Neurophilosophy

Neurophilosophy and the philosophy of neuroscience (II) – Buyer Brain

Sean Carrol spoke to philosopher Patricia Churchland last year on his Mindscape podcast, where the two of them discussed the relevance of Churchland’s work in neuroscience to morality. Churchland argues that if we want to understand morality (and, I think, pretty much everything relating to mind), we need to understand the brain. This approach has resulted in her being shunned by her philosophy contemporaries, even as she has been welcomed by her neuroscience ones. In this article, I will investigate neurophilosophy, a term Churchland herself coined, as she discusses it in this podcast (to be fair, I haven’t read any of her books on the subject, so my comments in this article are restricted to the podcast), and discuss whether Churchland has been wrongly (or justly) excluded from her philosophical peers.

Definition

Neurophilosophy essentially describes an interdisciplinary approach towards topics that have formerly been firmly ensconced within philosophy departments. As I understand it, it holds that an understanding of what is happening in the brain (neuroscience) can meaningfully contribute to a discussion of the mind (philosophy). Now, it is fine to require that philosophical accounts of perception, movement, desire, etc., be informed by relevant scientific experiments and discoveries; however, I see neurophilosophy as making a much stronger claim than this. It says that the firing of neurons, the transfer of neurotransmitters, the production of hormones in the brain, etc., have some meaningful (even causal) impact on things like morality and freewill. I hold the former to be (relatively) uncontroversial, but the latter to be much less certain. Let me make the case, and you can see if you agree.

 

The Brain

To Churchland’s credit, she acknowledges that the brain is nothing like a computer. This is a fairly low bar for praise, I know, but so many intelligent people these days just cannot seem to resist the ‘brain is hardware / mind is software’ analogy, which, as I’ve complained about ad nauseum on this website, obscures far more than it illuminates. She also affirms that the body (particularly in terms of neurochemistry) is an essential, and often overlooked, aspect of mind. Another low bar, but again, refreshing to hear one of our intellectual luminaries asserting this instead of the oft-heard claim of AI enthusiasts that the mind is “substrate independent,” and all we need to generate full-blown, general AI are enough microprocessors, or qubits, arranged in just the right way.

The one sticking point I have with Churchland here (at least as far as her discussion with Carroll goes) is her claim that the brain is a causal machine. I totally agree with her that there is no mysterious ‘immaterial substance’ or ‘soul’ lurking within us (perhaps hiding out in the pineal gland), which is to say, I agree that there is nothing more than matter. However, if there is one thing modern physicists can agree on, it’s that the universe is not just weirder than we imagine, it’s weirder than we can imagine. And this extends to matter. In fact, if we’re being honest, scientists have absolutely no idea what matter is (I talk more about this here). The latest hypothesis I am aware of (as a non-expert, but interested, layperson) is that matter (i.e. fundamental particles) is considered to be the excitation of fields. In other words, matter isn’t even material! What this means is that we are overdue for a fundamental revision of what comprises the universe.

The problem is that while we know particles aren’t little lumps of ‘stuff’ interacting with other lumps of ‘stuff,’ we still think about human life (and the universe in general) as if they were. This curious disconnect leads to some profoundly inaccurate thinking, most evident perhaps in the way we discount our own conscious experience, and insist, against all reasonable, first-person evidence to the contrary, that we ourselves are causal machines. Although Churchland doesn’t come out and explicitly affirm this, it is fairly clear from her statement that the brain is a causal machine that this is precisely what we are to infer. Neurophilosophy (being grounded in science) accepts the materialist hypothesis that everything is inanimate, inert ‘stuff’ interacting according to the four fundamental forces of nature, and draws the inevitable conclusions, irrespective of what our subjective, conscious experience tells us. The brain, being made of ‘matter,’ is a causal machine, and so, the mind, ‘emerging’ from the brain (another huge problem science hasn’t shown even the slightest hint of real progress in addressing), is just as causal. How could it be otherwise?

A fuller discussion of precisely what ‘matter’ is, is well beyond the scope of this article, but I would just register my scepticism here that any description of the brain as a ‘causal machine,’ as if it were like any other inanimate, physical object in the universe (perhaps just more complex, different in degree, but not in kind), will ever yield a meaningful, ‘true’ description of human reality.

 

 Morality

Again, I will start out in perfect agreement with Churchland when she says that science can’t tell us what is right or wrong. We can’t stick a person into an fMRI machine and get a moral system displayed on the screen in that little viewing room to the side. Rather, she insists, science brings facts to the table concerning how our brains function, in effect, putting biological constraints on what moral rules are going to make sense for us.

