I am beginning to feel a little sorry for Thomas Nagel. It looks as if the only favorable mainstream reviews he will receive for his efforts in Mind and Cosmos will be from theists. What excites the theists' approbation, of course, are not Nagel's positive panpsychist and natural-teleological suggestions, which remain within the ambit of naturalism, but his assault on materialist naturalism. As Alvin Plantinga writes in his excellent review, Why Darwinist Materialism is Wrong, "I applaud his formidable attack on materialist naturalism; I am dubious about panpsychism and natural teleology." And so Nagel's predicament, at least among reviewers in the philosophical mainstream, seems to be as follows. The naturalists will reject his book utterly, both in its negative and positive parts, while the theists will embrace the critique of materialist naturalism while rejecting his panpsychism and natural-teleologism.
Plantinga's review, like ancient Gaul, est in partes tres divisa.
In the first part, Plantinga take himself to be in agreement with Nagel on four points. (1) It is extremely improbable that life could have arisen from inanimate matter by the workings of the laws of physics and chemistry alone. (2) But supposing life has arisen, then natural selection can go to work on random genetic mutations. Still, it is incredible that that all the fantastic variety of life, including human beings, should have arisen in this way. (3) Materialist naturalism cannot explain consciousness. (4) Materialist naturalism cannot explain belief, cognition, and reason.
In the second part of his review, Plantinga discusses Nagel's rejection of theism. Apart from Nagel's honestly admitted temperamental disinclination to believe in God, Plantinga rightly sees Nagel's main substantive objection to theism to reside in theism's putative offense against the unity of the world. But at this point I hand off to myself. In my post Nagel's Reason for Rejecting Theism I give a somewhat more detailed account than does Plantinga of Nagel's rejection.
In the third part of his review, Plantina expresses his doubts about panpsychism and natural teleology. I tend to agree that there could not be purposes without a purposer:
As for natural teleology: does it really make sense to suppose that the world in itself, without the presence of God, should be doing something we could sensibly call “aiming at” some states of affairs rather than others—that it has as a goal the actuality of some states of affairs as opposed to others? Here the problem isn’t just that this seems fantastic; it does not even make clear sense. A teleological explanation of a state of affairs will refer to some being that aims at this state of affairs and acts in such a way as to bring it about. But a world without God does not aim at states of affairs or anything else. How, then, can we think of this alleged natural teleology?
Plantinga ends by suggesting that if it weren't for Nagel's antipathy to religion, his philosophical good sense would lead him to theism.
I think I shall have to write a number of posts on this exciting and idea-rich book by one of our best philosophers. Here is the first.
Short (128 pp.) and programmatic, Thomas Nagel's new book explores the prospects of an approach in the philosophy of mind that is naturalistic yet not materialistic. His approach is naturalistic in that he locates the source of the world's intelligibility in it, and not in a transcendent being such as God outside it. As Nagel rightly observes, "Theism pushes the quest for intelligibility outside the world." (p. 45)
Nagel's approach is also naturalistic in that he views mind as a biological phenomenon as it could not be if substance dualism were true. But while naturalistic, Nagel also rejects "psychophysical reductionism" or "reductive materialism." Thus he rejects naturalism as currently articulated without embracing any form of anti-naturalism such as theism. Nagel, we might say, seeks a middle path between theistic anti-naturalism and materialistic naturalism. The latter is just materialism which Nagel defines as follows:
Materialism is the view that only the physical world is irreducibly real, and that a place must be found in it for mind, if there is such a thing. This would continue the onward march of physical science, through molecular biology, to full closure by swallowing up the mind in the objective physical reality from which it was initially excluded. (37)
This is a useful definition. Materialism is either eliminativist or reductivist. Now obviously there is such a thing as mind, so eliminativism is not an option. (41) My arguments against it here. So the materialist must try to show that mind belongs to objective physical reality and that everything about it is understandable in the way everything else in objective physical reality is understandable. In this way materialism closes upon itself, explaining not only the world the mind engages, but the engaging mind itself. I agree with Nagel that reductive materialism is untenable.
