Often, critics of counterfactual approaches to the causal exclusion problem complain that the counterfactuals in question could be true even while the mental was causally inert.263 In effect, such critics charge that counterfactual approaches of the sort in question fail to come to grips with the true depth of the causal exclusion problem. I will be arguing in roughly the opposite direction. What I want to show is that there are cases in which counterfactuals relevantly like (Sob) or (Beep) are false and yet nevertheless there is mental causation. In effect, my charge is that Yablo takes the causal exclusion problem too seriously. He concedes too much to those who push the problem.
8.2.1 THE EXPANDED GILMORE CASE
I want to try to construct a counterexample to Yablo’s account. For these purposes, let’s suppose that the laws of nature are such that there are exactly four nomologically possible physical realizers of pain: PH, PH*, PM, and PM*. PH and PH* are physical realizers of pain that are found only in human beings, while PM and PM* are physical realizers of pain that are found only in Martians. PH and PH* are physically quite similar to one another, while each is physically quite different from both PM and PM*. Next, suppose that while PH, PM, and PM* all causally necessitate sobbing, PH* does not. In fact, let’s suppose that it is nomologically impossible for a being instantiating PH* to sob.
Given this setup, I claim (Sob) would be false. Gilmore is a human being, and so if he had been in pain but not instantiated PH he would have instantiated PH*.264 But, as a matter of nomological impossibility, subjects instantiating PH* do not cry. Thus, had Gilmore been in pain but not in PH he would not have sobbed. (Sob) is false. Nevertheless, I claim, this gives us no good reason to think that Gilmore’s actual pain, realized as it is by a PH instantiation rather than a PH* instantiation, does not cause his actual crying. If Gilmore’s actual pain causes his actual crying even though (Sob) is false, though, then Yablo’s account of mental causation must be wrong.
Before turning to assess what further conclusions should be drawn in light of the problem I have just posed for Yablo, I want to consider two ways one might try to deny that I have succeeded in constructing a counterexample to his account. Neither of these two ways is very promising, it seems to me.
8.2.2 FIRST RESPONSE
First, a defender of Yablo might argue that I have failed in my attempt to construct a counterexample to his account because I have failed to successfully describe a scenario in which (Sob) would be false. There are different ways one might try to show this. For instance, one might raise broadly causal-functionalist worries about the very possibility of PH* qualifying as a physical realizer of pain, given that it is nomologically impossible for subjects in PH* to sob while it is something like a platitude that subjects in pain sob.265 To quell these worries we can suppose that PH* does an otherwise perfect job at occupying pain’s causal role. PH* instantiations are causally necessitated by tissue damage while they causally necessitate wincing, gnashing of the teeth, “Ouch!” exclamations, etc. The only catch is that subjects in PH* never sob.266 I take it that if PH* does such a near-perfect job at occupying pain’s causal role, the present causal-functionalist inspired objection won’t seem very compelling at all.267
Here is a different way a Yablo defender might try to deny that (Sob) is false in the scenario I have described. She might argue that since PH* does not causally necessitate sobbing, PH* is a comparatively unusual physical realizer of pain. So unusual, in fact, that the nearest world where Gilmore is in pain but not in PH won’t be a world where his pain is realized by PH* (such worlds are comparatively far away). Rather, it will be a world where his pain is realized by PM or PM*. If so, then since PM and PM* causally necessitate sobbing, (Sob) will be true, not false. The core thought behind this objection, then, is that the unusualness of PH* qua realizer of pain trumps the physical similarity between PH and PH* when it comes to determining the proximity of worlds for the purpose of evaluating (Sob).
We can head off this line of defense, though, by simply stipulating that PH* isn’t a comparatively unusual realizer of pain. That is, we can just stipulate that PH* does as well at occupying pain’s causal role as do its other nomologically possible physical realizers. Maybe it is nomologically impossible for subjects in PH to wince, for subjects in PM to gnash their teeth, and for subjects in PM* to exclaim “Ouch!” If so, then contrary to the present line of defense, PH* won’t be a comparatively unusual physical realizer of pain at all.
