rigid, while the reference of the description is flexible. And that should be enough to show they are not synonymous.
Epistemic Arguments against Descriptivism
The epistemic argument is that one can be able to use the name Gell-Mann to refer to Gell-Mann even if one can provide no true uniquely identifying description of him. All X may be able to say is that
(1) Gell-Mann is a famous physicist.
which does not distinguish him from Steven Weinberg, while all Y may be able to say is that
(2) Gell-Mann is the physicist who unified the electromagnetic and weak forces.
which is false of Gell-Mann but true of Weinberg. Yet X and Y, for all their ignorance and error, are both referring to Gell-Mann, one saying something true but uninformative about him, the other saying something false about him.
So even if we allow that the meaning of a name may vary from person to person and time to time, no uniquely identifying descriptive meaning need be associated with the name by a given person at a given time. Nor is there any reason to suppose X or Y has some implicit knowledge that might be brought out by a dialectic of analysis: (1) and (2) may be all they have ever heard about Gell-Mann. Exactly similar considerations apply to common names: X may only be able to say that tin is a grayish metal or semimetal often used for plating or in alloys, which does not distinguish it from zinc. Y may only be able to say that tin is the second ingredient after copper in the alloy brass, which is false of tin but true of zinc.
If an associated uniquely identifying descriptive sense does not determine what person or substance or other item a proper or common name refers to, what does? Kripke offers a picture of an historical chain of communication, as he calls it, on which an item is picked out — say by pointing at a person, or at a sample of a substance, or whatever — and a name assigned it by a so-called initial baptist, and then the name is passed from speaker to speaker, each adopting it with the intention of using it to refer to what the speaker from whom the name was adopted was using it to refer to. No uniquely true noncircularly identifying information need be passed on along with the name.
Against the modal argument it is often suggested that we could take Aristotle to mean, not the teacher of Alexander but the person who actually did teach Alexander, by inserting actually — or rather, by making the verb explicit, and putting it in the indicative mood — and thus rigidifying the description, as it is called. This knocks out one reading of It could have happened that Aristotle did not teach Alexander leaving only the reading on which Alexander denotes the same person in the hypothetical contrary-to-fact situation as in the actual situation.
Against the epistemic argument it is sometimes suggested that there is at least one thing X and Y could say that would be uniquely true of Gell-Mann.
(1) Gell-Mann is the bearer of the name Gell-Mann.
One really should add here as used in the present discussion, or something of the sort, since presumably Gell-Mann has relatives who share the family name; but let the phrase as used in the present discussion be tacitly understood, and grant that (1) is uniquely true of Gell-Man.
Still it does not identify him. Simply knowing that everyone associates with the name Gell-Mann the description (1) cannot suffice to identify who Gell-Mann is, anymore than the inhabitants of an island can support themselves by, as the phrase goes, taking in each other’s washing. The adherent of the metalinguistic theory, as the view that a name N means that which bears the name N is called, will need some account of what determines the reference of names, if not a descriptive sense associated with them. But there is no obvious reason why such an adherent cannot simply appropriate Kripke’s historical picture.
A little thought shows that rigidifying by inserting actually does not help with the epistemic problem: if one has an identifying description, rigidification may solve the problem about its denoting the wrong thing when speaking of other worlds; but for this one cannot be so far sunk in ignorance and error as to lack an identifying description to rigidify. A little thought also shows that going metalinguistic does not help with the modal problem, since a different person might have borne a given name than the one who actually does bear it.
If we put on both patches at once, however, we are left with one surviving candidate as the potential descriptive meaning of Aristotle or Gell-Mann or tin, thus:
the individual who actually bears the proper name Gell-Mann
the substance that actually bears the common name tin There are still problems, but I will end my summary of Kripke and his critics on reference here, and return to our zombies.
The Bearing of These Issues on Zombies
At the end of the last chapter we were left with the question whether tin admits a definition that, when added to a complete description of the world in basic physicalistic terms, would imply that tin has atomic number 50. Our recent discussion leaves only one candidate definition standing: that tin is the kind that actually bears the common name tin, or more simply:
(1) Tin is what tin refers to.
