The Value of Modal Knowledge

 

 

As reflective rational beings, we tend to assume that knowledge of necessity has a special kind of value. Think back to when you first discovered that necessarily 2 + 2 = 4: didn’t you experience this discovery as a kind of revelation—as deep, interesting, and even thrilling? Not only does 2 added to 2 give 4 as a matter of fact, but this could not be otherwise—at any other time, for any other kind of thinking being, in any possible world. It may be useful and informative to discover that there happens to be a cat in the room next door, but it is a discovery of another magnitude that mathematical truths are necessary truths. Modal knowledge strikes us as uniquely valuable and profound—more so than non-modal knowledge of what is actually the case (even mathematically). In philosophy we seek it with particular ardor. But why is that? Why do we find knowledge of necessity so deep and exciting?

            One possible answer is that necessary truths are general or universals truths, while contingent truths are particular truths. Thus if a truth is necessary it is true in all possible worlds, while if a truth is merely contingent it is true only in some possible worlds. And universal statements are just logically stronger than existential statements—they entail more. It is more valuable to know a necessary truth because it has more general scope—intuitively, it says more. However, we don’t generally accord universal statements special value compared to singular or existential statements—as in “All the coins in my pocket are silver” versus “Some of the coins in my pocket are silver”. Nor do we reserve special esteem for knowledge of what is true at all places or for all times—unless this reflects a necessary truth. It is not universality as such that has value but universality over logical space, i.e. necessity.  The truth of a universal quantification is not itself a reason to prize modal knowledge to the degree that we do.

            A quite different suggestion invokes our faculty of knowledge: it is not the modal proposition in itself that is valuable but the faculty by which we know it. We are special not the necessary truth itself. For it is not given to every knower to know necessary truths: you have to be a special kind of being to know such truths. Animals, we may surmise, do not have knowledge of necessary truths, even if they have other kinds of knowledge. Nor do human children have such knowledge until they reach the requisite stage of intellectual maturity. As animals and children may be said to experience lower pleasures not higher pleasures, so they may be said to possess lower but not higher knowledge. They lack Reason or Insight or Intuition or Understanding. Thus modal knowledge is a proof of our unique elevation as knowing beings. However, flattering though this theory may be, it fails to identify the source of value we seek. Let’s accept that we are epistemologically special in virtue of possessing modal knowledge: why does that show that modal knowledge itself is especially valuable? We need to know what it is about the object of such knowledge—what it is that is known—that deserves special esteem. No doubt we are also special for having perceptual knowledge, given that this depends on a highly evolved and sophisticated cognitive system, but we don’t think that perceptual truths themselves (e.g. “It’s raining now”) are especially valuable objects of knowledge. Nor do we accord non-modal knowledge of arithmetic the same status as knowledge of the necessity of arithmetical truths, even though both are beyond the reach of animals and infants. There is something about necessity itself that strikes us as especially worth knowing—as epistemic gold. It is the fact not the faculty that invites admiration.

            I think the right answer has an Aristotelian complexion. Knowledge of necessity is knowledge of essence quaessence. It is knowledge of what makes a thing the thing that it is—its nature and definition. This is to be contrasted with knowledge of contingency, which concerns what merely happens to be the case, with what is true by chance. What is contingently true of an object does not penetrate to its inner being, but only to its accidental characteristics. For example, it is only contingently true that I am wearing spectacles—in no way does that define my identity—but the fact that I have a particular brain is integral to being the person I am. Thus when we know a necessary truth we are at the heart of a thing’s being, not merely hovering at its ontological periphery. So knowledge of necessary truths confers knowledge of a thing’s essential nature—its what-it-is-to-be, as Aristotle would put it. This is deeper knowledge than knowledge of the chance properties of an object, those it could easily have lacked. Chance, accident, and contingency—these are the marks of everything that is external to the core being of a thing. We value modal knowledge, then, because we value knowledge of a thing’s intrinsic essential nature. Modal knowledge is ontologically penetrating.

