My first argument for the (CRT) attempts to establish that folk psychology contains obligation-satisfying clauses like (OS) from Chapter 2, which again says that a subject who believes that P will believe many of the things she ought to believe given P. The first premise of the argument is (P1).
(P1): Some mental states, and belief in particular, possess some of their actual causal powers essentially.
(P1) will of course be accepted by causal functionalists, and in fact I’m counting on the same sorts of considerations that generate support for causal functionalism to support (P1). That being said, I believe that (P1) should be accepted even by philosopher who think causal functionalism is wrong and that there’s more to mental states than the causal relations they enter into.
Try to imagine a possible token of the belief that snow is white which possesses none of the causal powers that go with this belief here in the actual world, but instead possesses the causal profile that here in the actual world goes with being a pain, or with being a copper atom, or with being a gunshot. I claim that such belief tokens are impossible – inconceivable, even – and that the reason this is so is because at least part of what makes a belief a belief is the causal powers it possesses. A philosopher who rejects causal functionalism can agree with this verdict, she just needs to insist that there is also an additional component to belief’s essence – perhaps a normative one, perhaps a phenomenal one, perhaps one of some other sort.
Taking (P1) as having been established, then, let’s now focus on belief’s causal profile here in the actual world. Which of belief’s actual causal powers does it possess essentially? The powers that comprise belief’s actual causal profile can be divided into three mutually exclusive and exhaustive categories: (i) irrational powers, that is, powers whose exercise exhibits irrationality on the part of the believer; (ii) arational powers, that is, powers whose exercise exhibits neither irrationality nor rationality on the part of the believer; and (iii) rational powers, that is, powers whose exercise exhibits rationality on the part of the believer. I now will argue that though here in the actual world belief possesses powers belonging to each of these three categories, it is only belief’s rational powers which belong to its causal profile essentially.68
To make this case, let’s start by focusing on belief’s actual irrational powers. Now, a number of irrational powers are known to belong to belief’s actual causal profile without the aid of serious scientific investigation. For instance, it doesn’t take serious science to know that people occasionally deny the antecedent. Or, to put the point explicitly in terms of belief’s causal powers: it doesn’t take serious science to know that a subject’s believing that if P then Q and that ~P can sometimes cause her to form the belief that ~Q. When this causal power is exercised, a specific form of theoretical irrationality is exhibited by the subject of the beliefs, which is why the power in question is categorized as an irrational power. To shift from theoretical to practical irrationality, it doesn’t take serious science to know that subjects occasionally succumb to weakness of will. In cases of weakness of will, a distinct irrational power of belief is exercised, a power to interact with desires in a certain way in producing intentions and, subsequently, actions.
Again, both of these are examples of irrational causal powers we know belief to actually possess without the aid of science. A number of irrational powers are known to belong to belief’s actual causal profile only thanks to recent empirical investigations of irrationality, however. For instance, the psychologists Amos Tversky and Daniel Kahneman have documented in detail people’s susceptibility to the conjunction fallacy, best known from their well known experiment involving Linda.69 In the experiment, subjects are given a description of Linda stating that, inter alia, she participated in antinuclear demonstrations as a student and was deeply concerned with issues involving discrimination and social justice. The subjects are then asked to rank the probability of various propositions. In overwhelming numbers, they judge that the proposition that Linda is a bank teller is less likely to be true than is the proposition that Linda is a bank teller and is active in the feminist movement. But, this judgment is irrational since the latter proposition is a conjunction containing the former proposition as one of its conjuncts – the latter proposition can’t be true unless the former is.
We can think of Tversky and Kahneman’s experiment as empirically revealing that belief possesses a certain causal power, a power which is exercised when subjects commit the conjunction fallacy. Granting that the conjunction fallacy really is a form of irrationality, this power belongs to the category of irrational powers. It is along these lines that I propose to understand the voluminous psychological findings regarding other forms of irrationality as well, including base rate neglect, the susceptibility to framing effects, risk-aversion, and so on.70 That is, I interpret this work as empirically revealing more and more irrational powers belonging to belief’s actual causal profile.
