Particles and Identity

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                                                Particles and Identity

 

 

In the case of statues and similar objects we can separate the identity of the thing from its substance. Thus the statue is not identical to the piece of bronze that composes it, because the piece but not the statue survives being melted down. The piece is the aggregate of its constituent particles, but the statue is a particular form of that aggregate. For composite objects in general, the object is not identical to the mass of particles that composes it: the constitution relation does not coincide with the identity relation.

            But what should we say about the particles themselves? Suppose that electrons are physically basic: can their identity come apart from their constitution? Could we melt down an electron so as to destroy the electron but leave its substance intact? That could not consist in rearranging its constituents, because it has none. We cannot destroy the electron and leave the aggregate of its parts intact, since it is not composed of an aggregate. So it is not clear what it would be for its substance to survive the destruction of the electron itself. We can’t remove the form of the electron and leave the elements that compose that form. You might try saying that we could destroy the electron but leave its single constituent intact. But it is that single constituent, so when the electron goes it goes too. Nor can we suppose that the electron is composed of a substance that does not consist of electrons: for what could that substance be? If it were composed of some other type of particle, we could just repeat the argument for that particle.

            For simple objects, then, we cannot produce a statue-type example. The existence of the object and the existence of its substance cannot be pulled apart. At the basic level, constitution is identity. Not everything is composed of something to which it is not identical. So the distinction between identity and constitution is not a deep fact about the universe. It arises only at the level of composite objects.

 

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Appearance Without Reality

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                                                Appearance Without Reality

 

 

Is it possible for everything to be an appearance? Might there be nothing in the world but appearances? Granted, there may be many appearances for which there is no corresponding reality (of the kind that we normally suppose), but could this be universally true? Is the pure-appearance world a possible world? I think not, for two reasons. First, appearances must be appearances to someone: there cannot be appearances that float free of a subject for whom they are appearances. Nor can a subject be an appearance of a subject—for who is that appearance an appearance to? Second, appearances must have causes outside themselves: they cannot be self-causing or entirely uncaused. Not all realities need to have a cause (say, the first cause), but appearances cannot come to exist causelessly. This is because they must be appearances of something, and that something cannot itself be an appearance. The logical form of appearance statements is: “A is an appearance of x to y”. That is the structure of appearance. So every appearance has a non-appearance cause. An appearance may be caused by an external object in the standard way, or it may be caused by the state of a brain existing in a vat, or it may be caused by God’s magic touch: but it has to be caused by something. The epistemological problem of appearance is that we don’t know for certain what the nature of the cause is—hence skepticism. We know that there has to be some cause, but we don’t know what cause. We know that our visual experiences, for example, are caused by something, and we may even have an exhaustive list of all the possible causes, but we cannot definitively select a particular item from the list. The appearances underdetermine their specific cause, but they necessarily have a cause—and that cause must be sufficient to bring about the appearances with their specific character. But appearances are not of such a nature that their cause can be read off them. That’s the trouble with appearances qua appearances. Still, we know that they must have some sort of non-appearance cause; so the world cannot consist solely of appearances. There must be a reality that appears and a reality that appearances appear to—there cannot be appearances alone. It cannot be appearances all the way down.

 

C

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Truth and Existence

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                                                Truth and Existence

 

 

The concepts of truth and existence form a natural pair. They are both highly general abstract concepts. They have both been suspected of being pseudo-properties, expressed by logically misleading predicates. They have both been declared redundant, adding nothing to their bearers: calling a proposition true amounts to no more than affirming the proposition, and ascribing existence to a denoted object does nothing more than bring out what is presupposed in denoting that object. Also, truth pairs with falsehood in the way existence pairs with non-existence: truth and existence are positive attributes, while falsehood and non-existence are types of lack. Truth and existence are deemed good, while falsehood and non-existence are deemed bad: we aim to assert what is true, as we aim to refer to what exists. If we fail in these aims, we do something amiss. Finally, it has often been supposed that truth and existence are fundamental and indefinable concepts, with the associated properties ontologically primitive (and vaguely “queer”). Neither property can be perceived via the senses, and neither plays a causal role in how the world works. They both seem non-empirical, non-natural, and oddly diaphanous.

