Reference Material:
A Materialist Theory of the Mind by David Armstrong
The Conscious Mind by David Chalmers
Here we continue our look at the manifestations of naturalism in the philosophy of mind. Last time out, we considered David Chalmers’ views which, while broadly naturalist in character, are at least somewhat anti-physicalist. We’ll now compare Chalmers’ positions with those of David Armstrong, who can probably be placed more squarely in the physicalist/materialist camp. Let’s dive in.
I’ll start by overviewing Armstrong’s general views vis-à-vis naturalism as they appear in A Materialist Theory of the Mind. He gives an interesting argument relatively early in the book which I broadly sympathize with. It goes something like this. As science has progressed, many have come to believe that chemical phenomena are reducible to (supervene on) physical phenomena, biological phenomena reducible to chemical phenomena, etc. Examples that easily come to mind would be the quantum mechanical description of the hydrogen molecule, reducing the chemistry of the molecule to the physics of the atom, or the chemical/molecular description of the DNA molecule, reducing the biological function of the DNA molecule to its chemical structure and properties. This supervenience would imply that, in principle, chemical phenomena could be predicted with physics alone (plus sufficiently powerful computational capacity) and biological phenomena from chemistry alone. In some sense, at rock bottom, everything is physical stuff operating according to the laws of physics. Now
The conclusion – “if all the sciences except psychology are, in theory, very complex particular cases of the fundamental science of physics, it seems unlikely that psychology is an exception” (50). Armstrong himself admits that this argument is not logically water-tight – psychology could be an exception – but it has its rhetorical force. It certainly resonates with me. Reductive physical science has had such great success in so many areas. It would be a surprise at this point if we ran into roadblocks that, instead of being rooted in technological limitations, resource scarcity, or failure of imagination, were instead grounded in deep philosophical, seemingly insurmountable, issues.
As a brief aside, Armstrong’s views here relate to an earlier blog topic – emergence. If everything in the world can, in principle, be described by the laws of physics, there can be no strong emergence (in Mark Bedau’s framework). Armstrong makes this clear at other points in the book as well, when he admits the possibility of predicting human behavior in principle (162) and when he sees no reason to posit emergent laws in the nervous system to account for mind or behavior (359). With this perspective, Armstrong is right in line with positions taken in this blog.
Armstrong brings this naturalist/physicalist worldview to his philosophy of mind, which I have a lot of sympathy for. He advocates for what he calls the central-state theory of the mind, that mental states are to be identified with physical states of the brain and/or central nervous system (10). He makes some general statements elsewhere that buttress this physicalist take on the mind. In particular, he claims that causality for mental events is the same as causality for physical events (83). So far, Armstrong is preaching to the choir.
It’s worth pausing here for a moment to reflect on what Chalmers would think about these views as laid out so far. As far as I understand, he would be in broad agreement. He would agree that the world unfolds according to the laws of physics alone, and that therefore strong emergence doesn’t exist. He would agree that every mental state can be identified with (he might want to say associated with) a physical state of the brain. And he would also agree with Armstrong about one aspect of this identification – that it is a contingent fact, not a logically necessary one (76-7, 91).
Where the philosophers would part ways would be in how to explain in more detail the nature of the identification of mental states with brain states. Armstrong defines a mental state as “a state of the person apt for bringing about a certain sort of behavior” (82). The idea is that this aptness is reflected in, and perhaps synonymous with, a certain physical brain state, and he then spends the back half of the book exploring how everyday mental states (actually all mental states, he claims) can be characterized as aptness for bringing about certain sorts of behavior.
I think Chalmers would immediately object here. To define a mental state as Armstrong has done is to define it from a purely 3rd-person, objective perspective. This type of definition completely ignores the essentially 1st-person, subjective nature of human mental life. This 1st-person subjectivity is precisely what is so hard to account for within a modern, scientific framework. Indeed, accounting for 1st-personness really just is the hard problem of consciousness. Armstrong ducks the problem from the outset with his definition of a mental state. And he continues to do so in his brief discussion of consciousness, when he defines consciousness as a specific kind of mental state, an awareness of other mental states (94-5). But this definition doesn’t explain why it is like something to have such awareness. I think for Chalmers, this account of consciousness just misses the point.
For as much criticism as Chalmers received in the previous post, it’s time he got his due. He’s right to point out (he discusses this at length in The Conscious Mind) that many philosophers “explain” consciousness, the what-it’s-like-to-be-ness of mental experience, in a way that seems to ignore the essence of the concept, the 1st-person subjectivity. After reading Armstrong, I’d have to place him in this camp – he really doesn’t deal with the core of the issue. That said, there are obviously problems with how Chalmers deals with the issue – no need to elaborate on that further at this point.
So where does that leave us? It leaves me back at Chalmers’ don’t-have-a-clue materialism. I really don’t have a good answer, but the reductive physical science paradigm is so successful at explaining such a wide range of phenomena – indeed, all phenomena except consciousness, I’d argue – that casting consciousness outside of that paradigm seems risky, but describing it within that paradigm needs to make a whole lot more sense than Chalmers’ account. However, in our efforts to explain consciousness, we needn’t reduce it to something less than we know it to be, as Armstrong seems to do. There is a name for this position – it’s called Mysterianism. We may delve into this school of thought later in the blog. For now, we’ll leave the philosophy of mind to rest.
