Belief as the Power to Judge

Abstract

A number of metaphysicians of powers have argued that we need to distinguish the actualization of a power from the effects of that actualization. This distinction, I argue, has important consequences for the dispositional theory of belief. In particular, it suggests that dispositionalists have in effect been trying to define belief, not in terms of its actualization, but instead in terms of the effects of its actualization. As a general rule, however, powers are to be defined in terms of their actualizations. I thus argue that belief has just one actualization, and that that actualization is a particular kind of mental act that I call a judgment. I explain the resulting view—that belief is the power to judge—and argue that it has some important advantages, not only over other dispositional theories of belief, but also over categorical theories of belief. Since these options are apparently exhaustive, it thus has important advantages over all other theories of belief.

1 Introduction

It is as well to reserve ‘belief’ for the notion of a far more sophisticated cognitive state: one that is connected with (and, in my opinion, defined in terms of) the notion of judgment, and so, also, connected with the notion of reasons.

Gareth Evans, The Varieties of Reference

Recently, a number of metaphysicians of powers have argued, persuasively, that we need to be careful—more careful than we usually are—to distinguish the actualization of a power from the mere effects of its actualization.¹ This point, it turns out, has important consequences for the dispositional theory of belief. Simply put: since a power is to be defined in terms of its actualization, we can create illusory difficulties for ourselves, in our attempts to define a given power, if we mistake a mere effect of its actualization for its actualization itself. But this is precisely what has happened to many defenders of the dispositional theory of belief.

According to what I will call the simple dispositional theory, to believe something is to be disposed to behave in a certain way. For example, to believe that it’s going to rain is to be disposed to carry an umbrella. One familiar problem for this theory is that your belief that it’s going to rain won’t lead you to carry an umbrella if you don’t care to stay dry—or, for that matter, if you don’t have an umbrella, or you prefer rainjackets, or any of an endless number of other things. So it seems that the belief that it’s going to rain is no more the disposition to carry an umbrella than it is the disposition to get wet, or to wear a rainjacket, and so on.

Dispositionalists have tended to react to this problem by liberalizing their theory of belief, concluding that each belief is to be identified, not with a single behavioral disposition, but instead with a fairly large set of such dispositions.² I’ll call this the classical dispositional theory. I want to suggest that the classical strategy of liberalizing the simple dispositional theory is a mistake. The solution, it seems to me, lies in another direction: we need to reject the simple dispositionalist’s questionable assumption that, when (for example) you carry an umbrella because you believe that it’s going to rain, your carrying the umbrella is the actualization of your belief that it’s going to rain, and not a mere effect of its actualization. That leaves us, of course, with the question what the actualization of your belief is. But it does at least determine an alternative general shape that a dispositional theory of belief might take. To put it schematically: on this sort of theory, the belief that it’s going to rain will be the disposition—or rather, as I’ll argue in Sect. 5, the power—to $\phi$. And, when you carry an umbrella because you believe that it’s going to rain, you will be carrying the umbrella, not just because you believe that it’s going to rain (though that will be true), but also—and more fundamentally—because you $\phi$ed.

My aim in this essay is thus to motivate, and begin to develop, a dispositional theory of belief with precisely the shape just indicated. On the view I’ll propose, the belief that it’s going to rain won’t be the disposition (or the power) to behave in any particular way (or range of ways). It will, instead, be the power to judge that it’s going to rain (in a sense of ‘judge’ that I’ll explain in Sect. 6). How your belief leads you to behave in any particular situation will then be explained by appeal to the interaction between your judgment that it’s going to rain and your circumstances and other of your mental acts: other judgments, your desires and intentions,³ and so on. Your carrying an umbrella because you believe that it’s going to rain will thus involve, for example, an appropriate interaction between your judgment that it’s going to rain, your desire or intention to stay dry, and, presumably, your judgment that carrying an umbrella will allow you to stay dry. As we’ll see in Sect. 6, some such interactions will be essential to the nature of judgment, and so, by extension, essential to the nature of belief. But, contra the simple and classical dispositional theories, those interactions that issue in action (and behavior more generally) will not be among those that are essential.