            This way of thinking posits two ontological levels to reality–a deep level and a superficial level. At the superficial level, we have the contingent and accidental—that which just happens to be true of a thing but could easily have been otherwise. At the deep level, we have essences and natures—that which could not be otherwise. The fact that we value modal knowledge as we do shows that we recognize the existence of these two levels; in particular, that we accept the existence of a level of reality that goes beyond what merely happens to be. It is a level of permanence, fixity, and immutability. This Platonic-sounding level contrasts with the transitory and ever-changing level, that which may be wiped away and abolished. It is the contrast between chance and necessity. Knowledge of the deeper level of reality strikes us as more valuable than knowledge of the more superficial level. It is harder to obtain such knowledge, and when we obtain it we have a more penetrating insight into reality. Any fool can see at a glance that 2 eggs plus 2 eggs equals 4 eggs, but it takes insight to grasp that it is in the very nature of the number 2 that when added to itself it must equal 4. We could reasonably paraphrase “Necessarily 2 + 2 = 4” as “It is in the very nature of the number 2 that doubling it equals 4”. To know this truth we need to have insight into the essential nature of numbers. We are dealing with a metaphysical truth not just an arithmetical truth. We value modal knowledge because we value metaphysical knowledge, which the concept of necessity enables us to possess.

            By way of confirmation of this suggestion notice what happens if we set out to deflate modal knowledge. Suppose we insist that all necessity is just a reflection of conventional linguistic rules, with no bearing on extra-linguistic reality. Then modal knowledge will boil down to knowledge of linguistic conventions and intentions to stick by them. In that case, any special value thought to reside in modal knowledge evaporates, along with the notion of de re necessity. Such a deflationary position is calculated to be revisionist, and is felt to be so. We feel that something valuable has been taken away from us—the idea of reality as composed of things with substantial objective essences, which we might discover. It is the same with nomological necessity: here too the notions of law and causation suffer ontological demotion and epistemological deflation if we decide to restrict ourselves to non-modal concepts (“constant conjunction” and the like). The case is comparable to anti-realist views in ethics and aesthetics. The way we spontaneously understand these domains has been attacked, and we are left with a mere husk of the original article. The disappointment we feel is an indication of our initial valuation: we thought we were dealing with something deep and important, but we have been brought to see that there is much less to it than meets the eye. That is: our intuitive sense of the importance of modality rests open a robustly metaphysical conception of its place in the world. We normally take it that necessity is written deep into the nature of things, and hence deserves our attention and respect; but we may be persuaded (wrongly, I would say) that necessity is nothing but revocable human convention. Our habitual starry-eyed and awestruck estimation of modality has been punctured. Thus we value modal knowledge because we believe (rightly) that it reveals deeps truths about the world. It couples with metaphysical knowledge.

            The question of the value of modal knowledge has an immediate relevance to the value of philosophy. For it is a traditional and powerful view that philosophy is precisely concerned with the discovery of essences quaessences. Suppose that view to be true: then philosophical knowledge is characteristically modal knowledge—knowledge that something is necessarily the case. Accordingly, philosophical knowledge has the value attaching to modal knowledge, which puts philosophy in a special place epistemologically. Not to put too fine a point on it, it makes philosophical knowledge superior (in one respect anyway) to scientific knowledge or historical knowledge or any knowledge that is of non-modal propositions. Philosophy provides knowledge of essence qua essence, while other branches of inquiry provide only knowledge of what is in fact the case—knowledge of the actual world not knowledge of all possible worlds. For many of us, that is why we went into philosophy to begin with—because it offers a uniquely deep insight into reality, extending across all of logical space. It tells us how things must be, not merely how things happen to be.

 

Co

 

Is the Mind Identical to the Brain?

 

 

The mind-body problem is usually formulated as a problem about the relationship between mental and physical events, or about mental and physical attributes, or about “mental phenomena” and the brain. Seldom, if ever, is it formulated as a problem about what we call “the mind”, viewed as an entity bearing mental attributes. That is, we do not debate whether the substance denoted by “the mind” is identical to the substance denoted by “the brain”, to use traditional terminology. In other words, is the thing or object we call “the mind” identical to the thing or objectwe call “the brain”? If we view the mind as an organ, analogous to the heart or stomach, then the question would be whether the mental organ is identical to the brain organ. We would then be able to consider the doctrine of “organ identity”, just as we talk about type and token identity, or property identity. The organ identity thesis is thus the thesis that the organ that is the mind is identical to the organ that is the brain.