A Materialist Theory of the Mind by David Armstrong
The Conscious Mind by David Chalmers
Here we continue our look at the manifestations of naturalism in the philosophy of mind. Last time out, we considered David Chalmers’ views which, while broadly naturalist in character, are at least somewhat anti-physicalist. We’ll now compare Chalmers’ positions with those of David Armstrong, who can probably be placed more squarely in the physicalist/materialist camp. Let’s dive in.
I’ll start by overviewing Armstrong’s general views vis-à-vis naturalism as they appear in A Materialist Theory of the Mind. He gives an interesting argument relatively early in the book which I broadly sympathize with. It goes something like this. As science has progressed, many have come to believe that chemical phenomena are reducible to (supervene on) physical phenomena, biological phenomena reducible to chemical phenomena, etc. Examples that easily come to mind would be the quantum mechanical description of the hydrogen molecule, reducing the chemistry of the molecule to the physics of the atom, or the chemical/molecular description of the DNA molecule, reducing the biological function of the DNA molecule to its chemical structure and properties. This supervenience would imply that, in principle, chemical phenomena could be predicted with physics alone (plus sufficiently powerful computational capacity) and biological phenomena from chemistry alone. In some sense, at rock bottom, everything is physical stuff operating according to the laws of physics. Now
consider what this means for a non-Materialist theory of the mind. It means that the whole world studied by science contains nothing but physical things operating according to the laws of physics with the exception of the mind. Only psychology is forced to recognize a new thing, or at any rate a new sort of property of things, in the world. (49)
The conclusion – “if all the sciences except psychology are, in theory, very complex particular cases of the fundamental science of physics, it seems unlikely that psychology is an exception” (50). Armstrong himself admits that this argument is not logically water-tight – psychology could be an exception – but it has its rhetorical force. It certainly resonates with me. Reductive physical science has had such great success in so many areas. It would be a surprise at this point if we ran into roadblocks that, instead of being rooted in technological limitations, resource scarcity, or failure of imagination, were instead grounded in deep philosophical, seemingly insurmountable, issues.
As a brief aside, Armstrong’s views here relate to an earlier blog topic – emergence. If everything in the world can, in principle, be described by the laws of physics, there can be no strong emergence (in Mark Bedau’s framework). Armstrong makes this clear at other points in the book as well, when he admits the possibility of predicting human behavior in principle (162) and when he sees no reason to posit emergent laws in the nervous system to account for mind or behavior (359). With this perspective, Armstrong is right in line with positions taken in this blog.
Armstrong brings this naturalist/physicalist worldview to his philosophy of mind, which I have a lot of sympathy for. He advocates for what he calls the central-state theory of the mind, that mental states are to be identified with physical states of the brain and/or central nervous system (10). He makes some general statements elsewhere that buttress this physicalist take on the mind. In particular, he claims that causality for mental events is the same as causality for physical events (83). So far, Armstrong is preaching to the choir.
It’s worth pausing here for a moment to reflect on what Chalmers would think about these views as laid out so far. As far as I understand, he would be in broad agreement. He would agree that the world unfolds according to the laws of physics alone, and that therefore strong emergence doesn’t exist. He would agree that every mental state can be identified with (he might want to say associated with) a physical state of the brain. And he would also agree with Armstrong about one aspect of this identification – that it is a contingent fact, not a logically necessary one (76-7, 91).
Where the philosophers would part ways would be in how to explain in more detail the nature of the identification of mental states with brain states. Armstrong defines a mental state as “a state of the person apt for bringing about a certain sort of behavior” (82). The idea is that this aptness is reflected in, and perhaps synonymous with, a certain physical brain state, and he then spends the back half of the book exploring how everyday mental states (actually all mental states, he claims) can be characterized as aptness for bringing about certain sorts of behavior.
I think Chalmers would immediately object here. To define a mental state as Armstrong has done is to define it from a purely 3rd-person, objective perspective. This type of definition completely ignores the essentially 1st-person, subjective nature of human mental life. This 1st-person subjectivity is precisely what is so hard to account for within a modern, scientific framework. Indeed, accounting for 1st-personness really just is the hard problem of consciousness. Armstrong ducks the problem from the outset with his definition of a mental state. And he continues to do so in his brief discussion of consciousness, when he defines consciousness as a specific kind of mental state, an awareness of other mental states (94-5). But this definition doesn’t explain why it is like something to have such awareness. I think for Chalmers, this account of consciousness just misses the point.
For as much criticism as Chalmers received in the previous post, it’s time he got his due. He’s right to point out (he discusses this at length in The Conscious Mind) that many philosophers “explain” consciousness, the what-it’s-like-to-be-ness of mental experience, in a way that seems to ignore the essence of the concept, the 1st-person subjectivity. After reading Armstrong, I’d have to place him in this camp – he really doesn’t deal with the core of the issue. That said, there are obviously problems with how Chalmers deals with the issue – no need to elaborate on that further at this point.
So where does that leave us? It leaves me back at Chalmers’ don’t-have-a-clue materialism. I really don’t have a good answer, but the reductive physical science paradigm is so successful at explaining such a wide range of phenomena – indeed, all phenomena except consciousness, I’d argue – that casting consciousness outside of that paradigm seems risky, but describing it within that paradigm needs to make a whole lot more sense than Chalmers’ account. However, in our efforts to explain consciousness, we needn’t reduce it to something less than we know it to be, as Armstrong seems to do. There is a name for this position – it’s called Mysterianism. We may delve into this school of thought later in the blog. For now, we’ll leave the philosophy of mind to rest.