            This raises the question of whether truth and existence are related in any way: do they perhaps enter into each other’s essential nature? If there is any interesting connection, it will not be simple—not a matter of defining one in terms of the other by substitution. Thus it is hopeless to suggest that ”p is true” means “p exists”, since a proposition can exist without being true (though the former follows from the latter). And it is equally hopeless to equate “a exists” with “a is true”, since objects cannot be true (or false). Clearly truth and existence are not the same property. But the connection might be less direct—one concept might be linked to the other in combination with other concepts. Thus consider: “A proposition is true if and only if it designates an existing state of affairs”. That sounds very much on the right lines (Tarski mentions it as a possible definition of truth). Note that we need to include “existing” here because a proposition might designate a possible state of affairs that does not exist (is not actual): the possible state of affairs of snow being yellow does not exist. The world is the totality of existing states of affairs. Given that we are happy with states of affairs, and with applying the concept of existence to them, this seems like a perfectly worthy definition of truth; and it contains the concept of existence essentially. Thus truth is conceptually linked to existence.

            What about the other way round—is existence linked to truth? The following sounds right: if a exists, then we can make true statements about a. If a does not exist, then we cannot make true statements about a—we can make only false statements or statements that are neither true nor false. Existence is a necessary condition for true predication: we cannot speak truly of something that does not exist. Someone might object that this principle is false for fictional objects, since we can say truly that Sherlock Holmes is a detective. Maybe or maybe not, but we can easily strengthen the principle to say that existence is a necessary condition of literal or factual truth. Thus the concept of existence entails a consequence concerning truth—existence is what makes truth possible. In a world with no existence there is no truth. If we are feeling ambitious, we might even try to define existence this way: an object exists if and only if there are true statements about it. This would be the analogue of defining truth in terms of existing states of affairs. But we do not need to go that far in order to recognize a non-trivial conceptual link—a kind of mutual conceptual dependence. Grasp of the concept of truth involves grasp of the concept of existence and vice versa: one concept feeds into the other.   

            Granted these links, the similarities between truth and existence fall naturally into place: they are concepts that presuppose each other. Truth is all about the existence of states of affairs, and existence is all about the stating of truths. Truth is a certain kind of existence, and existence is the basis of truth. We have the word “true” so that we can describe existing of states of affairs, and we have the word “exists” so that we can describe what makes truth possible. We could get along without these short words, using only the longwinded formulations, saying things like, “Your statement designates an existing state of affairs” and “a meets the condition for allowing true statements about a”. What is notable about these definitions is that each concept incorporates the other concept essentially. Thus truth and existence are natural conceptual partners: they point towards each other.

 

Colin McGinn

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A Refutation of Positivism

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A Refutation of Positivism

 

 

The positivists maintain that a sentence is meaningful if and only if it is verifiable. Thus a sentence can be said to be both meaningless and unverifiable. Here is a possible counterexample to that claim: “It’s raining”. This sentence is not meaningless, but it is not verifiable–and similarly for all other indexical sentences. Considered out of context, just in virtue of their lexical meaning (what Kaplan calls character), such sentences are not verifiable—they are unverifiable. It will be replied that we need to consider such sentences in a context in order for them to be verifiable—we need to consider the proposition they express in a particular context of use (what Kaplan calls content). That is undoubtedly correct, but now we are talking about propositions (or statements or sentences “under an interpretation”), not sentences per se. Thus we might reformulate the positivist’s principle to read: A sentence is meaningful if it expresses a proposition that can be verified, and it is meaningless if it expresses a proposition that can’t be verified. (The same point goes for falsifiability as a criterion of meaningfulness.) This implies that a sentence can be meaningless and yet express an unverifiable proposition. But how can a sentence be meaningless if it expresses a proposition? Either it expresses no proposition, in which case it cannot be either verifiable or unverifiable; or it does express a proposition, in which case it is meaningful. Meaningfulness (or the lack of it) is a property of a sentence; verifiability (or the lack of it) is a property of a proposition. The positivist’s principle conflates this distinction, which is what enables it to sound like a viable principle.

            Some sentences are meaningless in a straightforward way, such as ungrammatical sentences or sentences like “Twas brillig and the slithy toves did gyre and gimble in the wabe”. Into this category falls the positivist’s favorite example of meaningless metaphysics, Heidegger’s “Nothing noths”. The problem here stems not from unverifiability but from other kinds of linguistic defect—and no proposition is accordingly expressed (unless we stipulate a sense for the problematic verb “noths”). Other sentences arguably fail to express verifiable propositions, for example “God exists”; but to call them meaningless appears far-fetched. The only reason “God exists” is unverifiable is that it expresses a proposition that is unverifiable; but then it is meaningful in virtue of expressing that proposition. The problem for the positivist is that no sentences fall between these two possibilities: no sentences are both unverifiable and meaningless—simply because to be unverifiable requires a proposition to have that property. Any sentence that fails to be verifiable because it fails to express a proposition at all will be so for reasons other than its unverifiability, say by being ungrammatical. Such sentences are unverifiable only in the entirely trivial sense that a brick is unverifiable: it is simply not the kind of thing that could be verified. A sentence can be unverifiable in the non-trivial sense only if the question of its verifiability can arise, but that requires an expressed proposition to be a candidate for verifiability. So the sentence must be meaningful after all.  

