so am going to outline that here. Note that this is my take on what was said, and so is open to challenge.

First, what do people mean by the neo-Darwinian idea? There have been a number of people who are taking on a neo-Darwinian conception or theory, and the responses from the usual people seem to miss the concerns of those who are taking on Darwin. Fodor and P-P go after Darwin, as does David Dobbs, with the obligatory reply from Jerry Coyne. But it seems that those who criticize people like Fodor, Dobbs and Nagel are somewhat confused about what the actual argument is, especially since none of these people deny that natural selection occurs in nature, and often even accept that it is a very important mechanism in evolution. So what’s the complaint, then?

To me, it seems that the detractors of Darwinianism oppose it not as a descriptive theory of how the world works (in that it is a mechanism in the world that produces traits) but as an explanatory theory, where you can appeal to the Darwinian view as an explanation for the traits that we have. The simple Darwinian story that there was a mutation that was then selected for because it had a clear benefit is a nice description of a basic mechanism, but when you toss in free riders, multiple traits with benefits, and the fact that genetic predisposition does play a large roll — mutations can only produce traits that the genes will actually produce when encoded — if you are trying to look at any specific trait it is actually quite unlikely that that trait was produced by that simple mechanism, or at least directly produced by it. And if that’s the case, then if you pick out a trait and start trying to explain why we have that trait and not an opposing trait by saying “Well, let’s see what benefit it might have had … oh, well, there’s a benefit that it has, and so that must be what was selected for, and so there’s your explanation” you are likely to come up with the wrong answer.

Nagel relies on another problem with this sort of explanation, which is the “just-so” story, meaning that you end up saying that the trait either developed just because we had the right sort of mutation, or because it had some unidentified benefit (or vaguely defined one), then all you’ve said is that, essentially, it just happened. If, at any point, you have to say that something just happened, you haven’t really explained it; to Nagel, getting into this state is essentially saying “Evolution did it” which is the equivalent of “God did it” in terms of explanations, except that since God is at least seen as being an intentional being we can at least try to explain it in terms of what God wants to see happen. Which, of course, is not available for evolution.

My view, then, is that Nagel is trying to throw out three important traits or mechanisms in at least some biological beings — mostly humans — that he thinks the simple Darwinian view has to try to explain with “It just happened”. If that’s the case, then the simple Darwinian view cannot provide an explanation for those traits or mechanisms, and so there are important biological mechanisms that cannot be explained by Darwinism, and so claims that we can use the neo-Darwinian conception of nature to explain everything are false, and that we can’t even explain everything biological using it. This is what he means when he says that if he’s right this would revolutionize biology. So how does he go about showing that?

He starts with one of his biggest personal problems: consciousness. Or, more precisely, conscious/phenomenal experience; what it is to be like something. In order for consciousness to have evolved under the neo-Darwinian view, it has to provide us with an actual external benefit for natural selection to work on. However, phenomenal experience is purely subjective; no one can externally observe our internal reactions. You can’t feel my pain. So if consciousness is going to have a selectable benefit, it’s not going to be direct, but instead indirect because of its impact on our behaviour. But under the materialist view of mind, it is the physical neurons and their connections that actually produce our external behaviour; the subjective experience is at best a product of what the brain is doing. So, then, under the materialist view, subjective experience is just a side effect of what neurons are really doing, which is producing external behaviour. Therefore, the details of our subjective experiences don’t have a causal impact on our behaviour, but at best reflect different things our neurons are doing. Fine.

But then the question is: why do we have subjective phenomenal experience, and why does it have the characteristics it has? Why is pain painful? Why does the colour blue look the way it does? Because the materialist theory says that it’s just what the neurons do, and that the details of that experience aren’t selected, all it can say is “Because that’s what the neurons do”. But that’s not an explanation. So we’re going to have to go outside of natural selection to explain having subjective experiences at all, let alone the details of why we experience what we do. Since subjective experience is an important part of some biological organisms — at least the “higher” animals — that’s an important mechanism that neo-Darwinianism simply cannot explain.

Nagel moves on to cognition. I had an impossible time figuring out what he meant here until I recalled that he referenced Plantinga, and so have come to the conclusion that he is using a modified version of Plantinga to attack cognition. The main idea is this: we want to know that our cognitive faculties are reliable. The neo-Darwinian argument would be that we know that our cognitive faculties are reliable because we know they evolved, and evolution selects for utility, and cognitive faculties that produce truths about the world will be useful and more useful than once that produce falsehoods. Thus, if the theory of evolution is true, our cognitive faculties are reliable, and since we know the theory of evolution is true, we know our cognitive faculties are reliable. But since knowledge requires us to have justified true beliefs, what is it that justifies our belief that the theory of evolution is true? Well, we’d claim that it is scientifically proven using reason and evidence, of course. But those are our own cognitive faculties, and we started out being uncertain about them. If we want to justify our belief that our cognitive faculties are reliable by appealing to the theory of evolution, it had better not be the case that we justify the theory of evolution by appealing to those same cognitive faculties that we were hoping the theory of evolution would prove reliable. Thus, that answer is circular, and not acceptable.

So, one way out would be to say that our cognitive faculties just are reliable, or that we have to rely on them because that’s all we have. Both of these would be giving up on the question. The other way out would be to demonstrate that our cognitive faculties are the sort of cognitive faculties that would inherently produce true beliefs, and so then say that we developed cognitive faculties that did produce true beliefs — because these sorts of faculties are the sort that do that — and then once that occurred natural selection could solidify them in us by their benefits. In short, we got lucky and picked up the right sort of faculties to produce truths, and we know that these are the right sorts of faculties because we can prove that they are without appealing to natural selection. Putting aside some potential difficulties with making this sort of judgement with unproven cognitive faculties, either way out forces us to abandon the neo-Darwinian view as the explanation for the reliability of our cognitive faculties, and particularly as what justifies our belief that they are reliable, thus again making an important biological mechanism that cannot be explained by the Darwinian view.

Nagel ends with value. This one is far more straightforward. Value requires us to judge something as good or bad, or right or wrong. And we seem to think that these judgements are true in some interesting way. And they do seem to have an impact on our behaviour. However, the only external impact they have is to get us to move towards or away from something. So, from the external perspective, good and bad are identical to attractive and aversive. And if that’s all that natural selection can select on, then what is the use of having good or bad at all? Why not simply have attractive and aversive? If they always work out the same way — ie our calculations of value always correspond with our calculations of attractiveness and aversion — then the two really are the same thing, and if they are ever different then how did we ever select for value, or for some kind of value that isn’t just subjectively true (meaning, attractive to me)? If value isn’t just going to be subjective, then we have to be mapping it to something objective, but if evolution only selects for attractive and aversive, where is it that we can find this value or justify having this value hook up to the right things? Again, evolution comes back with “It’s just right”, which isn’t an explanation, and so we again have something important about biological organisms — pretty much only humans in this case — that can’t be explained by natural selection, and thus not by neo-Darwianian reductive views.

I’ll repeat my caution that these are my interpretations of what Nagel has said, not precisely what Nagel has said himself. I think I’m interpreting him correctly, but I could be wrong. But, to me, this is what he’s on about, and while they may not be credible they do seem, at least to me, to deserve some consideration.

One Response to “Nagel’s “Mind and Cosmos””

  1. What I Did on My Winter Vacation … | The Verbose Stoic Says:

    […] I finally read some of the outstanding books on my list, reading and commenting on Nagel’s “Mind and Cosmos” and starting reading Parfit’s “On What Matters”, which will take a while. I hope […]

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