I’ll begin by providing some motivation for dispositionalism about belief quite generally. My argument here will rest on the claim (which I defend in Sect. 2) that it’s possible to believe the premises of even the most obviously valid inferences without believing their conclusions. (The discussion of Sect. 2 will also, crucially, help to clarify what exactly I mean by ‘belief’, and so to identify the specific phenomenon I’m theorizing.) I won’t claim that the dispositional theory of belief is the only theory that can explain this fact. But I will argue (in Sect. 3) that categoricalist (i.e., non-dispositionalist) alternatives face a serious challenge from another direction. I’ll then argue (in Sect. 4) that classical dispositionalism faces a serious dilemma. I take this to suggest, however, not that we ought to abandon dispositionalism, but only that we ought to abandon classical dispositionalism. But, to do so, we need, first, to take seriously the idea that belief is a power, rather than a mere disposition (Sect. 5); and, second, to identify the actualization of that power (Sect. 6).

2 Inferential Ignorance

My argument for dispositionalism rests on the possibility of a certain form of what I’ll call inferential ignorance: believing the premises of a good inference without believing the conclusion. The particular form of inferential ignorance I have in mind is that which arises even with respect to the simplest or most obviously valid inferences. My argument thus rests on the truth of the following principle:

• The Ignorance Principle: It’s possible to believe the premises of even the most obviously valid inference without believing the conclusion.

I want to begin, then, with a defense of this principle.

An important source of resistance to the Ignorance Principle lies in the fact that our ordinary practices of belief-ascription can seem to commit us to the following, conflicting, principle:

• Weak Closure: If you believe the premises of an obviously valid inference, then you also believe the conclusion.⁴

For example, if you know that someone believes both that there are no animals on Mars and that giraffes are animals, you’ll generally assume that she also believes that there are no giraffes on Mars. In fact, you’d likely be quite puzzled if someone were to object to your assumption by saying that, although the person in question does clearly believe both that there are no animals on Mars and that giraffes are animals, it would be rash to assume, without further evidence, that she believes specifically that there are no giraffes on Mars. Of course, this puzzlement need extend only to those cases in which the inference in question is especially obviously valid. There’s no need to assume that we believe all of the logical consequences of the things we believe.⁵ But our ordinary practices of belief-ascription do seem to involve the assumption that belief is closed under at least very obvious logical consequence.

But now consider a different example. Suppose that, on Monday, I schedule an appointment to meet with a colleague—let’s call him Eric—on Friday afternoon. I thereby come to believe that I need to meet with Eric on Friday afternoon. Come Friday morning, I wake up, have some coffee, check my email, and so on, knowing full well that it’s Friday. But it isn’t until lunchtime that I think to myself: Didn’t I need to do something today? Oh, that’s right: I made that appointment to meet with Eric—I need to meet with Eric today. Thus, all morning, I believed both that I needed to meet with Eric on Friday and that it was Friday. But it wasn’t until lunchtime that I finally put these two pieces of information together and came to believe that I needed to meet with Eric today. In other words, it wasn’t until lunchtime that I finally inferred: $\langle$I need to meet with Eric on Friday; today is Friday; therefore, I need to meet with Eric today$\rangle$. And this inference is about as obviously valid as an inference can be.⁶ So it looks like it is possible to believe the premises of an obviously valid inference without believing the conclusion. That is, it looks like belief isn’t closed even under very obvious logical consequence. But then what about the first example?

The short answer is that, initial appearances notwithstanding, it is possible to believe both that there are no animals on Mars and that giraffes are animals without believing that there are no giraffes on Mars—just as it’s possible to believe both that you need to meet with Eric on Friday and that today is Friday without believing that you need to meet with Eric today. For, just as it’s possible to forget that you need to meet with Eric on Friday (which might result in your missing the meeting entirely), it’s possible to forget—at least momentarily—that there are no animals on Mars (or, for that matter, that giraffes are animals). You are, of course, a bit less likely to forget that there are no animals on Mars than you are to forget that you need to meet with Eric on Friday. Hence the usefulness of the second example: it helps to relieve some of the doubts you might otherwise have about the Ignorance Principle. But the Ignorance Principle is of course defensible only if every case is like these two. So it will be worth saying a bit more to dispel the appearance that, if an inference is obvious enough, it won’t be possible to believe its premises without believing its conclusion.

So suppose for a moment that the Ignorance Principle is true, i.e., that it’s possible to believe the premises of even the most obviously valid inference without believing the conclusion. (This means, of course, that it’s possible to believe both that there are no animals on Mars and that giraffes are animals without believing that there are no giraffes on Mars. That might still strike you as implausible, but bear with me.) But now suppose that we define tacit belief in the following way: you believe something tacitly just in case it’s an obvious logical consequence of other things you believe. And suppose we define belief* in the following way: you believe* something just in case either (i) you believe it or (ii) you tacitly believe it. Given these definitions, it follows that Weak Closure* is true:

• Weak Closure*: If you believe the premises of an obviously valid inference, then you believe* the conclusion.