In pursuit of this goal, her and Carroll spend a long time talking about how mammalian mothers first started caring for their offspring. This is an interesting, and, no doubt true, account of how mother nature solved the problem of our warm-blooded ancestors having to eat more than their cold-blooded cousins, by making the former smart. To cut a long story short, there were two ways to do this. The first was instinct; that is, build the smarts into the genes, so that offspring would be born with all of the skills they need ‘hard-wired’ into them. This is effective, but limited in scope. The second way is through learning, whereby offspring are born with few, if any, innate skills, but have the capacity to learn. This is obviously more time-consuming, but incredibly versatile. Needless to say, nature took the second path, and this ‘decision’ meant it needed to find someone to look after the almost completely helpless infant until it had learned enough to survive on its own. Given that the mother happened to be nearby, nature nabbed her for the job. And how did it pay her for her troubles? The chemicals oxytocin and vasopressin.

This is the cue for another story; this time about montane voles and prairie voles. The two species are very similar, but they differ in one important respect; the latter mate for life. In seeking to explain this, scientists discovered that prairie voles had a much higher density of receptors for oxytocin in the reward system of their brains than the montane voles. This was the smoking gun for Churchland. Turn off the oxytocin receptors and monogamy drops; turn them on, and it’s all cuddles and smiles. As Churchland says, it’s causal. How does all of this tie in with morality? Well, all of our morality is grounded in the capacity to care for others. Where did this capacity come from? The oxytocin-infused brains of our mammalian ancestors who passed this trait on to their descendants, and eventually us.

I won’t be questioning the evolutionary science that this story is founded on. The reason is I believe it is essentially correct. As I’ve said many times before, evolution is about as rock solid a theory as you can get. Some of the interpretations and excesses of evolutionary theory are a different matter, but we won’t be getting into those today. Instead, there are three things I want to pick out for further discussion from the preceding. First, as we saw, Churchland claims that this discovery is important for morality because it puts constraints on what moral injunctions are going to make sense for us. Second, she affirms (at some prodding from Carroll) that she is not trying to derive ought from is. This is true, but not in the way you might think. Finally, we need to fully elucidate what it means to say that levels of oxytocin (or the density of oxytocin receptors) in the brain ‘causes’ monogamy.

 

Neuroscience constraining morality

Churchland defends neurophilosophy from its detractors by saying that the research, in this case the discovery that the oxytocin (and vasopressin) ‘high’ is one of the primary drives behind our urge to care for our offspring (and pair bond), helps us with morality because it tells us that a moral code which requires us to sever the bond we have with our offspring, by sacrificing our first born, for example, won’t work. We can’t do it. We’re just not wired that way.

Unfortunately, nothing about this makes any sense to me. In the first place, the neuroscience doesn’t tell us anything about morality that we didn’t already know (our morality ought to include caring for our young, for example). Why? We already knew we cared for our young. Discovering processes in the brain which are correlated with this tendency is, for sure, interesting, and will quite probably turn out to be useful in the future, but it doesn’t tell us anything we didn’t already know about specific moral rules which will and won’t work for us.

Second, it can’t be right that to say that a moral code in which we are required to sacrifice our children won’t work. Sacrifice, including child sacrifice, has been a part of many cultures for most of human history. Furthermore, there is no reason at all to believe that high oxytocin levels in the brain would somehow prevent the acceptance of child sacrifice as a moral/legal duty in a society where this was just accepted as the norm (we have done much worse, contrary to all evolutionary/chemical directives to the opposite, for far flimsier reasons). Indeed, there is no reason not to believe that such a society could actually lead to the suppression of oxytocin in the brains of individual people. Oxytocin would also be powerless to prevent the creation of something like Plato’s Republic, in which children are given to the State to be raised, and parents are deliberately prevented from knowing which child is theirs to encourage them to treat all children well. And wasn’t it oxytocin that made the prairie voles mate for life? Well, married humans somehow manage to thwart this chemical imperative on a disturbingly regular basis, not to mention all of the people who deliberately reject the societal convention (and supposed oxytocin imperative) that says we ought to be monogamous, instead preferring to have open relationships or even polygamous ones. None of this can be explained on Churchland’s model.

This is a good example of how treating human beings as determined, causal machines doing nothing more than enacting the will of their (selfish) genes (or hormones) leads to conclusions that don’t stand up to even the slightest scrutiny. Our behaviours and decisions (including those regarding morality) aren’t causally determined by our genes, our chemical makeup, or even our environment. A materialist framework, like neurophilosophy however, has no option but to endorse such conclusions.