            It is important to see that the organ identity thesis does not entail either the type identity or token identity thesis. The mind could be identical to the brain and yet mental events are not identical to brain events: there are two kinds of events, ontologically separate, but they occur in a single substance, called both “the mind” and “the brain”. A single thing can host a variety of events—as the body contains both digestive and respiratory events—without those events being themselves identical. So the falsity of type and token identity theories would not entail the falsity of the organ identity thesis. If we think that standard identity theories are false, this holds out the hope that at least one form of materialism might be true—that the mind is just the brain. We then don’t have to accept a Cartesian dualism of substances or things, but can affirm that there is a single substance that has both mental and physical attributes. That substance can be described either as “the mind” or “the brain”.

            Why don’t philosophers debate this question more? I suspect it is because they think the mind is not a thing: they think that the definite description “the mind” does not denote an object of any kind, still less a physical object like the brain. Rather, when we talk of “the mind” we are really just talking about mental phenomena, so that the phrase “the mind” just means “all mental phenomena”. Then there is nothing left over to consider once we have considered mental events and mental properties—there is no “mental substance” whose relation to the brain we have not investigated. The brain is an individual substance, and maybe also the person, but there is no further individual substance called “the mind”. A person does not have a mind in the way he or she has a brain: the mind is precisely not like an organ of the body. Thus a philosopher might declare, “The mind is not an object!” It is some kind of category mistake to think that the mind is an object; and so there is no room for an identity theory of the object that is the mind.

            But surely this “no-object” view is mistaken. Maybe the mind is not a perceptible object or a spatial object or an object with mass, but that doesn’t imply that it is no kind of object. We certainly talk about the mind as if it is an object: the word “mind” is a count noun, allowing both the plural form and numerical quantifiers, and we have many singular terms purporting to refer to minds. Thus: “A mind is a terrible thing to waste”, “Great minds think alike”, “I have three first-class minds in my metaphysics class”, “Edith’s mind is like no other”, “He is out of his mind”, “My mind is totally exhausted”, “My mind is not identical to yours”, “I am in two minds about it”, and so on. These object-invoking locutions do not refer to bodies or to persons: they objectify the mind itself. As far as ordinary language is concerned, the mind is a thing—a substance, to use old-fashioned term. We need to be given a reason why our ordinary locutions are misleading–and I know of none. The question can then intelligibly arise as to whether this thing is or is not identical to the brain. We need not mean the whole brain: some parts of the brain have no mental correlate (that we know of), so we can exclude these parts from the thesis of identity. The claim will then be that the mind is identical to a part of the brain, say the cerebral cortex. Are there reasons to accept this claim, and are there reasons to doubt it?

            The reasons to accept it are familiar: we avoid Cartesian substance dualism, we respect Ockham’s razor, and we find a natural substance that can be the host and ground of mental events. We have empirically discovered that the brain is the thing referred by “the mind”—it is not the heart or some otherworldly non-spatial entity. If the mind is indeed a thing, then the brain is the thing that it most likely is. But are there any good objections to such a thesis? Objections to type and token identity theories will not entail objections to the organ identity thesis, but perhaps analogous objections will arise for that thesis. So it might be said that the brain could exist without the mind and that the mind could exist without the brain: we can imagine the two things apart in some possible world. That is, there can be zombie brains and disembodied minds: my brain might exist just as it is now but my mind does not exist, and my mind could exist without my brain existing. Note that the zombie claim is not that my brain could exist and host no mental events; it is that my brain could exist and my mind not exist (that specific thing), whether or not my mind itself instantiates any mental properties.