What we now want to know is whether, when (1) is added to , the conclusion is conceptually implied that tin is the element with atomic number 50. The answer depends on whether, when conceptual truths about reference are added to , the following is implied:
(2) Tin refers to the element with atomic number 50.
We may suppose to include or imply information about what kinds of sounds are emitted by what kinds of organisms where, and so on. The question thus is whether when conceptual truths about reference are added to such information, (2) follows.
That depends ultimately and crucially on whether some kind of physicalistic analysis, perhaps neuralistic but more likely functionalistic, of the notion of reference can be produced — or can plausibly be supposed to exist already, implicit but psychologically real, in speakers.
Kripke himself is adamant that his picture is only a picture, and certainly not a reductive analysis permitting reference to be defined in physicalistic terms. Could something more be made of the historical chain of communication picture than Kripke himself does or thinks can be done?
If so, there may be some hope of sustaining a physicalistic analysis of reference; if not, the un Kripkean line of dualistical argument seems to falter. That is perhaps as far as the issue can be followed without getting deeper into contentious issues about theoretical apparatus, Kripkean and Chalmersian-Jacksonian.
I will only remark that, if the un-Kripkean wants to adopt, say, a functionalist analysis of reference, it will probably not be easy to reject a functionalist analysis of belief. To exhibit any weakness towards functionalist analyses of belief — what I call being softcore — is to provide an opening and even an invitation to counterarguments turning on the assumption that zombies can have beliefs, as I have in effect noted earlier. There is one well-known such challenge from Katalin Balog, but I will not pursue it, and possible softcore responses to it, here.
Back to Kripke
Rather than pursue further objections to the un-Kripkean dualistical approach, I will turn now to Kripke’s own discussion, which as I said has been somewhat eclipsed by such newer developments.
But first I should review a wider range of his examples of aposteriori necessities:
(1) Bronstein and Trotsky are the same person.
(2) Gorse and furze are the same plant.
(3) Tungsten and wolfram are the same substance.
(4) Nero was descended from Augustus.
(5) Whales are descended from therapsids.
(6) The Colossus of Rhodes was made of copper among other ingredients.
(7) Ethanol is made or consists of carbon among other ingredients.
(8) Light consists of electromagnetic radiation.
Here (1), (4), and (6) involve proper names of individuals, the rest common names of kinds of creatures or substances. (1)-(3) involve identity, (4)-(5) pedigree, (6)-(8) constitution. The tin example can be construed as another constitution example, the atomic number of an element being now understood as the number of protons among the component particles of each of its atoms.
All of (1)-(8) are widely accepted to be nonconceptual, synthetic, aposteriori, empirical discoveries; there is some dissent about the identity examples on the part of Scott Soames, Nathan Salmon, and others, but I will leave that issue aside, being more interested in the other cases.
The general form of the examples is C is R related to D, where C and D are names, proper or common, and R the predicate for some relation: identity or being the same as in some, being descended from in others, being in part made of in yet others.
It has been granted that it is aposteriori, an empirical discovery, that C is R related to D, and Kripke wants to claim that it is also necessary:
(9) It could not have failed to be the case that C was R related to D.
Kripke claims that on his views about naming, (9) reduces to the following, which does not involve names or descriptions at all:
(10) If two items are R-related, they could not have failed to be so.
And he claims that (10) is true in the case of the identical-with and descended-from
and made-in-part-of relations.
For identity this is indeed almost immediate. To say two items are identical is to say that they are not two but one, and to ask whether they could have failed to identical is thus to ask whether that one item could have failed to be identical with itself. But no item can fail to be identical with itself. For the other relations, additional intuitions have to be evoked and invoked, to which I will return in due course.
It is significant that descriptivists replying to Kripke generally accept the reduction of the necessity of (9) to (10) and the truth of (10) and hence the necessity as well as the aposterioriness of all the Kripkean examples. What they claim is that Kripke’s views about naming are not needed to achieve this result, but that all this can also be explained on their descriptivist principles. This is an issue that need not concern us here.
