A New (I Think?) Objection to Psychophysical Harmony Arguments

Or, a new argument for God if you live in a crazy world where nothing makes sense

Pictured: My brain achieving maximum psychophysical harmony

Over the last few years, there’s been increasing attention paid to an argument for theism from psychophysical harmony. If you’re not familiar with the concept of psychophysical harmony in the first place, or haven’t heard the argument before, a great place to start would be Cutter and Crummett’s fascinating paper on the subject. You can also check out a somewhat simplified presentation from the Christian apologetics channel Apologetics Squared, or read a wonderful set of criticisms from the authors of Naturalism Next. Full disclosure: I agree with most of what’s said in that last document, so I think the argument fails for reasons that other people have already pointed out. But I also have my own issue with psychophysical harmony arguments that I haven’t seen discussed much in the literature or online, so I thought I’d take a second today to lay out another reason why we should be skeptical.

I want to start by making two clarifying points. The first is that not all bizarre, absurd, or unfortunate sets of psychophysical laws are necessarily disharmonious. For example, a world where everyone experiences nothing but intense pain every moment wouldn’t be disharmonious, as long as the people in that world respond appropriately by doing nothing but writhing in agony all the time. Or you can imagine a world where stubbing your toe makes you taste strawberries, and people in that world are always stubbing their toes for fun and saying “Mmm, delicious!” afterwards. That’s definitely a weird world, but it’s not disharmonious, because people in that world are responding in normatively appropriate ways to their (weird) psychological states. In order to qualify as actually disharmonious, there needs to be a normative incongruence between the public actions of agents and their internal mental world. And this requires that their actions appear at least somewhat rational or intentionally ordered “from the outside.” Otherwise, there would be nothing for their psychological states to be disharmonious with.

Secondly, I want to point out that psychophysical harmony arguments involve comparisons between worlds, and not just discrete situations or events. In all the materials I’ve seen that present the argument from psychophysical harmony, including Cutter and Crummett’s original paper, the analysis is done almost entirely in terms of specific instances of disharmony: Someone seeing something green while reporting it as red, someone burning their hand while feeling pleasure, whatever. There’s nothing inherently wrong with this - it’s not like I expect anyone to sketch out an entire alternate account of disharmonious humanity - but it does seriously obscure what we’re being asked to accept, for reasons I’ll go over in a moment. For right now, I just want to remind everyone that the disharmonious worlds we’re contrasting with our own are ones with extended histories that involve billions of distinct agents acting in exceeding complex ways, not just isolated instances of single actions by individual agents.

To avoid losing sight of these considerations, I think it’s best to make our paradigmatic disharmonious world one in which all the events throughout that world’s history are identical to events throughout our own world’s history, but with the psychological states of the agents involved being consistently “scrambled” in some way. Obviously, it would be impossible to fully describe every detail of a world like that in a way that would make it useful as an example. But we can at least move away from looking at decontextualized instances of individual behavior and towards extended interactions between agents, and then hopefully we can scale our intuitions about those cases up to consider hundreds of thousands of years’ worth of them. So from here on out, I’m going to focus on a simple exchange I’ve made up, which I’ll call H1:

H1: A man is standing in line at a movie theater. He hears an employee call out “Next!” and walks to the counter. He sees the list of movies playing, considers which one he wants to see, and says he wants one ticket for a particular movie. The employee hears his request, sees the button to print that ticket, and hits that button. He sees the ticket come out of the printer, grabs the ticket, and hands it to the man. The man sees him extend the ticket, grabs it, and turns to walk towards the theater listed on the ticket. The employee sees him walking away and says, “Excuse me, you need to pay for that.” The man hears the employee say this, turns around, and says, “Oh, I’m sorry, I forgot that I didn’t pay online.” The employee hears him say this and responds by saying “No problem, a lot of people are paying online nowadays” before telling him the price of the ticket. The man hears the price and reaches into his wallet, where he grabs enough cash to pay for it.

