I recently had a fun YouTube debate on philosophy of mind with Ben Watkins. I’m thankful to Ben for debating, and to Cameron Bertuzzi for moderating. The debate is here, and the slides I used are here. These things always feel like they need to take about twice as long as they actually do, so I have a few further thoughts. I don’t have the time just now to write something explaining the background concepts, so parts of this may not make much sense if you don’t have some experience with philosophy of mind. But I’ll start with an overview of what I take the major points of contention in the debate to have been. I think that might help people who had some trouble following the more technical aspects.
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I basically pursued two main lines of argument. The first, the transplant argument, is contained within the slides above, so I won’t rehash it here. The ultimate takeaway of that argument is supposed to be that reflecting on my nature as an enduring subject of experience shows that I have to be simple and indivisible, and this (pretty much) rules out my being material. Ben’s response to this was to deny that I am an enduring subject of experience at all. He instead endorses a “no self” view, saying that all there is to being me is psychological continuity over time (though, as came out in the debate, I had difficulty seeing exactly what his concept of “psychological continuity” is–contrary to what he said, it didn’t seem to me to be compatible with Parfit’s understanding).
A second argument, which I didn’t frame as an explicitly different argument but which sort of came out over the course of the debate as I learned about Ben’s view, was this: both Ben and I agree that the mental and the physical are distinct. And both Ben and I agree that there are (complicated, and in some ways very arbitrary-seeming) law-like correlations between mental and physical states. However, Ben thinks these are, essentially, brute necessities: they are not self-evident, and (as far as I could tell) they don’t have any deeper explanation. On the other hand, I think these correlations represent contingent psycho-physical laws which are explained by divine action. Therefore they have a deeper explanation. So I think my view has an advantage here by having fewer complicated, arbitrary, unexplained posits (at least, it has an advantage if theism is not otherwise too implausible–admittedly, this implicates many other issues). On my view, theism and dualism are sort of mutually supporting here: together they can provide the best view about about consciousness and its relation to the material world, so this gives us reason to accept both. I think at least part of Ben’s response to this was that, even if this was some advantage, dualism still has problems with mental causation.
This brings us to Ben’s arguments. He cites (I would say) three main kinds of consideration which are supposed to favor the view that the mental, while not reducible to the physical, necessarily supervenes upon it (i.e., there can’t be any mental differences without physical differences). The first kind is an alleged in principle problem with dualistic causation. We can divide this into two parts. One, the interaction problem, asks how it’s possible for an immaterial soul to interact with a material body. My answer to this was that there is no “how” involved: it’s a basic form of causation, which everyone has to believe in for some cases. The other, the pairing problem, asks why souls are paired with the bodies they’re paired with, rather than other bodies. I actually didn’t address this, and say a bit about it below.
A second class of considerations are supposed to pose an empirical problem for dualistic mental causation: essentially, we haven’t observed such causation (though we’ve observed plenty of purely physical causation), and such causation would violate the laws of nature. I made two points in response. One was that, as far as I could tell, this was just as much a problem for Ben’s view as for mine, given that he agrees that the mental is distinct from the physical: irreducibly mental properties or events causing things in the physical world violates causal closure just as much as immaterial substances doing so. The other was just that I wasn’t sure we’d expect to have observed immaterial causation even if it was going on in our brains, so that I doubt this provides much evidence against its occurring.
A third was that the close, law-like correlations between mental and physical states are best explained by a necessary supervenience relation. Here, I made three points. The first was that observing law-like correlations generally doesn’t make us conclude that the correlations are necessary (e.g., the significant majority of philosophers agree that the laws of nature are contingent). The second was really a form of what I called my second strand of argument above: if we say these are contingent correlation explained by divine action, we have less in the way of complicated, arbitrary, unexplained posits. A third was that standard conceivability arguments (involving philosophical zombies, etc.) count against the necessary supervenience thesis.
All that being said, here are a few reflections:
A) I think a pivotal moment in the debate takes place around 56:58-57:45, when Ben agrees that my argument for dualism works if we reject the “no self” view in favor of the view that I am an enduring subject of experience. My argument in the slides was focused on trying to establish that conditional (if we are enduring subjects of experience, then…), since I assumed most people watching would accept the existence of a self (thought of as a subject of experience). But since Ben ultimately granted the conditional, I guess the real action was in the antecedent.
Relatedly: the way I set up the personal identity question in presenting my argument during the debate presupposed that, if I’m a material object, then my persistence conditions are those of whatever material object I am. While I think this is what a materialist should say, this isn’t uncontroversial, and in fact it’s not true on (ordinary versions of) the psychological theory of identity: there, it’s more like being me is an office which could be held by different objects at different times. For the sake of time, accessibility, etc., you always have to sort of smooth over certain things in a context like this. But now I regret having smoothed that over, partly just out of generally not liking to say things that are technically false and partly because the psychological criterion wound up factoring into the debate later.
B) Notice that my “second strand of argument” above counts against Ben’s position (which involves necessary supervenience), but is actually neutral between substance dualism and ordinary forms of property dualism (according to which the connection between physical and mental properties is contingent). Since the debate was billed as being about whether the soul existed, I focused on that. If the debate had instead been primarily about the argument from consciousness for theism, though, I could have merely defended the ordinary, contingent form of property dualism, arguing that, even if mental and physical properties inhere in the same substance, theism is still the best explanation of the correlations between them (including the fact that mental properties are instantiated at all).
This would have sidestepped the self/no-self question, and also would have avoided at least some of Ben’s arguments (e.g., the pairing problem). So, oddly, it may be in some ways easier to get from consciousness to theism than from consciousness to the soul.
C) Later on in the debate, Ben expressed the view that it was implausible to say (as I had) that animals have souls, but we didn’t really have time to get into why he thought that. I wish we had. My argument for substance dualism implies that subjects of experience in general are immaterial souls, and so implies that any animals who have conscious experiences are immaterial souls. (In fact, it also applies to any artificial intelligences that might someday have conscious experiences, etc.) But why should that be a problem? I think the most you can say is that it might be historically unusual in certain ways–but I think this historical tendency was for (epistemically, and often morally) bad reasons.
D) I realized after the debate that, although Ben mentioned the pairing problem a few times, I never directly addressed it. If I had, basically I’d have made the points Andrew Bailey, Josh Rasmussen, and Luke Van Horn make in this paper.
E) I didn’t pursue because I was worried the audience would get lost, but I wish we’d been able to get into whether the necessary a posteriori relations between the mental and the physical which Ben believes in are supposed to obtain between mental properties and functional properties, or between mental properties and specific neurological properties, or what. Basically, my thought is that answering “functional properties” commits you to weird judgments about what sorts of things are necessarily conscious. On the other hand, saying “specific neurological properties” makes these relations much more complicated and arbitrary, so that it’s less plausible to posit them without offering some deeper explanation for them (as I try to do). This seems particularly true when we consider that, to account for multiple realizability, the mental properties will probably have to be supervening of some complicated disjunction of different neurological properties.