I think neither of these dualistic claims is credible: the existence of my brain just as it is now is sufficient for the existence of my mind (supervenience holds), and it is really not possible for the thing I call my mind to exist in the complete absence of my brain. Any intuitions we may have to the contrary can be easily explained away, so that we are free to accept the identity thesis of mind and brain (while possibly rejecting identity theses for mental events and properties). It is no more possible for the organ that is my mind to exist without my brain than it is possible for the organ that pumps my blood to exist without my heart existing.

A plausible assumption is that “mind” is synonymous with “organ that is responsible for thinking (etc)”, as “heart” is synonymous with “organ that pumps the blood”—at any rate, we can certainly imagine that the terms were introduced in that way. Then it has been empirically discovered that the mental organ is the brain, as it has been discovered that the blood-circulating organ is the heart. We might confuse epistemic possibilities with metaphysical possibilities in both cases—it might have turned out that minds and blood-circulators are different organs of the body (perhaps hearts and brains, respectively)—but once we know what the organs actually are we can claim necessary identity. My mind just is my brain and could not be anything else, as my blood-circulator just is my heart and could not be anything else. Some other mind need not be identical to a brain like mine (say, a Martian mind with a different type of “brain”), but my mind—this particular mind—is identical to that brain. It could not be otherwise.

            Are there difficulties stemming from Leibniz’s law? Well, there are certainly some interesting consequences: we can infer that the mind has a certain size, shape, and weight, since the brain does; and we can infer that the brain thinks and feels, since the mind does. Whatever is true of the brain is true of the mind and vice versa. But we can just accept these entailments as interesting consequences of an empirical discovery, rather like accepting that heat involves particles in motion or that the stomach contains acid—surprising, perhaps, but not refutations of the theory. It has turned out that the organ that thinks (the mind) has various physical characteristics, and that the organ in the head (the brain) has various mental characteristics: surprising, perhaps, but not reasons to reject the identification. A more challenging consequence is as follows: mental events occur in the mind; the mind is identical to the brain; therefore mental events occur in the brain. Similarly: neural events occur in the brain; the mind is identical to the brain; therefore neural events occur in the mind. Here we should remember that identity is symmetrical: if the mind is the brain, then the brain (or a part of it) is the mind—so whatever is true of the brain will be true of the mind. The mind therefore has biochemistry, runs on electricity, divides into two halves, is damp to the touch, and is nutritious when eaten. But again, these can be seen as interesting results, not reasons to reject the identity: surely both things (mind and brain) are likely to have hidden natures that science might disclose, which may not be anticipated by common sense. And then there is the point that it is a good thing if we find what substance mental events occur in, since we want them to occur in something natural and investigable: if they occur in the brain, then they do not occur in some supernatural entity, or in nothing. The identity of the organs doesn’t imply that mental events are neural events or have any of the properties of physical entities (like spatiality), since we are not assuming event identity; it tells us merely that the substance in which mental events occur is a physical substance with certain physiological properties. There is nothing even faintly reductionist about the organ identity theory with respect to mental phenomena.

            A thing (or substance) can easily instantiate different kinds of properties, so there is no logical difficulty about the brain being both a bearer of physical properties and a bearer of mental properties. It is much more difficult to make sense of a single event instantiating both mental and physical properties. According to the organ identity thesis, while the mind is the brain, mental events are not claimed to be physical events—indeed, token identity might be rejected as incoherent. Still less is there any commitment to type or property identity theory. In a sense, then, organ identity is a very weak form of materialism; but it is not trivial, because it excludes substance dualism and has some surprising consequences. It turns out that my mind is in my head, for instance, and that my mind has a specific weight. But that doesn’t mean that mental states are in the head or have weight. The book is on the shelf and has a certain weight, but that doesn’t mean that the story in it is on the shelf or weighs anything. Similarly, my brain turns out to be a thinking thing, given its identity to the mind, and it is conscious; but there is no need to assume that its other properties are likewise mental. If I have a conscious mind and an unconscious mind, then I have a conscious brain and an unconscious brain—I have two brains, as I have two minds (or a single mind with two parts). If someone has a brilliant mind, she has a brilliant brain; and likewise for mature minds, impoverished minds, petty minds, narrow minds, etc. But these propositions all look like natural consequences of an empirical discovery, not conceptual impossibilities. They simply result from the identity claim plus Leibniz’s law.  [1]