Now we can imagine this exact exchange occurring in a disharmonious world with all sorts of bizarre psychophysical laws. Call it D1:

D1: A man is standing in line at a movie theater. He sees the color blue and walks to the counter. He smells toast burning, remembers the date of the Battle of Gettysburg, and says he wants one ticket for a particular movie. The employee feels excruciating pain, hears a low rumbling noise, and hits that button. He sees a glowing red orb, grabs the ticket, and hands it to the man. The man feels sandpaper rubbing gently on his back, grabs it, and turns to walk towards the theater listed on the ticket. The employee experiences the sensation of moving at two hundred miles an hour and says, “Excuse me, you need to pay for that.” The man hears Solsbury Hill by Peter Gabriel, turns around, and says, “Oh, I’m sorry, I forgot that I didn’t pay online.” The employee smells gasoline and responds by saying “No problem, a lot of people are paying online nowadays” before telling him the price of the ticket. The man tastes soap and reaches into his wallet, where he grabs enough cash to pay for it.

I think almost everyone will agree that in H1, the harmonious psychological states of the two agents involved explain their actions very well. (If you’re an epiphenomenalist who thinks no psychological states ever explain any actions, then just hold on until the end for your own version of the problem.) We should also agree that, in D1, their disharmonious psychological states don’t explain anything. They can’t, because the defining feature of a disharmonious world is that the normatively appropriate states that would properly explain these actions are gone, replaced by new states that necessarily lack that relationship. So when the employee feels excruciating pain and prints the ticket, the fact that he prints the ticket can’t possibly be explained by the fact that he felt excruciating pain; it’s exactly the fact that feeling excruciating pain doesn’t meaningfully explain printing a ticket that marks out D1 as disharmonious in the first place! If it didn’t feel as though there was something “lost,” some element of understanding or coherence that obtained in H1 but not in D1, then legitimate disharmony wouldn’t even enter the picture.

But if the psychological states of disharmonious agents necessarily fail to explain their actions, is it even conceivable that they would cause them? I want to be cautious here, but I take the preliminary position that no, it isn’t. You can easily conceive of D1 occurring as a set of sequential events, of course. There’s nothing metaphysically impossible about all these things happening one after the other in the way they’re described. But as Joseph Lawal points out in the fourth section of the Naturalism Next critique I posted at the start, conceiving of two events occurring sequentially is very different from conceiving of one event causing another. Personally, I tend to think that explanation - which, let’s recall, is necessarily absent here - is an essential part of any meaningful claim about causality. But even if you prefer a streamlined Humean account of causation that’s much less demanding, a singular instance of sequential ordering isn’t enough to establish the sort of consistent mental relationship you’d need (especially since that very relationship would be incomprehensible to the actual agents who exist in D1, on account of their incoherent psychological states). And if you’re relying instead on accounts that emphasize counterfactuals, then the situation is almost always going to be radically underdescribed; who knows what the closest possible world in which the employee didn’t feel excruciating pain would be like?

As someone who isn’t particularly devoted to any one theory of causation, I won’t make the firm claim that D1 is actually inconceivable when interpreted as a causal account. But I will say that it’s at least debatable, and that advocates of the argument from psychophysical harmony have to do a lot more work convincing us. I’ll also say that I am confident some examples of psychophysical disharmony are inconceivable, like D2:

D2: A man is standing in line at a movie theater. He smells freshly baked bread and walks to the counter. He smells freshly baked bread, smells freshly baked bread some more, and says he wants one ticket for a particular movie. The employee smells freshly baked bread, smells freshly baked bread some more, and hits that button. He smells freshly baked bread, grabs the ticket, and hands it to the man. The man smells freshly baked bread, grabs it, and turns to walk towards the theater listed on the ticket. The employee smells freshly baked bread and says, “Excuse me, you need to pay for that.” The man smells freshly baked bread, turns around, and says, “Oh, I’m sorry, I forgot that I didn’t pay online.” The employee smells freshly baked bread and responds by saying “No problem, a lot of people are paying online nowadays” before telling him the price of the ticket. The man smells freshly baked bread and reaches into his wallet, where he grabs enough cash to pay for it.