One possibility, then, is that our ordinary practices of belief-ascription are really better described as practices of belief*-ascription, and that, therefore, they don’t commit us to Weak Closure, but only to Weak Closure*.⁷

I think it’s fairly obvious why our practices of “belief”-ascription would typically involve belief*-ascription (or something like it) rather than belief-ascription. For, if someone believes both that there are no animals on Mars and that giraffes are animals, then, even on the assumption that she doesn’t yet believe that there are no giraffes on Mars, it’s nonetheless very likely that, because the inference $\langle$There are no animals on Mars; giraffes are animals; therefore, there are no giraffes on Mars$\rangle$ is so obviously valid, she will form that belief just as soon as it becomes relevant—for example, just as soon as you ask her whether there are, or whether she thinks there are, any giraffes on Mars. So, for practical purposes, at least, it’s just as if she believes that there are no giraffes on Mars, even when she doesn’t. Moreover, in ordinary circumstances, you won’t have any way of knowing whether she had already inferred that there were no giraffes on Mars (i.e., before you asked her), or whether she drew that inference only in response to your question. (Parallel points hold for the second example given above, the example of the Friday meeting—and, of course, for every other relevant example.) So, in practice, it actually makes a lot of sense to ignore the distinction between belief and tacit belief, and so, in effect, to work with the notion of belief*.

My suggestion, then, is that we ordinarily use the word ‘belief’ to express the concept of belief* (or something like it).⁸ I’ve opted for a more restricted use of the word, however, for two reasons. First, the phenomenon I want to theorize is (what I have here called) belief, and not tacit belief or belief*. Second, whatever terminology we employ, it’s clear that, given the above system of definitions (of tacit belief and of belief*) the core of a theory of belief* will be a theory of (what I have here called) belief—since both tacit belief and belief* are defined in terms of belief. So I’m really just reserving the term ‘belief’ for the most fundamental phenomenon in the area.

The foregoing thus serves both to identify my target in this essay—belief specifically, as opposed to tacit belief or belief*—and to show that our ordinary practices of “belief”-ascription provide no good reason to doubt the Ignorance Principle, while there is good reason to accept it: no matter how obviously valid an inference may be, it is always possible to believe the premises without believing the conclusion—because, as we’ve seen, it is always possible that you have not yet (so to speak) “used” your premise-beliefs (“put them together”) to form the relevant conclusion-belief.

3 An Argument for Dispositionalism

My argument for dispositionalism has two parts. The first is simple: dispositionalism provides an elegant explanation of the truth of the Ignorance Principle. The second is more complicated, but amounts to this: categoricalism—the view that belief is a categorical, rather than a dispositional, state (or property)—either (i) has the highly dubious consequence that each belief possesses its actual causal-explanatory powers only contingently or (ii) is forced to posit brute necessities; and since neither of these options is ideal, we have good (albeit defeasible) reason to prefer dispositionalism to categoricalism.

3.1 First Part

Suppose that dispositionalism is true, and thus that a belief is a disposition (or set of dispositions). Then note that, in general, something can be disposed to $\phi$ without actually $\phi$-ing, i.e., without actualizing the disposition to $\phi$. An intact but fragile vase, for example, has the disposition to break, but has not actually broken, and perhaps never will. So, if belief is a disposition, and, more specifically, if to believe the premises of a valid inference is to be disposed (perhaps inter alia) to believe the conclusion, then we can explain the possibility of believing the premises without believing the conclusion simply by noting that it’s possible for someone to be disposed to believe the conclusion, but for that disposition to remain unactualized. And, importantly, this explanation works no matter how obviously valid the inference in question may be.

So consider again the second example I gave in Sect. 2. In that example, there’s a period of time in which I believe the premises, but not the conclusion, of the inference $\langle$I need to meet with Eric on Friday; today is Friday; therefore, I need to meet with Eric today$\rangle$. On a dispositional theory of belief, we can say that, during that time, I am disposed to believe that I need to meet with Eric today, but, because that disposition remains unactualized, I don’t yet actually believe that I need to meet with Eric today. But when, around noon, I think to myself Didn’t I need to do something today?, that thought triggers the disposition, which actualizes itself in the belief that I need to meet with Eric today.⁹

3.2 Second Part

I don’t deny that (at least some) categorical theories of belief can explain the truth of the Ignorance Principle. There is, however, a significant cost to categoricalism. In effect, it takes the Ignorance Principle too far: it implies that there is no essential causal-explanatory connection between distinct beliefs,¹⁰ and so goes much further than simply rejecting Weak Closure.