For us, the important point is that Kripke’s necessity claims are not widely disputed, at least not compared to what is for us his crucial nonnecessity claim, that the and states could have failed to be correlated, or to revert to the usual pretence, that being in pain and having C fibers that are firing could have failed to be correlated.
The neuralist wants to add to the list of aposteriori necessities the following, which Kripke insists is not like his examples:
Being in pain consists of having C fibers that are firing.
And how are the Kripkean examples supposed to differ from this new, antizombie example? What K feature is supposed to be present in the former and absent in the latter?
There are two answers in Kripke, one explicit, the other implicit. The Kripkean examples all concern impossibilities with a tendency, if looked at the wrong way, to appear possible. In his third Naming and Necessity lecture, Kripke explicitly offers an explanation for the illusory appearance of possibility in his examples, an explanation he explicitly denies would be available in the zombie case. In his notes and addenda one can find implicit hints towards an explanation of the necessity in Kripke’s examples, one that again would not be applicable in the zombie case. I will take these both up in turn.
Our Illusion of Possibility
Kripke in the Naming and Necessity lectures tries to explain how the necessity of examples of the kind he discusses could have been overlooked for so long, and why when he presented such examples in seminars in the mid-to-late 1960s there was usually some initial resistance to them. The kind of example he most closely considers is perhaps best represented by light consists of electromagnetic radiation — never mind what electromagnetic radiation itself consists in, whether waves or particles or both or neither.
The reaction he wants to diagnose and explain is that represented by those who on first hearing him protested: but surely light could have turned out to be, or could have been discovered to be, something else. Kripke’s view is in effect that one can only discover what is there to be discovered, and since light does not consist of anything but electromagnetic radiation, it could not after all have been discovered to consist of something else. He is not content, however, simply to say that could have turned out is an idiomatic expression of some epistemic rather than metaphysical modality, or that because English uses very similar forms of words to express epistemic and metaphysical modalities, it is easy to confuse them.
Rather, he attempts to explain what he considers the mistaken feeling that light could have consisted of something other than what it does, by positing that the world really could have been such that there were creatures in it in exactly the same epistemic position in which human beings found themselves before certain discoveries — creatures having like us eyes and vision and something needed for vision they called light, streaming down to their planet from the star around which it revolves — but in which what was called light was not electromagnetic radiation.
The Mistake to Be Avoided
The easy-to-make mistake here would be to conclude that the world described is one in which light is not electromagnetic radiation, while the correct assessment, according to Kripke, is that it is one in which light is used to denote something other than light. The subtle point about reference here is that with a word like light, even when we are speaking of a nonactual possible world, the word as we use it denotes the very same stuff it denotes when speaking of the actual world: even when we are speaking of a way the world isn’t but could have been, the word as we use it denotes the very same stuff it denotes when speaking of the world the way it actually is —and not the stuff it would be used to denote by the inhabitants of the world being spoken of. That is what so-called rigidity as opposed to flexibility amounts to in this instance.
What Kripke claims is that in each of his examples, where some aposteriori p is necessary, the following condition is met:
(1) The world could have been such that there were in it creatures in an epistemic state just like the one we were actually in prior to certain discoveries, in whose mouths the form of words we use to express the truth that p would have expressed a falsehood instead, because some key term would have denoted something different in their mouths from what it denotes in ours.
The illusion that p could have been false is explained as a confusion over what the form of words we use to express that p when speaking of how things actually are expresses when we use in it speaking of some counterfactual situation. What the form of words expresses when we are speaking of such a situation is confused with what it would express when creatures like us were speaking in the counterfactual situation in question.