Thus, belief actually possesses many, many irrational causal powers. Do these irrational powers belong to belief’s causal profile essentially, though? I claim they do not. For, consider a state F at a possible world w such that F’s causal profile at w is just like belief’s causal profile here in the actual world, except that F at w doesn’t possess any of the irrational causal powers that belief actually possesses. Subjects in F at w, then, never do the equivalent of denying the antecedent or succumbing to weakness of will; they never do the equivalent of committing the conjunction fallacy; etc.71 On the other hand, since F at w possesses all of belief’s non-irrational causal powers, subjects in F at w do do the equivalent of carrying out rationally justifiable inferences and acting rationally, in much the way we do. Thus, there is some amount of overlap between F’s causal profile at w and belief’s causal profile here at the actual world, but there are also many differences. The question is, are the causal differences enough to disqualify subjects who are in F at w from thereby being in belief states?72
It seems completely clear to me that the intuitive answer to this question is No. It seems to me that this should be absolutely uncontroversial: a subject who is insusceptible to the forms of irrationality that we are still could be a believer. If anything, I’m almost inclined to hold that subjects in F at w are better qualified to count as believers than we are. Leaving this stronger claim aside, if I’m right and the causal differences between F at w and belief here in the actual world fail to disqualify subjects in F at w from thereby being in belief states, then it seems to follow that those causal powers possessed by belief here in the actual world but lacked by F at w – that is, all of belief’s actual irrational causal powers – are not essential to belief. This conclusion is what I had hoped to establish in this subsection.
The argument just presented doesn’t appear to turn on the point we noted in Chapter 2 in connection with Lewis’s treatment of near realization, the point that no very specific causal power seems to be essential to mental states. For, first, we aren’t dealing with a very specific causal power in the present argument, but rather with a broad range of causal powers. If the thought experiment I’ve presented is successful, what it shows is that even if a possible state is missing each and every irrational causal power in belief’s actual causal profile – and again, there are many, many such irrational powers – this by itself isn’t enough to disqualify subjects in that state from thereby being in belief states. Second, it seems to me that in cases of near realization, I feel a kind of mild intuitive pull that is altogether lacking here. Could there be, say, an intention to wiggle one’s toes that completely lacked the power to cause one’s toes to wiggle? I suspect that there could be if a near realization scenario were involve – that is, if the state possessed enough of the other causal powers that typically go with intentions to wiggle one’s toes. That being said, I do feel at least a little bit of an intuitive pull toward saying that any state lacking this causal power is, ipso facto, not really a toe wiggling intention. In the present case involving belief and irrational causal powers, however, I feel not even the slightest bit of pull toward saying that, because of the causal differences, subjects in F at w are disqualified from thereby being in belief states.
Before moving on, I want to say a few more things about the (CRT) and irrationality. The first point to make is that the conclusion I’ve reached here, that irrational causal powers don’t belong to belief’s causal profile essentially, doesn’t in any straightforward way undermine the interest of empirical research on irrationality. Even if one is generally sympathetic to the thought that science discovers essences, one is going to need to allow that this isn’t all that science does. At least some of science’s discoveries aren’t discoveries of essences. According to the conclusion I’ve argued for in this subsection, the psychological discoveries regarding human irrationality fall into this category.
More than this, though, I believe that the views I’ve defended in this subsection fit naturally with how typical empirical researchers of irrationality understand their work. The heuristics and biases program initiated by Tversky and Kahneman takes as one of its starting points the idea that because the real world imposes limitations on human beings of time, resources, computing power, and so on, human minds should be expected to have hit upon quick-but-dirty heuristics which generally produce rational results but which are inevitably subject to certain biases.73 So, for instance, what Tversky and Kahneman take human beings’ susceptibility to the conjunction fallacy to reveal is that in our reasoning, we employ a representativeness heuristic74 which generally can be counted on to produce rational results but which in certain circumstances, like that created for subjects participating in the Linda experiment, yields predictably irrational results.