The crucial initial point here is just that there are some essential causal-explanatory connections between distinct beliefs. In particular, although, as I have argued, thinkers don’t necessarily believe the obvious logical consequences of the things they believe, they do nonetheless tend to believe them. In particular, they tend to come to believe the obvious logical consequences of the things they believe—i.e., they tend to draw the relevant inferences—when those consequences are relevant. The Ignorance Principle simply reflects the fact that a thinker can always fail to form the relevant belief (to perform the relevant inference). But the case of failure is not—and, I would argue, cannot be—the norm. If failure were the norm, inferences would be accidents (in the Aristotelian sense). But inferences aren’t accidents. Inferring is something that thinkers, qua thinkers, do as a matter of course.

Let me take these last points a bit more slowly. What I have suggested, to begin with, is merely that thinkers do tend to believe the obvious logical consequences of the things they believe. (This is the grain of truth in Weak Closure.) I have suggested, in other words, that beliefs have certain causal-explanatory powers. We might then ask what kind of fact about belief this is. And there are, I think, three options: either it is a contingent fact about belief, or it is a brutely necessary fact about belief, or it is an essential fact about belief (i.e., a fact that is entailed by the real definition of belief).¹¹

The most natural view for the categoricalist to take is that a belief possesses all of its causal-explanatory powers only contingently. The reason is simple: a categorical property just is a property that possesses all of its causal-explanatory powers inessentially (in the sense that it does not belong to the essence of that property that it—i.e., the property—possesses any of the causal-explanatory powers that it actually possesses),¹² and the only way to avoid the conclusion that categorical properties possess all of their causal-explanatory powers only contingently is to posit brute necessities—to say, for example, that, although it is inessential to something’s being F that it be disposed to $\phi$, it is nonetheless necessary that anything that’s F is disposed to $\phi$.¹³ The positing of brute necessities is, however, intellectually unsatisfying. In fact, I’m inclined to think that, so long as our best theory in some domain is forced to posite brute necessities, we ought to keep looking for a better theory (which isn’t to say that we’ll ever find one—there could be necessary truths we can’t, or just won’t ever, explain). And, in the present case, there are two alternatives: either deny that the truths in question are even necessary, or treat them as essential and so find an appropriate way to explain them. But because categorical properties possess all of their causal-explanatory powers inessentially, the only alternative open to the categoricalist is to deny that the truths in question are even necessary.

The problem with the view that a belief possesses all of its causal-explanatory powers only contingently, however, is that it implies that a belief could remain the belief it is while lacking all of the causal-explanatory powers it actually has. In fact, by the same token, the view implies that a belief could remain the belief it is while possessing all and only the causal-explanatory powers actually possessed by some other belief; in other words, any two beliefs could simply swap their causal-explanatory powers while retaining their identities as the particular beliefs they are. Though views like this are not without their defenders,¹⁴ they aren’t, on the face of it, terribly plausible.

The fact that beliefs do seem to have at least some of their causal-explanatory powers essentially thus provides us with good reason to suspect that belief may be an essentially dispositional property,¹⁵ in the sense that what it is to believe something is—is essentially—to be disposed to do something. This means that, if the belief that p is the disposition to $\phi$, then you simply can’t believe that p without being disposed to $\phi$, because (note the explanatory claim) being disposed to $\phi$ is essential to believing that p. The remaining question, then, is just whether we can identify an act, $\phi$ing, such that belief can be defined as the disposition to $\phi$.

4 A Dilemma for Classical Dispositionalism

According to the classical dispositional theory of belief, when you carry an umbrella because you believe that it’s going to rain, your carrying the umbrella is an actualization of your belief that it’s going to rain. In order to handle the fact that, on certain occasions, your belief that it’s going to rain may instead lead you to wear a rainjacket, it’s natural, as we’ve seen, to allow that a single belief can be identified with a fairly extensive set of dispositions. On the resulting view, it will be true both (i) that, when you carry an umbrella because you believe that it’s going to rain, your carrying the umbrella is an actualization of your belief that it’s going to rain, and (ii) that, when you wear a rainjacket because you believe that it’s going to rain, your wearing the rainjacket is an actualization of your belief that it’s going to rain. So your belief that it’s going to rain has multiple possible actualizations, one for each disposition in the set of dispositions that’s definitive of the belief.