            The organ identity theory thus tells us that a single thing can be both mental and physical—so it is a kind of “double aspect” theory. It stands more chance of being true than the standard forms of identity theory, given the compelling objections that have been raised, and yet it is not trivial. It is not in any way a solution to the problem of consciousness, nor a theory of mental states more generally. It simply says that the mind is identical to the brain, i.e. that these two entities are one and the same. The mind, then, is identical to a part of the body. This may not be as much materialism as we would like, but at least it avoids one kind of dualism.

 

Colin McGinn

  [1] It is possible to weaken the theory in order to avoid the consequences of Leibniz’s law, by replacing identity with constitution. Then we don’t have to attribute every property of the mind to the brain and vice versa. But I like the boldness of the straight identity theory.

                                                Consciousness and Language

 

 

If the mind is computational, then there must be a language of thought. This is because computations are operations defined over symbols: thought processes must be symbolic processes.   The original conception of a Turing machine makes this very clear, since the operation of writing and erasing marks on a tape is obviously a process defined over symbols (ones and zeros, or numerals thereof). But the generalized notion of a computation, which involves any procedure of symbolic manipulation, will also entail that there is a language of thought, granted that thought processes are (or involve) computational processes. Thoughts will consist of, or be encoded in, sequences of word-like elements upon which operations are performed by something like a computer program. We have good reasons to believe that the mind is computational (which I won’t rehearse), so we have good reasons to believe in a language of thought. Moreover, the hypothesis of a language of thought helps deal with various conceptual and empirical problems.

            And yet there is a marked reluctance to accept it. Why? I think the main reason for this reluctance is that we do not perceive the language of thought (call it LT). We do not see or hear the words that compose it; neither do we introspect these words. By contrast, we do see and hear (and sometimes introspect) the words of our ordinary public language (call this LC for “language of communication”).    [1] That is, we are conscious of LC but we are notconscious of LT. I am now looking at words of my LC as I write, but as I think I am not in any analogous cognitive relation to the words of my LT. The language of thought is an unconscious language—not repressed, to be sure, but deeply hidden, inaccessible to consciousness. Why LT should be hidden is an interesting question, with no obvious answer, but it evidently is (granted its existence). It exists in the mind, entering into mental computations, but it does not exist in consciousness. It affects the conscious mind, leading us to form conscious thoughts we couldn’t have without it, but it never reveals itself to consciousness—it hovers in the background, invisibly and inaudibly. Thus we have no direct knowledge of its existence; its existence is inferred. We do not believe in a language of thought because of the manifest contents of consciousness, as we believe in thoughts, emotions, and sensations; we believe in it in the way we believe in atoms or genes. In fact, no one has ever caught a glimpse of LT and it remains elusive—we don’t even know what its lexicon looks like. It must contain symbols with an arbitrary connection to what they denote and with their own internal composition, but we don’t know what these symbols are—we don’t know the alphabet out of which the lexicon of LT is constructed. This epistemological situation is surely a large part of the reason that people doubt that a language of thought exists—no one has ever seen or heard the words that compose it. By contrast, we have no trouble accepting that LC exists, because we have all seen the words of LC: we are conscious of the words of LC in multiple ways—by seeing them written down, hearing them spoken, producing them in speech, and introspecting them in inner speech. It is not that we have merely theoretical reasons to believe in LC; we have direct evidence that LC exists. Because of this epistemic asymmetry we are apt to be skeptical of LTand accepting of LC.