In D2, the psychophysical laws are disharmonious but also radically simplified. D2 requires that the experience of smelling freshly baked bread has the causal power to bring about literally any action any agent ever takes. But this is plainly inconceivable, because no plausible account of causation allows for one thing to cause an extensive array of distinct and contradictory actions extending across the entire history of humanity with zero consistency between cause and effect. So while I’m personally skeptical that causation is conceivable in any disharmonious worlds, I can at least confidently say that any disharmonious psychophysical laws that are legitimately causal have to be isomorphic in some way to the psychophysical laws we actually have, or else the actions agents take in those disharmonious worlds would have to be noticeably simpler than in our own, in which case the argument breaks down.

But this has all been a bit of a digression, because the actual argument I want to make in this piece accepts that yes, it is conceivable that the disharmonious psychological states of the agents in D1 really do cause their behavior, even if they can’t explain it. So let’s recap: The agents in disharmonious worlds act in ways that are seemingly rational (because if they didn’t, there would be no disharmony between their ordered actions and their disordered psychological states), but their psychological states don’t actually explain those acts (because agents are necessarily lacking the sort of normatively appropriate psychological states that would give them legitimate reasons for action). So their psychological states somehow cause them to act as though they had reasons for action, reasons that would be properly given by harmonious psychological states they don’t actually have. It’s almost as if their own behavior is somehow established in reference to a harmonious world that exists just out of frame.

This is, I think, an extremely weird feature of disharmonious worlds that proponents of the argument never seem to explain or even acknowledge! Take the employee in D1, where the smell of gasoline causes him to say “No problem, a lot of people are paying online nowadays.” Obviously, the smell of gasoline doesn’t explain what he said, because the whole point here is that no appropriate connection exists between his actions and his psychological states. But it’s also clear the only thing that could plausibly explain what he said is the fact that he heard what the man said to him right beforehand. The employee, then, is just unimaginably lucky; it just so happens the psychophysical laws are such that they happen to prompt appropriate responses to statements the agent didn’t even hear. And of course the psychophysical laws are also finely tuned in the first place to make the man say “Oh, I’m sorry, I forgot that I didn’t pay online” in response to hearing Solsbury Hill by Peter Gabriel, which is another absurd coincidence. And so on for every other event in the sequence (and every other event in human history, if you consider the world as a whole).

More generally, it has to be the case that the behavior of agents in legitimately disharmonious worlds are always governed by nothing more than a giant set of random, brute associations between psychological states and behaviors that just so happen to produce the seemingly rational behavior exhibited by agents in harmonious ones. To me, this is a prime example of - borrowing from Cutter and Crummett’s original paper - something “extremely lucky, or involv[ing] many striking apparent coincidences.” You can even imagine philosophers in disharmonious worlds grappling with the question of why their actions, though entirely irrational, correspond so well with the reasons that would be given by an entirely different set of psychological states other than their own. (Of course, there couldn’t actually be philosophers in disharmonious worlds, but you get what I’m saying.) Why do disharmonious agents scratch their backs, invest in stocks, and look both ways while crossing the street? Maybe because they see an image of a unicorn, feel the sensation of being tickled, and contemplate the number 4. But why are these brute psychophysical laws such that they happen to result in ordered, seemingly rational behavior that perfectly aligns with a set of normatively appropriate psychological states those agents don’t actually have? I don’t think there’s a satisfying answer here beyond that counterfactual appeal.