Minds facing different sorts of limitations of time, resources, computing power, and so on – perhaps minds facing different selection pressures in their evolutionary histories, for instance75 – might well hit upon different sorts of heuristics than the ones our minds have, resulting in different patterns of irrationality than the ones we fall into. Perhaps in the limit, a mind facing absolutely no limitations of time, resources, computing power, and so on, wouldn’t need to settle for quick-but-dirty heuristics, but instead would be able to achieve perfect rationality. At any rate, no small part of the interest in research on irrationality is guided by the thought that a good way to find out which of the indefinitely many heuristics we might conceivably be employing in our reasoning – each of which is compatible with our general rational acumen – is to determine the forms of irrationality we systematically fall into. By its biases, a heuristic is known.76
A natural way of incorporating these thoughts into our metaphysics of mind is to hold that these empirically discovered irrational powers belong to belief’s causal profile contingently, not necessarily. Minds employing alternative heuristics could then still be in belief states even though they aren’t prone to the same systematic forms of irrationality our minds are – even though they are perhaps prone to their own systematic forms of irrationality.77 In light of this natural way of viewing things, I don’t want to claim merely that my above conclusion, that belief’s actual irrational causal powers aren’t essential to it, is compatible with empirical research on irrationality. Rather, I want to make the stronger claim that my above conclusion is supported by such work, at least insofar as its interpreted broadly along the lines suggested by researchers belonging to the heuristics and biases program. Think of this as a challenge, then, to those philosophers who would deny the present subsection’s conclusion: can they square their view with empirical research on irrationality?
The other point I wanted to make before moving on is that neither the letter nor the spirit of the (CRT) is compromised by supposing, as I have here, that actual people are irrational in many, many ways. For my purposes in this work, I’m willing to suppose that the standards of rationality that subjects must meet to qualify as believers are relatively low. Now, it may be that this sort of “minimal rationality” view, in Christopher Cherniak’s phrase,78 is not robust enough to sustain all the arguments that those philosophers associated with constitutive rationality want to make. For instance, Cherniak claims that Davidson’s objection to the “very idea” of conceptual schemes79 requires that there be fairly high standards of rationality that all possible believers must meet.80 Regardless of whether or not Cherniak is right on his reading of Davidson, none of the arguments I’ll be making in this work require standards of rationality that are all that strong.
To anticipate myself a bit, in Chapter 4 what I’ll be arguing is that mental properties are themselves normative, and that because normative properties are generally irreducible to non-normative properties, it follows that mental properties are irreducible to physical properties. As we’ll see, the irreducibility thesis about normative properties I’ll be defending is similar to G. E. Moore’s non-naturalism in metaethics in certain respects.81 Now, for many philosophical purposes, the difference between, say, being saintly and merely being kinda good may matter quite a bit. With respect to Moore’s non-naturalism, however, the difference between these two properties isn’t especially important. If non-naturalism is correct, then neither of the properties will be reducible to non-normative properties. Analogously, for the purposes of the antireductionist argument I’ll be making, it won’t really matter whether the rational obligations a subject must meet to qualify as a believer require that subject to be rationally saintly, so to speak, or whether they require here to be merely rationally kinda good.
If (P1) is true then belief possesses at least some of its causal powers essentially. But, as I just argued, it doesn’t possess any of its actual irrational powers essentially. Thus, all of its essential powers must be either arational or rational powers. In the present section I will be arguing that none of belief’s actual arational powers are essential to it.
What are examples of belief’s actual arational powers? Here are some plausible candidates. Believing that embarrassing information has just been revealed about oneself can cause one to blush. Believing that there will be many Christmas presents to open in the morning can cause a child to have trouble sleeping. Believing that one’s life is in immediate peril can cause one to lose one’s appetite. Each of these powers is known to belong to belief’s actual causal profile without the aid of serious science, but consider the placebo effect, which was discovered only through medical research. On the conventional understanding, what the placebo effect involves is a subject’s belief causing her medical condition to improve. For instance, a subject’s belief that the sugar pill she’s been taking is medicine causes her headaches to become less frequent and severe.
In each of these examples of powers belonging to belief’s actual causal profile, it seems plausible that the exercise of the power in question exhibits neither rationality nor irrationality on the part of the believer. It seems plausible that it is neither rational nor irrational to blush, to be unable to sleep, to lose one’s appetite, or to fall prey to the placebo effect. Is there anything else that unites these arational causal powers? Clearly there is. Each of the powers in question is a power to produce a bit of behavior that does not qualify as an intentional action. Blushing, being unable to sleep, losing one’s appetite, and falling prey to the placebo effect are not actions that subjects perform, they are things that happen to subjects. That this turns out to be the unifying feature bonding the disparate examples together is not a coincidence, I take it, given that we’re presently restricting our focus to belief’s arational causal powers. For actions are the sorts of things that are rational or irrational, at least in the minimal sense of either serving or failing to serve a subject’s desires, given her beliefs. Thus I take it that all (or at least many) of belief’s actual powers to cause action fall outside the category of arational powers, belonging either to the category of irrational or rational powers.82
Thus far, each of the examples of an arational power we’ve considered has been a power to cause behavior as opposed to other mental states. Let’s now shift our focus. It seems plausible that when certain transitions in thought are made, those transitions exhibit neither rationality nor irrationality on the part of the thinker. For instance, a French author’s occurrent belief that the madeleine he’s tasting is delicious might cause him to recall memories of his childhood in Combray. A fraternity pledge’s belief that he’s about to be branded with a red hot iron might cause him to experience as hot (at least for a moment) the ice cube to which he’s exposed instead. In these and other similar examples, it seems plausible that the exercise of the causal power in question exhibits neither rationality nor irrationality on the part of the subject. Neither making Proustian leaps of thought nor having one’s anticipations color one’s subsequent experiences seems either rational or irrational.