My central objection to classical dispositionalism is that it can’t actually tell us what a belief is. It thus either fails, or—as we’ll see—turns into a form of anti-realism about belief. The latter is, of course, a live option. But—and this is the important point here—going anti-realist isn’t the only way for the dispositionalist to go.

I just said, in effect, that realist forms of classical dispositionalism fail. The core of this problem comes into view already in the familiar problem mentioned in Sect. 1 and again in the last paragraph but one. If we could say, simply, that to believe that it’s going to rain is to be disposed to carry an umbrella, then we would know what the belief that it’s going to rain is: namely, the disposition to carry an umbrella. (We wouldn’t yet know what, if anything, realizes that disposition, but that’s a separate issue.) But we can’t say that. For it has the obviously false consequence that, necessarily, you believe that it’s going to rain just in case you’re disposed to carry an umbrella. The general problem for realist forms of classical dispositionalism, then, is that they’re really no better off than simple dispositionalism is. Thus, suppose we liberalize the latter, and say that to believe that it’s going to rain is to be disposed to carry an umbrella and to be disposed to get wet and to be disposed to wear a rainjacket, and so on, so that, necessarily, you believe that it’s going to rain just in case you’re disposed to carry an umbrella and you’re disposed to get wet and you’re disposed to wear a rainjacket, and so on. The problem now is the “and so on”: until we have a complete list of dispositions, we don’t have a definition of the belief that it’s going to rain, and so we won’t know what the belief that it’s going to rain is. We only have the idea that it’s something that can, under various different circumstances, lead you to do various different things.¹⁶

At this point, the dispositionalist might go anti-realist. This, I think, is the response offered by Schwitzgebel (2001, 2002, 2012, 2013). According to Schwitzgebel, “[t]o believe that p [...] is nothing more than to match to an appropriate degree and in appropriate respects the dispositional stereotype for believing that p. What respects and degrees of match are to count as ‘appropriate’ will vary contextually and so must be left to the ascriber’s judgment” (2002, p. 253). On this view, we stereotypically associate each belief-ascribing predicate, ‘believes that p’, with a set of dispositions. Whether we say that someone believes that p then depends on how many, and perhaps exactly which, of those dispositions she has, in ways that are determined by the context in which we’re trying to decide whether to ascribe the belief. Though he doesn’t use this terminology, Schwitzgebel is fairly clear that this view amounts to a form of anti-realism about belief. As he says at one point: “once the dispositional profile of the subject is made clear, it is a mistake to think that there is still some further question to be answered, namely, what does the subject really believe?” (2002, p. 266, his emphasis). Questions about belief are thus ultimately abandoned in favor of questions about the dispositions with which belief-ascribing predicates are stereotypically associated.

As an account of our practices of “belief”-ascription, there’s a lot to be said in favor of Schwitzgebel’s view. Unlike Schwitzgebel, however, I’m not ready to give up on realism about belief. I think that there’s something real, and worth calling belief, at the core of the phenomena that we ordinarily describe—fairly loosely, as Schwitzgebel stresses—using the word ‘belief’. Thus, I think it makes sense, in the kinds of cases Schwitzgebel describes, to ask whether the person in question really believes—even if, for ordinary practical purposes, asking and answering this question typically has little, if any, point. The difficulty, for theoretical purposes (and thus for my purposes here), is to say what exactly it is that we (that is, we philosophers of mind) are asking, in asking whether someone really believes something.

5 Belief as a Power

So far, I’ve argued that we have good reason to adopt a dispositional theory of belief, but that classical dispositionalism either fails or turns into a form of anti-realism about belief. We are thus forced back to the fundamental question for the dispositionalist: if belief is a disposition, what, exactly, is it a disposition to do? As we saw in Sect. 1, however, the distinction between the actualization of a power (or disposition) and a mere effect of its actualization suggests an alternative form of dispositionalism, one on which actions like carrying umbrellas are not actualizations of beliefs at all, but are instead mere effects of their actualizations. Since the availability of this alternative can be obscured by a certain permissiveness in the notion of a disposition, we need to begin by distinguishing mere dispositions from what I will call powers. Once we have drawn that distinction, we can then consider the possibility that belief is, not a mere disposition, but, instead, a power. And we can ask, finally, what, exactly, it’s a power to do.