Treading his via media between theism and materialism, Nagel reopens the case for neutral monism and panpsychism. How does he get to these positions? This is what I will try to figure out in this post.
Mind is a biological phenomenon. We are organisms in nature, not Cartesian egos contingently attached to physical bodies. But we are conscious organisms. We are subjects of such qualitative states as pleasure and pain, and we are individuals with a subjective point of view. If psychophysical reductionism fails, as both Nagel and I maintain, then physical science, even if it can explain our existence as organisms adapted to an environment, cannot explain our existence as conscious organisms. We are not just objects in the world, we are subjects for whom there is a world. Even if the first fact can be adequately explained by physical science, the second, our subjectivity, cannot be.
Given the failure of psychophysical reductionism, and given that mind is a biological phenomenon encountered only in conscious organisms that have evolved from pre-conscious organisms, evolutionary theory cannot be a purely physical theory. (44) The 'makings' of conscious organsims must already be present in pre-conscious life forms. In this way the mind-body problem spreads to the entire cosmos and its history. Thus "the mind-body problem is not just a local problem" that concerns such minded organisms as ourselves. (3)
Inanimate matter evolved into pre-conscious life forms, and these evolved into conscious life forms. Since conscious organisms qua conscious cannot be understood materalistically, the same is true of pre-conscious life forms: the reduction of biology to physics and chemistry will also fail. This is because life must contain within it the 'makings' of consciousness. That is my way of putting it, not Nagel's.
Turning it around the other way, if we are to have an adequate naturalistic explanation of conscious organisms, then this cannot be "a purely physical explanation." (44) And so Nagel floats the suggestion of a global (as opposed to local) neutral monism "according to which the constituents of the universe have properties that explain not only its [mental life's] physical but its mental character." (56) Conscious organisms are composed of the same ultimate stuff as everything else is. For this reason, neutral monism cannot be kept local but goes global or "universal." (57) The idea, I take it, is that even the merely physical is proto-mental, the merely living being even more so. When conscious organisms arrive on the scene, the proto-mental constituents achieve an arrangement and composition that amounts to mental life as we know it.
Now how do we get from this universal neutral monism to panpsychism? Well, a universal neutral monism just is panpsychism: the ultimate constituents of nature are all of them proto-mental. Mind is everywhere since everything is composed of the same proto-mental constituents. But it is equally true that matter is everywhere since there is nothing mental or proto-mental that is not also physical.
Thus we arrive at a position that is neither theistic nor reductively materialistic.
Let me now try to list the key premises/assumptions in Nagel's argument for his panpsychistic naturalism.
1. Consciousness is real. Eliminativist materialism is a complete non-starter.
2. Naturalism: Consciousness occurs only in conscious organisms, hence cannot occur without physical realization. Mind is a biological phenomenon. No God, no Cartesian minds. No substance dualism, no theism.
3. Reductive Materialism (psychophysical reductionism) is untenable.
4. Consciousness cannot be a brute fact. Mind is not an accident but "a basic aspect of nature." (16) It cannot be that consciousness just inexplicably occurred at a certain point in evolutionary history when organisms of a certain physical complexity appeared. The arrival of conscious organisms needs an explanation, and this explanation cannot be an explanation merely of their physical character. It must also explain their mental character. But this materialism cannot do. Hence "materialism is incomplete even as a theory of the physical world, since the physical world includes conscious organisms as its most striking occupants." (45)
5. Nature is intelligible. Its intelligibility is inherent in it and thus not imposed on it by us or by God. The intelligibility of nature is not a brute fact: nature doesn't just happen, inexplicably, to possess a rational order that is understandable by us. I take Nagel's position to be that intelligibility is a necessary feature of anything that could count as a cosmos. Thus it needs no explanation and surely cannot have a materialist one: it cannot possibly be the case that the intelligibility of nature arose at some time in the past via the operation of material causes. The universe is so constituted as to be understandable, and we, as parts of it, are so constituted as to be able to understand it. (16-17)
I accept all of these propositions except (2). So in a subsequent post I must examine whether Nagel's case against theism is stronger than his case for his panpsychism.