8.2.3 COUNTERPART GILMORE
I cannot think of another plausible argument for denying that (Sob) is false in the scenario I have described. So then, let’s now consider a second way one might try to defend Yablo from my alleged counterexample. A Yablo defender might concede that (Sob) is false but then contend that this is no problem for Yablo, because the correct verdict in the case is that Gilmore’s pain does not cause him to cry.
I have two arguments against this response. The first turns on Counterpart Gilmore, an intrinsic duplicate of Gilmore’s who inhabits some other possible world. Counterpart Gilmore’s world is as much like Gilmore’s as possible except for the following respect: at Counterpart Gilmore’s world, PH*does causally necessitate sobbing. Now being a Gilmore duplicate, Counterpart Gilmore also has a pain, and his pain is also realized by a PH instantiation, and he also sobs. When evaluated with respect to Counterpart Gilmore’s pain, though, (Sob) will be true, not false. Had Counterpart Gilmore been in pain but not in PH, his pain would have been realized by a PH* instantiation. At Counterpart Gilmore’s world (unlike Gilmore’s world), PH* causally necessitates crying. And so, if Counterpart Gilmore’s pain had instead been realized by PH*, he still would have cried.
On Yablo’s account, then, there is an important causal difference between Gilmore’s pain and Counterpart Gilmore’s pain. Because (Sob) is true when evaluated with respect to Counterpart Gilmore but false when evaluated with respect to Gilmore, it follows that Counterpart Gilmore’s pain is proportional to his (respective) sobbing while Gilmore’s pain is not. And so, on the Yablo account it follows that Counterpart Gilmore’s pain causes the relevant bout of sobbing while Gilmore’s pain does not.
I find it extremely implausible that the two pains could differ in this way however. If the only difference between the two pains is the described difference in the causal laws at their respective worlds – and specifically, what we’re talking about here is a difference in the causal laws governing PH*, a physical property which neither Gilmore nor Counterpart Gilmore is in – then how could the two pains interestingly differ in causal status? We can perhaps add to the rhetorical force of this question by further supposing that neither Gilmore nor Counterpart Gilmore ever in their lives instantiate PH*, or even have a causal interaction with a PH* instantiation. If Gilmore and Counterpart Gilmore are so utterly disconnected from PH*, then I do not see how the causal status of their pains could depend on how things stand with PH* at their respective worlds, as the Yablo account entails.
The argument as I have been presenting it turns on a comparison of intrinsic duplicates from different worlds governed by different physical laws. This form of argument might spark a concern: we do not generally expect that intrinsic duplicates will be causally alike if the causal laws at their worlds differ. I do not think this concern is well founded though. For first, I believe that it really is implausible that Gilmore’s pain and Counterpart Gilmore’s pain could interestingly differ in causal status if the only difference in the laws at their respective worlds concerns a physical property, PH*, from which they are so utterly disconnected. Much of what I have already said is meant to support this.
Second, and perhaps more importantly, essentially the same argument can be reformulated in epistemic terms in a way that eliminates the comparison across worlds with different laws. In the epistemic version of the argument, we are again to imagine that we know of four nomologically possible physical realizers of pain: PH, PH*, PM, and PM*. Suppose also that we know that PH, PM, and PM* all causally necessitate sobbing. What we do not presently know is whether or not PH* does. Maybe the only human beings who instantiate PH* live far away, in a distant corner of the universe. Finally, suppose that we know that Gilmore’s pain is realized by a PH instantiation, and that his pain is accompanied by his sobbing. Given this setup, what we want to determine is whether Gilmore’s pain causes his sobbing.
If Yablo’s account of mental causation is correct, then in order to answer this question we will need to find out that which we do not presently know, whether or not PH* causally necessitates sobbing. To discover that it does would be to discover that (Sob) is true, in which case we ought to conclude that Gilmore’s pain does cause his sobbing. To discover that it does not would be to discover that (Sob) is false, in which case we ought to conclude that Gilmore’s pain does not cause his crying. The same issue which arose in the original modal version of the argument arises again in the present epistemic version: how could the causal status of Gilmore’s pain depend in this way on what we learn about PH*, given how utterly disconnected Gilmore is from PH*?