Crucially, a power, unlike a mere disposition, is a sparse or natural property. A mere disposition, by contrast, is an abundant property.¹⁷ Here’s why the difference matters. In rejecting classical dispositionalism, I’ve rejected the view that, when (for example) you carry an umbrella because you believe that it’s going to rain, your carrying the umbrella is the actualization of your belief that it’s going to rain. In doing so, I’ve effectively denied that the belief that it’s going to rain is the power to carry an umbrella. But I haven’t thereby rejected the view that (at least if there are umbrellas, and you know about them, and so on) believing that it’s going to rain disposes you to carry an umbrella. Indeed, on my view, when you believe that it’s going to rain, you will ordinarily be disposed to carry an umbrella. But you will be so disposed because (i) you believe that it’s going to rain, (ii) your belief that it’s going to rain is the power to $\phi$, and (iii) in virtue of possessing the power to $\phi$, you’re disposed (inter alia) to carry an umbrella—because, should you actualize your belief and $\phi$, your $\phi$ing might lead you to carry an umbrella.

Put schematically, then, the idea is that belief just is the power to $\phi$. As such, it will have some of its causal-explanatory powers essentially, namely, those that belong to the act of $\phi$ing itself. Importantly, though, in saying that the act of $\phi$ing “has causal-explanatory powers,” I don’t mean to say that it, too, is a power. It’s not: it’s an act—i.e., a certain kind of event or occurrence. To say that $\phi$ing “has causal-explanatory powers” is essentially just to say that we can explain your doing something—say, $\psi$ing—by appealing to the fact that you $\phi$ed, as in $\langle S \hbox { }\psi \hbox {ed}$ because she $\phi$ed$\rangle$. The result, then, is that there’s one thing that believing that p necessarily disposes you to do: namely, to $\phi$, for an appropriate value of $\phi$. Whatever else believing that p disposes you to do will be explained (in part) by the fact that it disposes you to $\phi$.

Before I explain what it is that I think belief is the power to do, I want to stress two more points about powers, as I understand them. First, powers are to be characterized in terms of their actualizations alone, and not also in terms of their stimulus conditions.¹⁸ Thus, fragility, for example, is the power to break (i.e., to be broken)—full stop. The same is arguably true of dispositions in general, notwithstanding the common assumption (which has its source in the various familiar conditional analyses of disposition-ascriptions) that dispositions are to be characterized in terms of pairs of stimulus conditions and manifestations, as in To be fragile is to be disposed to break (manifestation) if struck (stimulus).¹⁹ This is not to say that powers spontaneously actualize themselves; so this view of powers is compatible with the view that powers are actualized only in the presence of appropriate stimuli. The point is only that the definition of the power needn’t mention stimulus conditions. Which things stimulate a power to actualization is, instead, determined by the nature of its actualization, and the relations that may hold (either essentially or contingently) between its actualization and other events.

Second, as I’ve been assuming, implicitly, throughout, powers are—in terms that descend from Ryle (1949)—single-track. That is, each power has just one actualization.²⁰ Thus, fragility, again, is the power to be broken—full stop. This point is important, because it’s commonly assumed that, if belief is a power or disposition, it must be one with multiple actualizations or manifestations. So, Schwitzgebel (2002, 2013), for example, holds that a belief is a complex of behavioral, cognitive, and phenomenal dispositions, and so has no single characteristic manifestation or actualization. Much of what motivates Schwitzgebel’s view, however, is compatible with the view that belief is a power with a single actualization. For, again, if we distinguish the actualization of a power from the mere effects of its actualization, then we can say that, while there is just one (definitive) actualization of a power, there will, in different circumstances, be a great variety of effects of that actualization. In particular, the behavioral, cognitive, and phenomenal events that Schwitzgebel discusses will turn out to be effects of the actualization of a belief.²¹ Thus, for example, if the fact that you believe that it’s going to rain sometimes leads you to carry an umbrella, that needn’t be because carrying an umbrella is one of many possible actualizations of your belief that it’s going to rain; it may, instead, be one of many possible effects of the single definitive actualization of that belief.

The result, then, is that we’re looking for a definition of belief that has the following form: to believe that p is to have the power to $\phi$. Our only remaining question is thus, again, What is belief a power to do?

6 Belief as the Power to Judge

My suggestion, as I indicated in Sect. 1, is that belief is the power to judge. More precisely:

• Definition of belief: The belief that p is the power to judge that p.

Given the nature of powers, as characterized in the last section, the details of the resulting theory of belief turn entirely on the nature of judgment. So the remaining questions for the theory of belief all concern the nature of judgment. This, then, is the issue I’ll be addressing in this final section.