            Now it is not that this asymmetry constitutes a good reason to believe in LC but not in LT, on pain of doubting every theoretical entity we have ever had reason to posit; and there is ample precedent for the notion of unconscious mental realities. But as a matter of human psychology people have a tendency to believe in what they can sense and to doubt what they cannot. To be conscious of something is always the strongest reason for believing in it. The point I want to make is that the epistemic asymmetry is entirely contingent and should not be interpreted as having ontological significance; it is merely epistemological. I aim to loosen the hold of the conviction that LT is suspect while LC is pucker. I shall do this by inverting the epistemology of the two languages: in a conceivable case we could be conscious of the language of thought but not conscious of the language of communication. And just as in such a case we should not interpret the epistemic asymmetry as having ontological significance, so we should not do so as things actually are with us. It merely happens that we have direct evidence of LC and not of LT; there is nothing metaphysically deep here. It might have been otherwise. It is not of the essence of LT to be unconscious and of the essence of LC to be conscious; the epistemic asymmetry is not built into their very nature.

Consider then the following imaginary case. First we suppose that LT is conscious for certain possible thinkers; for concreteness suppose that LT is Latin (once the language of learned European thought). Whenever these possible thinkers think, sentences of Latin surge conspicuously through their consciousness, encoding their thoughts. They have inherited this language from their ancestors and it is built into their genes (don’t ask me how). Mental computations are performed on Latin strings and the resulting thoughts contain words of Latin. Maybe these strings enter consciousness in some sensory mode—auditory images perhaps, or possibly visual. Just as we can introspect our conscious inner speech in our acquired language, so they can introspect their innate language of thought. This seems perfectly possible. It will then not be a difficult task to persuade them that they have a language of thought: that is evident from their everyday consciousness and everyone agrees about what this language is like. It is quite evident to them that they think in Latin; they have direct knowledge of this fact. There are no debates about whether such a language exists or what composes it; it is as clear as conscious thought itself. They can in good conscience avail themselves of the theoretical benefits of positing an LT—except that they don’t posit it, since they are acquainted with it. It might be that their spoken language is derived from their internal language—they speak Latin because they think Latin. They have molded their LC around their LT, quite deliberately; or perhaps evolution has taken a short cut to producing a communicative language by simply co-opting the language already coded in their genes. Given their epistemic relation to their language of thought, there will not be much controversy about invoking it in theoretical contexts.

            But what about LC and consciousness—how could its existence be a matter of conjecture, inference, and speculative positing? Aren’t our possible people bound to know it directly? Perhaps surprisingly, the answer is no. LC could be inaccessible to consciousness, just as LT is for us. For consider speakers with a kind of linguistic blindsight: when sentences are uttered in their presence they have no conscious impression of sound—it is as if they are deaf—but still the auditory input is processed by the brain, producing a belief about what was communicated. They know that the speaker said that p by producing certain sounds, but they have no consciousness of those sounds—they are processed unconsciously. Thus they have no consciousness of the words that compose their LC: all the work of hearing, parsing, and comprehension is done behind the scenes, with only the output reaching conscious awareness. We can suppose that no one has ever had a conscious percept of the words of their LC, their sound or shape, while they have all had conscious awareness of their LT. What they have in respect of LC is deafhearing: they hear (process) the words unconsciously, but they are deaf to them consciously. What they hear in this mode is inaccessible to consciousness. It is just like regular blindsight with respect to written words: someone might direct their eyes at written language and have no conscious impression of what is before them, yet the visual system might be able to process the stimuli in such a way as to produce knowledge of the inscription in question. They might engage in “blind-reading” through their eyes. Such a person could not tell you what the words they see (process) look like, since they are never conscious of these words, but the words exist and the person responds to them. Similarly, they might be able to produce spoken strings and yet not be conscious of their actions: it is all done behind the scenes with no awareness of what sounds are being produced. We are not normally conscious of the fine structure of our actions and many animals presumably lack consciousness of their motor activity (consider insects); well, these speakers lack any conscious knowledge of their speech acts—though they perform them perfectly adequately. In sum, they are not acquainted with their LC: it exists and they use it, but they are not conscious of its intrinsic character—its alphabet, phonetic properties, intonation patterns, etc. It is, as far as they are concerned, an unconscious language. We might compare it to the communication system used by bees: I don’t know whether bees are conscious (I rather think they are) but we can suppose that they are not, and then their language is an unconscious language—no bee is conscious of the words that compose its language. That doesn’t prevent bee language from existing. Bees just happen not have any conscious awareness of the language they employ. There is no necessity for a public language of communication to be conscious.    [2]