Ironically, disharmonious philosophers (again, if they were capable of existing) could get around this dead end by appealing to some external power that considers how rational creatures in a harmonious world would act and then works backward to achieve those behaviors through arbitrarily “scrambling” psychophysical laws. But in case you didn’t notice, this is just an argument for theism from psychophysical disharmony. And while I can’t say whether this sort of argument would be very plausible in a disharmonious world, it does seem like you’d need some account for the inexplicable alignment. The alternative is simply accepting an overwhelmingly long list of unimaginably lucky coincidences, much greater in both number and degree than those our own harmonious world would have to account for.

This sets up an interesting contrast that inverts the fundamental assumption of the argument from psychophysical harmony. In our world, the weirdness to account for is just the simple fact that agents’ psychological states generally prompt normatively appropriate actions. But once you bite the bullet on that one, every derivative example of that harmony becomes immediately explicable. You don’t have to ask why the sound of an employee shouting “Next!” causes someone to approach the counter and why deliberating on the list of movies available causes someone to request a certain ticket and why hearing that request causes the employee to print the appropriate ticket, and so on and so on for every action in H1 as well as every other action throughout the history of humanity. You can just say all those causal relationships are specific examples of a general principle of normative harmony. But in the disharmonious world, you would have to go down the list and ask why it is that these seemingly random psychological states have the causal impact they do in every individual case. And not only do you have to keep asking that question - you also can never get an answer, because the defining feature of a disharmonious world is that there is no answer! You’d just have to accept a new “lucky” brute fact in every case, or else invoke truths about harmonious worlds that your own world is somehow parasitic on.

(Here’s where the epiphenomenalist can come back in for a moment. For them, the harmonious world’s weirdness is that particular psychological states generally occur alongside normatively appropriate actions in a non-causal relationship. But this is still much simpler than having to accept as brute the same non-causal relationship between every individual action and every individual disharmonious psychological state that accompanies it non-causally. I think this is a much easier bullet to bite, because you don’t lose any comparative explanatory value between the two worlds; in both cases, the psychological states are inert when it comes to explaining the actions agents take. But it’s still more parsimonious to account for the sum total of these relationships with a single higher-order normative alignment than with a massive set of arbitrary associations.)

To sum it up: Arguments from psychophysical harmony look out at all possible lawlike relations between psychological states and actions, and (correctly) recognize that only a vanishingly small number are normatively appropriate. From this, they reason that this normatively appropriate relationship is a lucky coincidence that needs accounting for. But they miss that the disharmonious worlds they invoke as a contrast also have their own set of lucky coincidences, specifically the fact that necessarily inexplicable psychological states are perfectly “fine-tuned” to bring about seemingly rational behavior (which, again, disharmonious worlds must have in order to establish a legitimately disharmony). These lucky coincidences could only be brute facts, and the set of brute relations needed to account for all human action across time would be vastly more numerous and vastly more incomprehensible than the single brute fact of general normative harmony that can derivative render rational behavior explicable in harmonious worlds. So it seems not only unnecessary but exactly backwards to identify psychophysical harmony as a problematic datum. Instead, it’s psychophysical disharmony that would cry out for explanation - and with no such explanation even plausibly available!

I’ll close with a simple analogy to drive my point home. You can imagine two simple worlds: In the first world, a baseball flies through a glass window and leaves a distinctive baseball-sized hole, while in the second, the same baseball-sized hole appears in the window after a coin is flipped nearby. Which one of these worlds contains - again, going back to Cutter and Crummett - a correspondence that most appears to be “extremely lucky, or involve [a] striking coincidence?” I would say the second, not the first. It might be puzzling, in some sense, that a world would contain laws producing explicable patterns of cause and effect. But it’s even more puzzling that a world would have effects that are comprehensible only in light of causes that don’t actually obtain. If anything counts as a striking coincidence, then certainly it would be baseball-typical holes being inexplicably generated by objects other than baseballs. So it is with human behavior and psychological states: The only thing stranger than our actions making sense would be if they didn’t.