The condition or candidate K feature (1) is rather a mouthful, but its content should become clearer on thinking through the example already given in slow motion: the world could have been such that there were in it creatures in an epistemic state just like the one we were actually in prior to modern scientific discoveries about the nature of light, in whose mouths the form of words we use to express that light consists of electromagnetic radiation, namely, the words light consists of electromagnetic radiation, would have expressed something false — because though the creatures would have used light in the same visually observable circumstances in which we actually use it, what they were using it for would have been something other than electromagnetic radiation, something that played the role in their visual observations that electromagnetic radiation plays in ours.
The illusion that it is possible that light could have consisted of something other than electromagnetic radiation is then explained as a result of misdescribing the envisioned possibility, using the key term light as if it were flexible when as a matter of actual fact it is rigid.
To sum up, Kripke’s story is as follows:
Being in an epistemic situation like ours, the hypothetical creatures would be aware of something playing the role in their lives that light plays in ours, and would call it light, but in so doing they would be using light to denote something other than light, which is to say, something other than electromagnetic radiation of certain frequencies.
It may take some work to think through what the claim Kripke’s candidate K feature (1) is not present in the zombie example amounts to.
How the Case of Pain Differs
The neuralist wants to claim that it only seems to be possible that C-fibers could have been firing without pain being felt, though really it is impossible, owing to the supervenience of pain upon C fiber firing. The possibility of C fiber firing without pain is, according to the neuralist, an illusion.
How would one attempt to explain this alleged illusion along the lines on which Kripke explains the illusion that light could have consisted of something other than electromagnetic radiation? The claim would have to be that the world could have been such that it contained creatures in an epistemic situation just like the one we were in prior to certain discoveries, in whose mouths C fiber firing does not occur without pain was false, because for them, pain did not refer to what it refers to for us.
The story would have to be, by analogy with that for light, as follows:
Being in an epistemic situation like ours, the hypothetical creatures would be aware of something playing the role in their lives that pain plays in ours, and would call it pain, but in so doing they would be using pain to denote something other than pain, which is to say C fiber firing.
And this is the claim that Kripke is at pains to deny. He denies the genuine metaphysical possibility, or indeed even the coherent conceivability, of a world epistemically indistinguishable from our world, but in which what was called pain was not really pain. The reason for the denial is that anything that could legitimately or plausibly be called epistemically indistinguishable from being in pain would have to be something that could be said to be felt as being in pain; but anything felt as being in pain is being in pain and nothing else.
That is because being in pain is having a feeling, and it displays ignorance of the meaning of the word pain to think it is anything else. To seem to be in pain is to be in pain. All that glitters like gold is not gold, but all that hurts like pain is pain. As Kripke has sometimes liked to put it, there can be fool’s gold, but no fool’s pain.
We have here, however, I’m very much afraid, an instance of what I hinted earlier would be coming: an argument over supervenience that ends up turning on just the same sorts of considerations — in this case, considerations about classification, and in particular, about the classification of being in pain as having a feeling — as the direct dualist argument for the conclusion that neuralism is a conceptual confusion.
If the direct arguments breaks down in a mere slinging back and forth of intuitions, plus perhaps some tossing around of contrary assumptions about the locus of the burden of proof, the indirect argument seems here to be threatened with a similar breakdown, with the added complication that it involves — or would involve, in a fuller account that I have been offering — a good deal of contentious apparatus.
Our Knowledge of Necessity
It is fairly common for metaphysicians today, especially of the school who go in for complex views about the fancy notions they call essence and grounding, to be rather unconcerned with questions about how we can know this or that metaphysical claim is true (questions about the “epistemology of modality”). One well-known figure has even been quoted as coming out with the slogan epistemology last if ever, though as I have not been able to find that phrase in print, I will name no names. For all one could tell from the Naming and Necessity lectures, Kripke’s attitude might have been similar.
The addenda provided when the lectures were published show otherwise, and by contrast do take the question how do we know? seriously, though Kripke’s formulations in the direction of an answer are extremely cautious and heavily guarded: it is not a matter of presenting a solution, but of presenting what he says are hints as to what may be a solution.
A less cagey writer might have put the matter differently, directly suggesting that in all the Kripkean examples of aposteriori necessities, it is a conceptual truth that if p is true, then it is necessarily true. That p is true is an aposteriori, empirical discovery, but that necessity comes with truth is knowable in advance of scientific investigation.