 

Ought from Is

Churchland was a little evasive on the podcast regarding this, I felt. Carroll had to push her a bit to get her to say she wasn’t trying to derive ought from is. If I’m right about Churchland’s hesitance here, the reason, at least, seems pretty clear. The problem isn’t that she is trying to derive ought from is, it’s that the notion of ‘ought’ doesn’t really make sense within the overall picture she is painting. This is a tension underlying Churchland’s whole neurophilosophy project. The brain is a causal machine, and behaviour is determined (oxytocin makes mammals pair bond (along with other influences, I’m sure Churchland would agree, but other influences which are just as causal)). Where is their room for ‘ought’ in that? What happens happens. There is no freely acting self in this (causal-) brain-dominated picture of the mind. We are essentially no different from a leaf falling from a tree. We are composed of the same ‘matter,’ and subject to the same forces. The only difference is that the processes going on in us are more complex. In a universe like this; i.e. one composed of mindless particles interacting in purely deterministic fashion with other mindless particles, the notion of ‘ought’ just doesn’t make sense. Without genuine, spontaneous freedom, you absolutely cannot have an ‘ought,’ and without the capacity to say one ‘ought’ to do this instead of that, or one ‘ought not’ to do that instead of this, you absolutely cannot have morality.

 

Chemicals in the Brain Causing Behaviour

In the podcast, after Churchland reveals the ‘power’ of oxytocin and makes the comment that the brain is a causal machine, Carroll remarks that behaviour is ultimately an expression of what goes on in our brains. Churchland agrees and reinforces this picture with the (quite accurate) observation that we are essentially different people depending on the state of our brain chemistry, and even (in what probably amounts to the same thing) whether we are simply tired, well-rested, hungry, stressed, and so on. How can we make sense of this? Are we simply slaves to our brain chemistry (and other equally causal factors)?

There is no denying that everything Churchland says is true. Behaviour, thoughts, even personality, are all influenced by a million biological factors, over most of which we have no direct control, fluctuating as they do according to genetic predispositions, sugar-levels in the body, the amount of sleep we got the night before, and so on. There is no stronghold deep inside where a fixed, unchanging core personality, an imaginary ‘real’ me, resides. But in rejecting this independent, rational, Cartesian-style cogito, we ought to be wary of swinging the pendulum too far in the opposite direction and affirming that mind must therefore be nothing more than what goes on in the brain, just another link in a causal chain set in motion at the birth of the universe. Yes, my moods vary and this influences my thoughts and my behaviour, but I am not a different person when I am tired. I’m just more irritable, or less positive. Importantly, I am also able to step back from my immediate concerns, realise that I am irritable because I am tired, and then do something about it. The determinist can, of course, simply reply that that ‘realisation’ (to the extent that it makes sense to talk about a lump of matter ‘realising’ anything) is nothing more than the effect of other causes (hormones, genes, other people telling me I am irritable, etc.). This isn’t a completely impossible hypothesis, however, it is first, nothing more than a hypothesis; second, a hypothesis that I just don’t think adequately explains or describes human experience; and third, a hypothesis that seems unlikely to be correct. I just can’t see how or why a non-physical mind (which actually does nothing except generate an illusion of control and involvement) could have evolved from physical, non-mental parts.

It is tempting here to bring to mind extreme examples, and then leap to hasty conclusions about determinism and material causality. I’m thinking in particular of Phineas Gage, whose encounter with an iron rod that buried itself in his head without killing him, left him with quite a different personality than his pre-accident self, or patients with brain tumours that cause them to act in ways completely out of character. No one would doubt that certain, specific changes to the brain can result in such vast differences to the mind associated with it that the person in question is hardly recognisable to friends and family anymore. And yet, it doesn’t follow from this that brain causes mind in the same way that heat causes water to boil. I am not claiming that the mind is somehow impervious to changes in the brain, even extreme ones that completely alter it; all I’m asserting is that if you have a mind, you have a whole that, in some important and significant ways, transcends the parts of which it is comprised.

 

In this section, I have gone fairly far afield from the direct discussion in the podcast, but not without reason, I think. There is a definite, strict materialist, deterministic undertone to the way Churchland talks about morality, monogamy, and mind with Carroll. She is careful to acknowledge that, although the oxytocin story of morality is “significant,” it isn’t the whole story, and I am certain she is neither reducing human behaviour to neurochemistry, nor denying the influence of external, environmental factors. However, I do think it is fairly clear that Churchland believes mental phenomena reduce to brain phenomena (which is why she is so excited about neuroscience; because it explains the mind causally), and I cannot see how this can be true while at the same time preserving what we know about our conscious experience. A huge piece of the puzzle is missing here, and it can’t just be another piece like all the others. The change I am envisioning here will require a complete rethink of our picture of reality, including, importantly, matter itself.

