What is Belief?
For all the work that has been done on the topic of belief, do we really know what belief is? What kind of state (if state it be) is the belief state? Two suggestions have been prominent: belief is a feeling and belief is a disposition. Either belief is a state of consciousness analogous to sensation (pain, seeing red, feeling sad) or it is a tendency to behave in a certain way (assenting to a proposition, combining with desire to produce action). The OED defines “believe” as “feel sure that (something) is true”, thus categorizing belief as a type of feeling: not “be sure” but “feelsure”. What that feeling might be is left undetermined, though the definition has the ring of truth. And indeed belief is connected to feeling: your feelings tend to change when you acquire a belief, and there is such a thing as feeling sure. But what about beliefs you hold without thinking about them– are those beliefs all associated with feelings? Do you feel sure that London is in England, for example, even when the thought has not crossed your mind in months? Here is where the dispositional theory suggests itself: belief isn’t an episodic state of consciousness but a readiness to act in a certain way—to respond “yes” when asked whether London is in England, say. Ramsey said belief is a “map by which we steer”, emphasizing that beliefs guide action (but do we inspect our beliefs as we inspect maps?). And certainly beliefs and dispositions are tightly connected (as are desires and dispositions): your dispositions change when you acquire a belief, and belief encourages assent behavior. But is this what a belief is? Isn’t it rather the mental state that gives rise to the disposition? What if you had a tendency to assent verbally to propositions not because you believe them but because you have been rigged up that way by a clever scientist intent on simulating the state of belief? In general, dispositional theories confound properties (states, facts) with their causal consequences; and we want to know what belief is not what it does. The OED also has this under “believe”: “accept the statement (of someone) as true”. But don’t we accept statements because of what we believe? It isn’t that the belief is the acceptance. It is hard to avoid the impression that the dictionary (and the usual philosophical theories) conflates the symptoms of belief—feelings and dispositions–with belief itself. But then what is belief itself exactly?
Are we acquainted with belief itself? We are acquainted with sensations and behavior, both signs of belief, but are we acquainted with beliefs? The answer is not obvious. If we are, it seems curious that we draw a blank when considering the nature of belief; but if we are not, why do we bandy the concept around with such confidence? Is it perhaps that the concept is logically primitive and hence admits of no explanation in other terms? But that can’t be the reason for our ignorance, because the same is true of many concepts and yet we are not blind to the nature of their reference (pain, seeing red, maybe moral goodness). Or is it that the felt ignorance is an illusion born of a mistaken assumption, namely that we only know what a mental phenomenon is if we can reduce it either to a feeling or to a disposition? Maybe we know exactly what belief is but we think we don’t because beliefs are not sensational or behavioral, these being our preferred touchstones of mental reality when thinking philosophically. But that approach, though not unsound in principle, is hard to square with an evident fact: we really don’t know what it is to believe something—we have no conception of what fact is at issue. Once belief is distinguished from its symptoms its elusiveness becomes evident (compare Hume on causation).
This leaves us with another possibility—that “believes” is really a name for an I-know-not-what that we introduce to denote something that we reasonably believe to exist but can’t properly conceptualize. Belief is thus that state, whatever it is, that has such and such symptoms and plays such and such a role but whose nature we find elusive. In short, “belief” is a theoretical term—not just in application to others but also in application to oneself. Our knowledge of belief operates at one remove from the thing itself, which is why we have such an indeterminate conception of it. A similar approach might be suggested for the concepts of meaning and the self: these too are not directly encountered constituents of consciousness, which is why we can’t reconstruct them in such terms, but they are real nonetheless, just at some epistemic distance from our cognitive faculties. That is, not all parts of what we think of as the mind exist at the same epistemic level (and not because of a detached Freudian unconscious); some are not objects of direct inspection (perceptual or introspective). The ontology of folk psychology is an amalgam of these two types of fact (and we can add desire to belief): the mind consists of directly known constituents and relatively unknown constituents. Differently stated, belief (desire, meaning, the self) is a state that we refer to but are not acquainted with; we know many of its properties, but not its intrinsic nature. We know it is a propositional attitude (but what is an attitude exactly?) and that it involves the exercise of concepts, as well as being a truth-bearer, subject to referential opacity, and capable of combining with desire to lead to action: but we don’t grasp what kind of state it is—not in its intrinsic nature. The state gives rise to inner feelings and to outer behavior, but we have no clear idea of what it is in itself. We experience shadows of it, fleeting intimations and glimpses, but we have no firm conception of the thing itself: it is just “that which gives rise to these symptoms”. Ask yourself what kind of mental state you are in when you are asleep: you have various beliefs, but what is their mode of existence exactly? You might be tempted to reach for the concept of a disposition, but we have been down that road before—what is the ground of such a disposition? Let’s face it: you don’t know what to say, and yet you don’t doubt that you are in some sort of mental state. You might sputter that you are in a “cognitive state”, but that raises the same question over again: what kind of state is that? Not a feeling state and not a disposition, but a sui generis state that confounds comprehension. As we might say, we have only a partial grasp of what belief is. And the part we don’t grasp intrigues us the most, i.e. the very being of belief.