            Given this description of my hypothetical language users, what is their theoretical position vis-à-vis LT and LC? They invert our ontological prejudices. They have no scruples about believing in a language of thought, but they have their doubts about a language of communication. They may allow that an LC must exist, given that they communicate and understand each other, but the lack of direct evidence troubles them, and some may be openly skeptical. Some may make a living out of denying that there is a language of communication at all. After all, no one has ever directly observed LC, and the idea of an unconscious language strikes some as inherently problematic. They have no trouble with LT, however, since it is so evident to consciousness—as certain as thought itself (“I think in Latin” is indubitable for them). They don’t feel the need to prove the existence of LT, but they do think that the hypothesis of LC cries out for some sort of defense—perhaps arguing that it is entailed by a computational view of communication. But we can see from the outside that they are overly impressed by their own epistemological biases, reading far too much into them. We know that their LC exists, even if they doubt it. Just because they are not consciously aware of the words of LC doesn’t mean that there are none or that there is anything metaphorical or suspect about the notion of a language of communication. This is just a contingent fact about their epistemic powers. Similarly, it is just a contingent fact about our epistemic powers that we are conscious of our public language but not of our private language. There is a hidden language of thought—there has to be if the mind is computational—but we don’t happen to be conscious of it. Maybe we are indirectly conscious of it, because we are conscious of the work it does, but we are not conscious of it in its entirety. In the same way, my inverted speakers may have glimmerings of the public language they use because of their awareness of its effects in their consciousness, but they are (by hypothesis) not aware of the full nature of LC. We would think them irrational, or excessively cautious, if they were seriously to doubt the existence of a language of communication; but then why are we being commendably skeptical about the existence of a language of thought? If we have solid arguments that there must be an LT, why should its inaccessibility to consciousness count against its existence? Why should a language we use necessarily be a language of which we are conscious? Perhaps there are good biological reasons that we are not conscious of our LT  (it would clutter up our attention or be too costly metabolically), but these are not reasons to doubt its existence. After all, we are not conscious of a lot of what goes in with our ordinary spoken language too. In the case of bees it may well be that their communicative language has an internal counterpart that helps them navigate the world—a language of bee thought—and it too will be an unconscious language. Bees may have both an LC and an LT with neither of them conscious, simply because bees are not conscious–or whatever smidgen of consciousness they possess is not directed at their linguistic skills.

            I end with this thought: perhaps the reason we are not conscious of the language of thought is that it is just too abstract to enter our consciousness. The symbols in LT are universal to the human species, so they are less specific than the symbols of a spoken language (or a sign language). They are components of an abstract computational structure. Just as we cannot have in mind an image of a triangle in general, but only specific types of triangle, so we cannot have in mind a word belonging to an abstract universal language, but only words belonging to a particularized language. Consciousness will not admit elements of the requisite generality and abstractness: for how could such elements be contents of consciousness? We can have concepts of abstract things, but it is harder to see how the conscious linguistic medium of concepts could itself be abstract. Consciousness filters out the abstract, admitting only the concrete, while the unconscious tolerates the abstract. Why this should be I don’t know, but it seems like a possibility. Certainly it is a good question why the language of thought should be so removed from our consciousness.

 

    [1] I say this for the sake of argument; actually it is not clear that we do perceive our language of communication. We perceive various sounds and marks with the senses, but it is another question whether we perceive words and sentences. These are more abstract categories than sounds and marks, more deeply psychological; and it may be that we bring these categories to external stimuli rather than perceiving them there. Indeed, it may be that we never really perceive (with the senses) words and sentences—we infer them from what we do so perceive (or impose them). So the language of communication may not as accessible to consciousness as we think.

    [2] We need not suppose that bees engage in acts of speaker meaning, as characterized by Grice, which does require consciousness; it suffices for the point that they employ a system of communication whose nature is not given to them.