Is there anything else that unites these causal powers? There is. Each of the mental-to-mental transitions we’ve just considered is not an inference. Again, this doesn’t seem to be a coincidence. For inferences, like intentional actions, are the sorts of things that are rational or irrational. Thus, as in the case of powers to cause actions, I take it that all (or at least many) of belief’s actual inferential causal powers fall outside the category of arational powers.83
Given this setup, I’m now going to run the same sort of argument I ran in the previous subsection in connection with irrational powers. Consider a state G at a possible world w’ such that G’s causal profile at w’ is just like belief’s causal profile here in the actual world, except that G at w’ doesn’t possess any of the arational powers that belief possesses here in the actual world. G states at w’, then, never cause blushing, or trouble falling asleep, or the loss of appetites, or the equivalent of the placebo effect. G states at w’ also never cause the sorts of non-inferential leaps between mental states that beliefs actually cause. On the other hand, G states at w’ do cause both the equivalents of actions and inferences, both rational and irrational, in just the way that beliefs cause actions and inferences here in the actual world.84 Thus, there is some amount of overlap between G’s causal profile at w’ and belief’s causal profile here in the actual world, but there are also causal differences. The question is, are the causal differences enough to disqualify subjects who are in G at w’ from thereby being in belief states?
Again it seems completely clear to me that the intuitive answer to this question is No. Once again, this strikes me as being about as intuitively clear as these things tend to get. I don’t want to suggest that the powers to cause behaviors that aren’t actions and to cause leaps of thought that aren’t inference are somehow unimportant or uninteresting aspects of our actual beliefs. Our mental lives surely would be importantly different without these powers. That being said, the powers in question strike me as literally inessential. If tomorrow we discovered Martians and learned that they were capable of the equivalent of rational and irrational action and inference, but incapable of blushing or having troubles sleeping or losing their appetites or etc., it would be crazy to take these incapabilities to show that Martians aren’t genuine believers. And so, as I did with respect to irrational causal powers in the previous subsection, I conclude that none of the arational powers in belief’s actual causal profile are essential to it.
The conclusions of the two preceding subsections jointly entail the second premise of my argument for the (CRT).
(P2): Every actual causal power that is essential to belief is a rational power.
Together, (P1) and (P2) entail that at least some of belief’s actual rational causal powers are essential to it. This strikes me as extremely plausible. To make an independent case for this conclusion, let’s return to the style of argument I’ve been using in the last two subsections.
Consider a state H at a possible world w’’ such that H’s causal profile at w’’ is just like belief’s causal profile here in the actual world, except that H at w’’ doesn’t possess any of the rational causal powers that belief possesses here in the actual world. H states at w’’ never cause the equivalent of rationally justifiable actions or rationally justifiable inferences, then, as our beliefs sometimes do. On the other hand, H states at w’’ do sometimes cause their subjects to do the equivalent of committing the conjunction fallacy; they do sometimes cause their subjects to blush; and so on, for all of belief’s actual irrational and arational causal powers. Thus, there is some amount of overlap between H’s causal profile at w’’ and belief’s causal profile here in the actual world, but there are also many differences. The question is, are the causal differences enough to disqualify subjects who are in H at w’’ from thereby being in belief states?
Anyone who thinks (as I do) that causal functionalism is at least remotely plausible with respect to belief will be under pressure to give a Yes answer to this question, given the conclusions reached in the last two subsections. But even if one ultimately rejects causal functionalism (as I do), it seems to me that Yes is clearly the intuitively correct answer. A capacity for rational action and inference strikes me as a nonnegotiable, essential aspect of being a believer. Subjects in H states at w’’ don’t have this capacity (or, at least, they don’t have it by virtue of being in H states), and thus they are missing something essential to being a believer. Thus, I conclude, H’s causal profile at w’’ does indeed differ from belief’s causal profile here in the actual world in ways that disqualify subjects who are in H at w’’ from thereby being in belief states. And this shows that some of belief’s actual rational causal powers are essential to it.