            Nor can we say that a proposition is meaningful if and only if it is verifiable (or falsifiable), since it is a category mistake to call a proposition meaningful or meaningless. A proposition has meaningfulness built into it (it is a meaning). Sentences are meaningful in virtue of expressing propositions, and these propositions can be verifiable or unverifiable; but they cannot express propositions without thereby being meaningful—and this is what they need in order to be verifiable or not. Indeed, we should not speak of sentences as verifiable at all, unless this is simply short for “expresses a verifiable proposition”–in which case the problem with the positivist’s principle is evident straight off. Expressing an unverifiable proposition is a way of being meaningful, not meaningless. Intuitively, we can only know that a sentence is unverifiable if we know what it says, but if it says something then it must be meaningful. Positivism thus rests on confusion between sentences and propositions–bearers of meaning and bearers of verification.

 

Colin McGinn

 

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The Value of a Life

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The Value of a Life

 

 

 

 

It is natural to think that the value of a life depends on the nature of that life. The value of a life is internal to it. It depends on what happens to the individual, what he or she accomplishes, what he or she is. But this way of thinking depends on an assumption of uniqueness—to the effect that the individual has no duplicate. Suppose instead that you have a precise duplicate living somewhere, an individual who is exactly like you physically and mentally. If you accomplish something, so does your duplicate; there is nothing you can do or feel or think that your duplicate cannot do or feel or think. If you die tomorrow your duplicate will carry on, living a life exactly like yours. What if you have a million such duplicates dotted all over the universe? There is no shortage of people sharing whatever it is that characterizes your life: tokens of your type exist in abundance. When you die no one will be able to say, “They broke the mold with that one!” Whatever you were doing one of your duplicates could step in and do it. There is nothing unique about you, nothing irreplaceable, nothing special—people like you are a dime a dozen. Given suitable arrangements, no one would even notice your absence, not even your spouse.

            But what about your value to yourself: does that also depend on the contingent fact of uniqueness? I fear so: it will be reduced by the existence of duplicates– you will value your life less than you would if you had no duplicates. For you will see that there is nothing uniquely valuable, objectively speaking, about your individual life, however valuable it may be as a type.  [1] You may not want to die considered as an individual, but you have to admit that you are not contributing anything that no one else can contribute. Part of the value of your actual life is what you uniquely are, but if we abolish uniqueness that part is no more. Uniqueness contributes to the value of a person’s life, but uniqueness is not a necessary truth. In some possible worlds you are as common as dirt; in those worlds your life is less valuable than it is in the actual world.

We must conclude, then, that the value of a life depends, partly at least, on facts that lie outside the confines of that life—on who else exists. Compare species: it is worse if a qualitatively unique species goes extinct than it is if a species with a biological duplicate goes extinct. Suppose two distinct species of birds converge on the same phenotype after millions of years of evolution from a remote common ancestor: the intermediate species go through a different evolutionary history, but end up in the same place. We would say that they are distinct species, but they are qualitatively indistinguishable. If one goes extinct, the other remains. Surely this is less bad than a qualitatively unique species going extinct. Uniqueness matters to value. Similarly, the value of a human life depends on what other lives there are; it is not entirely internal to the individual life. The value of your individual life can be undermined by the existence of people just like you. It is less of a tragedy if you die in a world in which there are others similar to you.

 

  [1] The token may have value qua token, but it will not have as much value if it is merely one token of a multiply instantiated type.

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The Value of Modal Knowledge

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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

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Competence and Performance Multiplied

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Competence and Performance Multiplied

 

 

In psycholinguistics it is customary to distinguish competence from performance.  [1] Competence is an internal cognitive structure (“knowledge of grammar”) while performance is the outward expression of this knowledge in actual speech. Performance is conceived as the externalization of competence. But this dualism is too simple: we need to recognize several competence-performance distinctions—at least three that I can think of. This is because there are several kinds of linguistic competence: competence in the language of thought, competence in the language of inner speech, and competence in the language of outer speech (call these T-language, I-language, and O-language, respectively). T-language is the innate language that is coded in the genes in all normal humans (what Chomsky calls Universal Grammar and Fodor calls the Language of Thought): it is the formal computational basis for thought. Here we need to distinguish the internal representation of the language (competence) from its deployment in actual thinking (performance)—the cognitive structure from its expression in thought. We need not suppose that this structure takes the form of knowledge—we are not obliged to maintain that each thinker knowshis or her T-language (its constituents and rules of combination). All we have to accept is that the brain-mind codes the T-language in some way, presumably unconsciously. What is important is that the process or activity of thinking is not identical to this internal structure: it is one manifestation of the structure and is susceptible to various kinds of breakdown that don’t undermine the integrity of the underlying competence (fatigue, drugs, disease, etc). Note that here the performance aspect is purely internal, not a type of external behavior (though we can think of it as inner behavior). A being could in principle exhibit a competence-performance distinction with respect to its T-language and not behave at all (externally).

