Thomas Nagel on the Naturalism of Daniel Dennett

Thomas Nagel, without question one of my favourite philosophers and writers, has a nifty review of Daniel Dennet’s latest work in The New York Review of Books.

Nagel has written quite a few articles lately in the London and New York Reviews, which is splendid for too much Nagel is never enough.

The subject of Nagel’s bat like instincts in this case is Dennett’s From Bacteria to Bach and Back: The Evolution of Minds

What makes Nagel’s review especially noteworthy is that Dennett’s thesis, as Nagel presents it, is so at odds with that of his own Mind and Cosmos. I have not read the Dennett book as of yet, so what I say here is heavily qualified.

Nagel was born in Belgrade and Dennett, when visiting Belgrade, marvelled at the humanist manner with which the US does its killing. Dennett saw what he wanted to see, and Nagel, effectively, argues that Dennett sees in nature what he wants to see namely the ubiquitous handiwork of evolution by natural selection.

Nagel’s entrance is a memorable one

For fifty years the philosopher Daniel Dennett has been engaged in a grand project of disenchantment of the human world, using science to free us from what he deems illusions—illusions that are difficult to dislodge because they are so natural

This is indeed correct. Dennett is a rare species of philosopher, one very much conversant with the sciences and one whose own philosophy is framed by science. This is an especial strength, but it can also be a weakness especially when broad all encompassing conclusions are reached upon the basis of a partial and premature science.

Nagel certainly is suggesting so.

I should say that I am wholly on board with Dennett’s naturalism, but I think that Nagel, assuming his rendering of the Dennett book be accurate, has the better of the argument.

Let me, briefly, explain.

Nagel identifies the central thesis of Dennett like so

The way Dennett avoids this apparent contradiction takes us to the heart of his position, which is to deny the authority of the first-person perspective with regard to consciousness and the mind generally

Nagel associates this eliminativism with behaviourism

If I understand him, this requires us to interpret ourselves behavioristically: when it seems to me that I have a subjective conscious experience, that experience is just a belief, manifested in what I am inclined to say. According to Dennett, the red stripes that appear in my visual field when I look at the flag are just the “intentional object” of such a belief, as Santa Claus is the intentional object of a child’s belief in Santa Claus. Neither of them is real. Recall that even trees and bacteria have a manifest image, which is to be understood through their outward behavior. The same, it turns out, is true of us: the manifest image is not an image after all

The source of Dennett’s behaviourism, as with the original, is physicalism

According to Dennett, however, the reality is that the representations that underlie human behavior are found in neural structures of which we know very little

Moreover

And he asks us to do this because the reality of such phenomena is incompatible with the scientific materialism that in his view sets the outer bounds of reality

There wouldn’t be much disagreement here between Colin McGinn and Dennett. Consider McGinn’s dismissal of neuromania or neurophilosophy in the same publication

Of course, my point was never that the progress of neuroscience can be dismissed as “neuromania.” It was that insisting that neuroscience is the key to philosophical problems is a form of neuromania. I like neurons well enough—I just think they are not the way to understand beauty, goodness, and truth. Hardly a radical position, I would have thought

Neuromania or neurophilosophy is the thesis that neuroscience can provide answers to many of the traditional philosophical problems, especially those associated with the first person perspective at issue here, a position McGinn rightly rejects, as does Dennett.

For Dennett, going by Nagel’s rendering, the problems are not answered so much as eliminated.

The impulse here is to reject what cannot fit into our physical world view, and because subjective experience, the mental as it were, cannot fit into our physical world view we reach for the guillotine and eliminate when and where necessary with rational fury.

I agree with Nagel that this is not correct, for much the same reasons

The spectacular progress of the physical sciences since the seventeenth century was made possible by the exclusion of the mental from their purview. To say that there is more to reality than physics can account for is not a piece of mysticism: it is an acknowledgment that we are nowhere near a theory of everything, and that science will have to expand to accommodate facts of a kind fundamentally different from those that physics is designed to explain

That said, the conclusions reached by Nagel in Mind and Cosmos are not ones I would concur with.

My position would be that the mental is outside of physics as we know it, but that its incorporation into a physicalist world view could be made possible should our understanding of the physical world deepen.

Ultimately, I would subscribe to something akin to the naturalistic panpsychism of Galen Strawson.

There is a, rudimentary, sense in which one mental concept enters the physics we know. I speak of the concept knowledge, and its rather mysterious role in statistical mechanics and quantum mechanics. We have here a mechanics which is difficult to grasp without the concept knowledge. This to me seems to be a signpost pointing toward a, doubtless distant, unification of the physical with the mental.

The follies of eliminativism, contra Nagel, does not mean that explanation must go beyond the physical. It means that our understanding of the physical needs to deepen and broaden.

On the matter of evolution there is no doubt that Dennett is among the congregation of what Stephen Jay Gould referred to as Darwinian fundamentalists, and that as one of its most pious friars.

However, the history of life from bacteria to Bach exhibit a number of what the biologist Christian de Duve referred to as “singularities,” the emergence of which is hard to explain through phyletic gradualism.

According to Nagel Dennett is well aware of this

Dennett identifies two unsolved problems along this path: the origin of life at its beginning and the origin of human culture much more recently. But that is no reason not to speculate

Again, I would not go as far as Nagel does in Mind and Cosmos regarding evolution. I would suppose that our understanding of evolution needs to, and indeed can, deepen beyond the neo Darwinian synthesis not that the evolutionary picture is “almost certainly false.”

I am thinking that evolution could be explained entirely in terms of physics, and, quite to the point, our understanding of evolution has progressed since Darwin’s time precisely by incorporating physicalist explanation. I see no reason why this process cannot continue so that evolution becomes a theory of physics. There is still much to learn about the development of form, for instance.

I suspect that ecology will become more important as our understanding of evolution progresses.

The concluding points of Nagel regarding what I take to be strong artificial intelligence I find puzzling.

Nagel cites Dennett thus

The real danger, I think, is not that machines more intelligent than we are will usurp our role as captains of our destinies, but that we will over-estimate the comprehension of our latest thinking tools, prematurely ceding authority to them far beyond their competence

Which is to suppose that we will cede authority to machines of our own creation, but let us not do so prematurely. Assuming strong AI to be correct, which I don’t by the way, it seems either they will be our slaves or we theirs.

Perhaps we will come to cooperate, but Hawking’s argument against SETI is apposite here. It would be better that we don’t build such machines as odds are they will enslave us.

That shouldn’t bother Dennett too much for the finer human qualities that render the concept slavery abhorrent are but illusions.