Now, that all of belief’s essential causal powers belong to the category of rational powers is not inconsistent with all views that reject the (CRT). For instance, it’s not inconsistent with the causal functionalist view we considered in the introduction to this chapter, the one that rejects the (CRT) even while it agrees with it about which mental states are possessed by all possible subjects. A philosopher holding that view can consistently maintain that the only causal powers that are essential to belief are those which we’ve been calling “rational powers,” while denying that those powers’ link to rational normativity plays any role in the account of what makes a belief a belief
Consistency is not the problem. The problem is that it seems like a remarkable fact that out of the many, many causal powers that belief actually possesses – powers belonging to each of the three categories we’ve been considering – the only causal powers belief possesses essentially are its rational powers. That this should be so cries out for further explanation: why these and just these powers? Views like that of the causal functionalist we’ve been considering are incapable of giving a satisfactory answer to this question, it seems to me. From the standpoint of this causal functionalist’s view, there wouldn’t appear to be any special reason at all to expect belief’s essential causal powers to belong exclusively to the category of rational powers. If it had turned out that belief’s essential causal powers were sprinkled evenly across the three categories, this would’ve fit her view just as well. Thus, it seems to me, this causal functionalist will need to treat the joint truth of (P1) and (P2) as a kind of coincidence, a fact defying further explanation. It’s just a brute fact about belief’s causal profile that it happens to essentially possess the causal powers that it does.
In contrast, views embracing the (CRT) can provide a natural explanation of the joint truth of (P1) and (P2). If folk psychology contains obligation-satisfying clauses, then subjects will need to satisfy certain rational obligations if they are to enter into belief states. To satisfy these obligations, certain causal powers will need to be exercised, and thus possessed. In particular, powers to cause rationally justifiable actions and inferences will need to be possessed, since these are the powers whose exercise will result in the satisfaction of rational obligations. Thus, if folk psychology contains obligation-satisfying clauses – in which case the (CRT) will be true – it’s inevitable that belief will possess certain rational powers essentially.
But why should belief’s essential causal powers belong exclusively to the category of rational powers? This can be explained by the following view, which entails the (CRT).85 Beliefs, in the first place at least, aren’t really causal states so much as they are normative ones. To the extent that beliefs have any essential causal powers at all, what explains why this should be so is that the instantiation of certain normative properties – like that of satisfying a certain rational obligation – requires the exercise and thus possession of such powers. Thus, when philosophers sometimes say that the mind is a causal system, or, more specifically for the purposes of the present discussion, that beliefs are causal states, it’s not that what they’re saying is wrong so much as that what they’re saying fails to capture the nature of belief at its deepest level. Beliefs are (in the second place) causal states, only because they are (in the first place) normative states.
If something like this view is right and beliefs are (in the first place) normative rather than causal states, then presumably there would be no reason at all to expect beliefs to essentially possess any causal powers other than rational ones. More than this, there presumably would be reason to expect that belief won’t possess any such causal powers essentially. In this way, the view just set out predicts the joint truth of (P1) and (P2). Obviously, I haven’t surveyed every conceivable explanation of the joint truth of (P1) and (P2) in this subsection.86 However, it is hard to envision a significantly different alternative explanation that could convincingly make the joint truth of (P1) and (P2) something that is to be expected, as the explanation just provided succeeds in doing. And so, here is my third and final premise in my argument for the (CRT).
(P3): The joint truth of (P1) and (P2) is best explained by views that accept the (CRT).
Until we’re provided with a better or at least equally good explanation of the joint truth of (P1) and (P2), I think we should accept (P3). But then, via abductive inference, we should infer that the (CRT) is true.
This completes my first argument for the truth of the (CRT). To present everything all together, I’ll set out the argument’s premises and its conclusion one last time to wrap up this section.
(P1): Some mental states, and belief in particular, possess some of their causal powers essentially
(P2): Every causal power that is essential to belief is a rational power
(P3): The joint truth of (P1) and (P2) is best explained by views that accept the (CRT)._________________________________________________________