I grant that this position might sound counterintuitive. Doesn’t the Cogito express certain knowledge (“I believe, therefore I am”)? But how can that be if we don’t know what thinking (believing) is? However, this is really not such a paradoxical position to be in: we know that we think and believe, and that this entails our existence, but it doesn’t follow that we know what thinking and believing are—or what the self is for that matter. And did Descartes ever claim anything to the contrary—did he suppose that the nature of thinking is totally transparent to us? Knowing that something exists is not the same as knowing its nature. If Descartes had claimed that thinking is processing sentences in the language of thought, he could have been wrong about that; but this wouldn’t undermine the Cogito. In fact, I would say that if you focus really hard on what is going on when you believe something you will see that nothing determinate comes into view—you never catch your belief in flagrante, as it were. And you have no clear conception of what it is that you attribute when you ascribe beliefs to others (beyond their conceptual content). Nor does knowledge of the brain help: identifying belief with neural excitation in the B-fibers, say, affords no knowledge of what belief is in the ordinary sense. The problem is that neither does anything else—crucially, not introspection. We didn’t come by the concept of belief by noticing feelings of belief in ourselves (where would those feelings to be located?), or by observing the operation of dispositions to behavior; rather, we introduced a term for a type of psychological state whose nature was not evident to us but which we were sure existed. I have evidence for my beliefs drawn from my experience (e.g. feelings of conviction), but I don’t believe in beliefs because I can grasp them whole. I see them through a glass darkly. I have a nebulous sense that certain propositions attract my assent, as if gravitationally, but what exactly my mind is up to I cannot tell. Even the strongest of our beliefs, say religious or moral or scientific beliefs, fail to disclose their inner nature—we just find ourselves filled with passionate conviction about certain things. It isn’t like feeling a headache or a hunger pang in the stomach. Nor is it like hearing a sentence in your head. It isn’t like anything.
Psychology used to be conceived as an introspective science, and then later as a science of observable behavior, but these ideas were predicated on a certain conception of the essence of the mind. Either the mind consists of inner episodes of consciousness of which we have immediate introspective awareness, or it consists of outer behavior that can be perceived externally. But the case of belief (also desire) shows that these alternatives are not exhaustive and are fundamentally on the wrong track. In so far as psychology is about belief and kindred states, it is not about feelings or behavioral dispositions, but about facts we find systematically elusive, which fit into neither category. Beliefs are not feelings and they are not dispositions to behavior, yet there are fully mental phenomena, paradigmatically so. As Hume would say, we have no impression of belief, yet belief is real and knowable (in some of its aspects). Belief is yet another example of the limits of human cognition. Psychology thus has an elusive subject matter.
 The background to this essay is scattered. The issues discussed bubble under the surface of Wittgenstein’s Philosophical Investigations and are explicitly posed in Kripke’s Wittgenstein on Rules and Private Language (as well as my Wittgenstein on Meaning). In addition, the emphasis on ignorance reflects my standing interest in human mysteries as they pertain to philosophy. Hume is hovering paternally in the wings. Russell makes a brief appearance.
 It might be said that belief is a computational state and that this gives its essential nature. There is a lot to be said about this suggestion; suffice it to remark that this doesn’t give us a conception of belief comparable to our intuitive notions of pain or seeing red. Belief may well have computational properties, but it is another thing to claim that this is what belief is (would it follow that computers believe?).