            Now consider inner speech: this is not the same as thought, though there is doubtless overlap. It is the passing of words through consciousness, and is best understood as a hybrid of one’s native language and one’s T-language. For simplicity, suppose that English speakers use English as their I-language: then again we have a distinction between competence and performance in this language. On the one hand, there is the mastery of the language in question conceived as a cognitive structure (even a straightforward case of knowledge); on the other hand, there is the deployment of this structure in acts of inner speech. Again, this performance is subject to factors that leave the basic competence untouched: the knowledge can remain the same though the actual course of inner speech can vary according to circumstances. One person might have a lot of inner speech and another person relatively little, even though they both are equally competent in the underlying language. It is to be assumed that this competence embeds competence in the T-language: our competence in the language of thought is part of our competence in the language of inner speech. But we can’t identify the two kinds of competence or performance: they involve different layers of psycholinguistic reality. Note too that this second kind of performance is also purely an inner reality: episodes of inner speech are precisely that, not overt behavioral events. It might also be more basic than outer speech (like T-language), preceding it in evolutionary history.

            Finally, we have outer speech: the external expression of the previous two levels of linguistic reality. A speaker has mastery of his or her native language and also has the ability to externalize that mastery in acts of communication. These are separate things that can in principle be dissociated: you could have competence without performance (paralysis) and performance without competence (a well-trained parrot). Various factors can influence performance and leave competence unaffected. Presumably the previous two levels are embedded in this third level: we use our competence in T-language and I-language in our acts of external speech. The performance aspect includes the motor system, so it is different from the previous two levels of performance, which don’t engage any muscles. Each competence-performance division coexists with the others in normal humans, but they are distinct psychological realities: thinking, speaking inwardly, and speaking outwardly. All are exercises of language, but they involve different types of competence and performance, subtly interrelated.

            I stated that the third level involves outer speech, making noises with the mouth in most cases, but actually that is strictly wrong. Here again the performance is essentially mental in nature: this is because a speaker could in principle engage in linguistic articulation and not be engaging in overt behavior. The brain in a vat proves this most dramatically: the motor centers of your brain issue orders to your mouth but your mouth isn’t there. You are performing acts of would-be external speech but nothing is coming out—still you are engaging in linguistic performance. Competence in your native language is connecting with motor instructions to body parts that happen not to exist: it would seem to you just as if you were speaking (we can’t refute skepticism by claiming certainty that we are speaking out loud). There is still a competence-performance distinction, but it does not involve any audible speech. Strictly speaking, bodily performance is not essential to “outer” speech. We can’t be behaviorists about any kind of performance, not to mention competence, since thought, inner speech, and “outer” speech are not bodily in nature. True, a brain in a vat is not performing acts of audible speech, but psychologically such a brain is just like an ordinary embodied speaker. Strictly, then, all performance, like all competence, takes place within the subject, behavior being a dispensable effect. 

            There are three uses of language—in thinking, inner speech, and outer speech—and each admits of a competence-performance distinction.  [2] The situation is therefore more complex than the simple competence-performance distinction has made it seem. There are several types of linguistic competence and several types of linguistic performance, not a single dualism.     

 

  [1] This distinction goes back to Chomsky’s earliest work on language and is central to his rejection of behaviorism. It is analogous to the distinction between the categorical basis of a disposition and its manifestations—say, molecular structure and chemical reactions. In psychology it is a special case of the distinction between knowledge (or mental representation in general) and acting on knowledge—cognition and volition basically. The distinction is hard to contest.

  [2] I leave aside the question of whether there might be other uses of language, say in memory, imagination, or dreaming. Is it possible that dreaming involves linguistic performances different in kind from the three I have identified? Dream talking is certainly not much like conscious inner speech. Wittgenstein spoke of there being different language-games; maybe it would be better to speak of different language-worlds—the world of thought (conscious and unconscious), the world of silent inner monologue, the world of outer perceptible utterance, and the world of somnolent dream chat. (The fantastic world of dreams is apparently more tolerant of verbal nonsense—think of someone remarking in a dream, “Colorless green ideas sleep furiously”). The underlying formal structure of language lends itself to a variety of possible modes of performance—not just within external communicative speech but also across other types of linguistic reality. Sounds (and signs) are not the essence of language by any means. 

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Is the Mind Identical to the Brain?

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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.

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