The theory of judgment I prefer involves a radicalization of Frege’s context principle, which instructs us “never to ask for the meaning of a word in isolation, but only in the context of a proposition” (1884, p. xxii). Although Frege states the principle in apparently linguistic terms, his fundamental point, I think, is about the nature of thought (i.e., cognition). The point is that the components of a thought or judgment are to be explained in terms of the thought or judgment itself, rather than the other way around. As he puts it in a set of notes written in 1919: “I do not begin with concepts and put them together to form a thought or judgment; I come by the parts of a thought by analyzing the thought” (1979, p. 253). In effect, Frege thus proposes to reverse the order of explanation traditionally employed by logicians,²² which began with a theory of terms and proceeded to provide a theory of judgment on that basis, so that judgments were to be understood in terms of terms. On Frege’s view, we are instead to understand terms in terms of judgments. If we make this reversal, however, it makes sense to take it a step further. For the traditional idea was to proceed from a theory of terms to a theory of judgment and then, finally, to a theory of inference, so that inferences would be explained in terms of judgments and judgments, in turn, in terms of terms. But if the context principle instructs us to explain terms in terms of judgments, we might consider taking the next step, and explain judgments in terms of inferences. My suggestion, then, is that we do just that: take inferences as primitive, explain judgments in terms of inferences, and then, finally, explain terms in terms of judgments.

What matters here, however, isn’t the act of inferring in particular, but rather the genus of acts to which it belongs, namely, what I call epistemic acts. An epistemic act is simply an act in which knowledge can be acquired. Epistemic acts, as a genus, are themselves defined in terms of successful epistemic acts, i.e., acts in which knowledge is actually acquired.²³ So the general strategy is to begin with acts of acquiring knowledge, define unsuccessful epistemic acts in terms of them, define epistemic acts generically as the disjunction of successful and unsuccessful epistemic acts, and then define judgments in terms of epistemic acts so defined. The resulting definition of judgment itself is then easy to state:

• Definition of judgment: The judgment that p is the passive component of the epistemic act of $\phi$ing that p.

The definition will, however, require some explication.

In principle, the explication could begin from any epistemic act. In particular, it could begin from the act of inferring. But, because judgments figure in inferences not only as passive components (conclusion-acts), but also as active components (premise-acts), such an explication can seem to presuppose an account of judgment—in which case it couldn’t also provide one. Although I think that this appearance is misleading, I’ll simply skirt the whole issue by beginning, instead, from a different epistemic act, one that doesn’t necessarily involve judgments as active components: the act of perceiving.²⁴ In fact, I’ll use as my central illustrative example a successful epistemic act of perceiving that p, i.e., an act in which you acquire knowledge that p on the basis of perception (of the object of that knowledge).

So, suppose that I have the ability to recognize brown recluse spiders by sight. To have that ability is, of course, to have the ability to acquire knowledge, by sight, that something is a brown recluse spider. What I call an act of acquiring knowledge on the basis of perception—a successful epistemic act of the perceptual kind—is precisely such an act of (re)cognition. Importantly, however, such acts of recognition are not merely perceptual. To see why, suppose that I’m sitting at my computer, answering emails, and that a brown recluse crawls up the wall to a location above and beyond my computer screen. At this point, let’s suppose, the spider is in my field of vision, and I have the capacity to recognize it for what it is. But, intent on writing emails, I might nonetheless fail to notice the spider. If it then crawls back down the wall and disappears, still without my noticing it, I might never know that there was a brown recluse in my office. And yet, when the spider was in my field of vision, my merely perceptual capacities were actualized, in the sense that the spider was, in a certain sense, perceptually present to me: I was, as I’ll put it, in a position to know that there was a brown recluse on the wall. But that actualization of my perceptual capacities is not what I mean by an epistemic act of perceiving (in this case, seeing) that there’s a brown recluse on the wall. The epistemic act is, rather, the act of noticing the spider—or, more fully, the act of recognizing it for what it is (or, in the epistemically unsuccessful case, of misrecognizing it); or, again, the act of acquiring knowledge, via perception, that there’s a brown recluse spider on the wall.

What the example reveals is that, even once I’m in a position to know, by sight, that there’s a brown recluse on the wall—even when I have the ability to recognize it, it’s on the wall, it’s visible to me, it’s in my field of vision, and so on—something (else) still needs to happen: I still need to do something to avail myself of that position and come to know, by sight, that there’s a spider on the wall. In other words, there’s a difference between merely being in a position to know and actually knowing; and coming to know—the act of acquiring knowledge—is the act in which you make the transition from the former state to the latter.