In certain ways this epistemic version of the argument strikes me as more compelling than the original, modal version. I find that my own intuitions regarding what we ought to conclude if we were to discover certain facts of the sort in question are somewhat firmer than are my intuitions regarding what we ought to conclude from a comparison between intrinsic duplicates at worlds with different laws. Still, the Gilmore/Counterpart Gilmore split, which comes with the modal version of the argument, is especially useful in certain ways, and so in the discussion that follows I will focus more on the modal version than the epistemic one.
Summarizing then, Yablo’s account entails that Gilmore’s pain and Counterpart Gilmore’s pain differ in causal status. I claim that this is completely implausible. Thus, I think we ought to conclude, Yablo’s account must be wrong. What’s more, I take it that if there is any mental causation at all, then it should be absolutely uncontroversial that there is mental causation in the case of Counterpart Gilmore’s pain. But then, since Gilmore’s pain and Counterpart Gilmore’s pain can’t plausibly differ in causal status, we ought to conclude that Gilmore’s pain also causes his sobbing.
8.2.4 THE ABSENCE OF STRICT LAWS
Let me now turn to my second argument against denying that Gilmore’s pain causes his sobbing. One thing that might motivate such a denial is a hankering for strict, exceptionless laws to back causal relations. Pain is not always and without exception accompanied by sobbing at Gilmore’s world, and so there will be no strict, exceptionless psychological law linking pain and sobbing there. If there can be no causation in the absence of such strict laws, it then seems to follow that Gilmore’s pain does not cause his sobbing.
A major problem with this argument in the present context – that is, as part of a defense of a nonreductive account of mental causation – is that it is widely conceded by philosophers of mind that if there are any psychological causal laws at all, they are not strict and exceptionless.268 At best what we can hope to find are ceteris paribus psychological causal laws. Now, perhaps the most influential account of ceteris paribus psychological laws is due to Fodor.269 For the sake of the present point I do not need to commit myself to holding that everything Fodor says is right, or even to holding that ceteris paribus psychological generalizations are best thought of as laws. The point I want to make here is just that the connection between pain and sobbing at Gilmore’s world fits Fodor’s account perfectly.
It seems correct to say that at Gilmore’s world, pain is accompanied by sobbing, ceteris paribus. Sobbing accompanies pain, provided that the pain is not realized by a PH* instantiation. PH* realized pains, then, constitute what have been called “absolute exceptions” to the ceteris paribus generalization that sobbing accompanies pain270 On Fodor’s view, the ceteris paribus character of psychological generalizations is generally to be explained in terms of absolute exceptions of this sort. That is, it’s precisely because there are such absolute exceptions that psychological generalizations hold only ceteris paribus rather than without exception.271
For our purposes, the significance of this point is as follows. Again, it’s relatively uncontroversial that whatever true psychological causal generalizations there may happen to be obtain only ceteris paribus, not without exception. But then, if Fodor’s explanation of why psychological generalizations obtain only ceteris paribus is correct – regardless of whether his broader account of ceteris paribus laws is correct – it follows that the sort of absolute exception we find in the Gilmore case in the form of PH* realized pains is not anything unusual, it’s the rule.
Thus, if we deny that there is any mental causation in the Gilmore case on the grounds that PH* realized pains are not accompanied by sobbing, it’s quite possible that we are going to be forced to deny that there is any mental causation anywhere at all, since it seems quite possible that we will find absolute exceptions for any psychological causal generalization whatsoever. Admittedly, if there is no mental causation anywhere at all, then Yablo’s account does not go wrong by entailing that Gilmore’s pain does not cause his sobbing. This would be a rather pyrrhic victory though. Provided that we want to say that there is at least some mental causation, we had better say that there is mental causation in Gilmore’s case.
At this point I have argued that (Sob) is false and yet Gilmore’s pain causes his sobbing. If this is right, then Yablo’s account of mental causation must be wrong. It cannot be that what really matters for mental causation is whether counterfactuals relevantly like (Sob) are true or false. I now want to show that the underlying problem here lies not with the details of Yablo’s account – not with the specific way in which he uses counterfactuals like (Sob) – but rather with the broader picture with which he seems to be operating.272