 

Freewill

Carroll asks Churchland directly about her position on freewill, and gets a very unsatisfying answer (to me anyway). Instead of saying freewill is an illusion, which is, I think, the only conclusion that makes sense in a neurophilosophical framework, she equivocates on the meaning of the word ‘freewill.’ The issue of freewill is only interesting for Churchland in regard to responsibility, which is to say, holding people accountable for their actions in a legal sense, so we can prosecute them when they deserve it. What shifts an action from my-brain-made-me-do-it unaccountability to full-on moral responsibility is forethought. If an action requires sustained effort over some length of time, deliberation, and planning, then this is sufficient for Churchland to call it ‘free.’

This is all well and good, but has obviously dodged the question, which was about metaphysical freewill; i.e. do we have spontaneous freewill or is everything we do determined? Churchland may genuinely find this question uninteresting, or perhaps unanswerable, but it is nevertheless valid. It is also quite obvious what neurophilosophy has to say on the subject; namely, we are strictly determined. The problem then is how do we get any kind of responsibility out of what is clearly a determinist framework? Churchland says that it won’t do for someone who has planned and deliberately intended some action to claim that their brain made them do it. Why not? Mind emerges from the brain, and the brain is a causal machine. I’m not sure why planning and forethought should suddenly turn an author-less causal machine into an agent-driven one in which it makes sense to talk about moral responsibility. If the presence of certain chemicals in my brain makes me a faithful partner, I don’t see why the absence (or presence) of certain (other) chemicals wouldn’t make me a thief, a huckster, or a psychopath.

 

The Philosophical Community’s Reaction to Neurophilosophy

According to Churchland, philosophers aren’t particularly sympathetic to neurophilosophy. It isn’t hard to see why. As I’ve argued above, knowing what is going on in our brains (the neuroscience aspect), while certainly interesting and likely to be of medical benefit at some point in the future, doesn’t help us even a little bit with our morality, or our understanding of the mind (the philosophical aspect). Even worse though, is what neurophilosophy suggests about us. If neuroscience does explain the mind in the way Churchland is suggesting, then the mind is, in fact, nothing more than a causally ineffective, meaningless, by-product of the only thing actually happening; i.e. non-mental, physical events in the causal machine we call a brain. And this, I suspect, is precisely why philosophers don’t have much time for neurophilosophy; because in reducing the mind to the brain, Churchland is actually denying that philosophy has anything substantive to contribute to the conversation. What would be left for philosophy to do if mind is explained by the brain? Neuroscience would be the beginning, middle, and end of research/discussion about the mind. Philosophy might be called on to interpret the findings of neuroscience, or point out further interesting avenues to explore, or clarify hypotheses, but this would be such a diminished, pathetic version of philosophy that I can’t imagine any philosopher finding value in it.

It might sound a little like I’m just arguing that if neurophilosophy were right, actual philosophy would be reduced to some pathetic shadow of its former self. Boo hoo. How sad. Let’s not let that happen. If that were my argument, you would be right to turn tail, and run a mile from the ideas in this article. In fact, if that were true, I would give you a pair of running shoes and a head start. Rather, what I’m saying is that neurophilosophy isn’t actually any kind of philosophy. It’s pure neuroscience, coupled with a re-interpretation of philosophical issues (morality, freewill, etc.) in neuroscientific terms (hormones, neurotransmitters, DNA, and so on). And I’m not arguing, “Oh no, how sad for philosophy.” I’m arguing that mind is not reducible to the brain, and behaviour is not ultimately an expression of what goes on in the brain. Philosophy then, is important, and we should work to preserve it, not out of some misguided respect for the tradition, but because it is the only tool we have for investigating the mind and mind-related issues. Reducing monogamy to oxytocin (and other causal influences) will never get at the heart of this tendency, or any other characteristic, belief, or action we might wish to understand.

In the podcast, Churchland implies that philosophers are resistant to neurophilosophy because they are somewhat old-fashioned and territorial, and being unable to adapt, feel threatened by this wave of change. Carroll sympathises, expressing hope that the new generation will be more open to this interdisciplinary approach. For my money, I hope Carroll is wrong. Neurophilosophy is a wave of change, but rather than being interdisciplinary, it seems to me to be more of an absorption of the ‘philosophy’ into the ‘neuro.’ And this is why philosophers don’t like it.

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