But what, exactly, needs to happen—what do you need to do—to make that transition? Well, here’s how I propose we describe it, in the present case: the actualization of my perceptual capacities (the perceptual presence of the spider to me) needs to cause me to judge, on the basis of that actualization of my perceptual capacities, that there’s a brown recluse on the wall.²⁵ (You might wonder what kinds of thing can make that happen, i.e., what kinds of thing can make me judge that there’s a brown recluse on the wall. Well, here’s one: the spider’s suddenly—noticeably—moving.) Of course, in using the word ‘judge’ here, I’m just providing a label for the thing I thus do, this peculiar effect of the spider’s perceptual presence to me: my noticing the spider (as I’ve put it) and, in so doing, recognizing the spider for what it is and thus coming to know that there’s a brown recluse on the wall. The fundamental point here, however, is just that some such thing definitely happens. And, I claim, we know what it is that happens if we know what it is to acquire knowledge through perception (or, for that matter, in any other way). But, since we do know what it is to acquire knowledge through perception, that just means that we do know what a judgment, in my sense, is: it’s that thing that happens when we acquire knowledge, the kind of thing that noticing a spider (and thereby coming to know, etc.) is. It just takes some work to bring that thing into proper focus. But, once that’s done, we can label it—as, say, a judgment.

The foregoing is an analysis (‘dissection’ might be a better word), in Frege’s sense, of the epistemic act of perceiving that p. What we’ve seen is that such an act can be broken down, dissected, into an active component (a cause), namely, the actualization of my perceptual capacities (i.e., the spider’s perceptual presence to me); and a passive component (an effect), namely, my noticing that there’s a spider on the wall. It is this passive component, this “noticing,” that I call a judgment. Hence my definition of a judgment as the passive component of an epistemic act.

One thing that the act of inferring can then be used to bring into view is the fact that a judgment can, in a certain particular sense, recur. In fact, given the definition of belief as the power to judge, this recurrence can be theorized as another, second, actualization of a capacity that was first actualized, indeed acquired, in some other act—e.g., in perception. Thus, in judging, on the basis of my perception of the spider, that there’s a brown recluse on the wall, I simultaneously acquire and actualize the power to judge that there’s a brown recluse on the wall. In other words, in so judging, I acquire (and simultaneously actualize) the belief that there’s a brown recluse on the wall. I can then actualize that same capacity—that same belief—in another act, for example in the act of inferring that I’m in danger (because there’s a brown recluse on the wall, and the brown recluse is poisonous). Here, my judgment that there’s a brown recluse on the wall appears as an active component of the epistemic act of inferring that I’m in danger, where the new passive component is, of course, the judgment that I’m danger. Beliefs can also be actualized in various other ways, for example when I remember that the brown recluse is poisonous (which I might do without inferring anything from it, or “using” it in any other way). Theorizing these ways in which belief can be actualized is among the remaining tasks of the theory of belief—though they really belong, in a certain sense, to the theory of judgment, since what we’re looking for are acts (epistemic and otherwise) that involve judgments, these being the acts in which belief can be actualized.

The result, then, is this. If we define judgment in terms of epistemic acts, and we define belief as the power to judge, then we will have provided a theory of belief that can both (i) explain the truth of the Ignorance Principle and (ii) respect the fact that belief has some of its causal-explanatory powers essentially. The Ignorance Principle is true simply because belief is a power, and powers can go unactualized. And belief has some of its causal-explanatory powers essentially because it is the power to judge—which means that believing that p necessarily disposes you to judge that p—and because judgment is essentially the kind of thing that can occur as the passive component of an epistemic act. In particular, given that perception is, on one description, the act of judging something on the basis of your perception of the object of that judgment, it follows, from the definition of belief, that you can believe something on the basis of your perception of the object of that belief. It’s thus essential to belief that explanations of the form $\langle S$ believes that p because she saw that $p\rangle$, understood in the natural way (on which the explanation purports to explain the belief by revealing the rationality of holding it) are, if true, good explanations of S’s belief that p. Parallel points hold, of course, for every other kind of epistemic act. And so, again, it follows that each belief has some of its causal-explanatory powers essentially: at the very least, it is essentially the kind of thing that can be explained by the active components of an epistemic act—including, of course, a judgment, i.e., the actualization of another belief.