The Goldbach Example and Others
Kripke hints towards such a suggestion in connection with the Goldbach example. Here the conceptual truth would be that mathematical facts always hold of necessity. But is it indeed plausible to regard this as a conceptual truth? Is it plausible to regard this as something reflecting a semantic rule or linguistic convention?
It seems pretty clear what the linguistic rule would have to be: distinctions of grammatical mood are not applicable to purely mathematical statements. In other words, purely mathematical facts count as necessary because, or in the sense that, there is no significant distinction marked by the contrast between could have been and is and could not have failed to be in the mathematical realm.
Well, this formulation somewhat overstates the rule, which would rather be that distinctions of mood are not applicable if taken in a metaphysical rather than an epistemic sense. The best evidence for the existence of such an implicit rule at work in our language would seem to be the fact that when modal distinctions are applied to purely mathematical matters, as does sometimes happen, they are generally interpreted without hesitation as being meant epistemically rather than metaphysically.
(1) Theorem (Euclid): There is no largest prime.
(2) Proof (by reductio): If there were a largest prime N, then…
Clearly what the mathematician is saying in (1) and (2) here is not something metaphysical like this:
You know what the actual mathematical facts about primes are, and in particular that there is no largest one, since I have just told you; but imagine an alternate reality in which the mathematical facts are different.
Rather it is something epistemic like this:
I’ve just asserted something, but you don’t know it’s true, because I haven’t yet proved it; so imagine that, despite my having just asserted it, and my being generally reliable on this subject matter, it is false.
Similarly, if we are told that possibly Euler’s constant is rational and possibly Euler’s constant is irrational, we take understand this to mean, not that there are alternate mathematical realties, in one of which the constant is rational and in the other of which it is irrational, but merely that it hasn’t been proved to be irrational, and hasn’t been proved to be rational, either.
Another case, not discussed by Kripke, where a supervenience claim is widely granted is that summed up in the slogan the moral supervenes on the natural. But a slight preliminary clarification is needed here. For most who advance this slogan do not really mean it. Taken literally the slogan would seem or threaten to imply that supernaturalistic theories of morals — so-called divine command theories and the like — are not just false but impossible; but while the sloganeers may or may not believe this, even if they do believe it, it pretty clearly isn’t part of what they intend to assert in advancing the slogan. Rather, the slogan should be something like this: the evaluative supervenes on the non-evaluative.
The thought is that whether, say, some act is right or wrong, is completely determined by the features of the act and its situation and consequences and so forth that would be describable in neutral, value-free terms. If the act and its situation and consequences and so forth were unchanged in every respect so describable, its moral status would necessarily remain the same.
Can this be regarded as a conceptual truth, extrapolating from Kripke’s hints? Perhaps it could be excogitated from close consideration of the very idea of an evaluation, which seems to presuppose that there is first something there to be evaluated, before one then evaluates it. But I only put the question, as a test case, by way of illustration. If this book is not the place for any extended excursion into philosophy of mathematics, still less is it the place for any extended excursion into metaethics.
What we really need to consider is what sorts of conceptual truths might be the ultimate source of the necessity — or anyhow, of our knowledge of the necessity — in the kinds of examples listed in the preceding section, and whether a similar truth could serve as a source of necessity in the case of the correlation of pain with C fiber firing.
Possible Worlds Jargon
Kripke popularized world talk in his early work on the formal logic of modality, but had distanced himself from it somewhat by the time of the Naming and Necessity lectures, though he never switched over entirely from speaking of multiple worlds to speaking exclusively of multiple states that the world could have been in— the one and only world there is, setting aside talk of a world to come as not relevant to the present discussion.
Possible-world talk involves dropping the kinds of distinctions of grammatical mood we usually make, so that instead of saying such-and-such could have been [subjunctive] the case if the world had been other than as it actually is, one says such-and-such is [indicative] the case in some world other than the actual one.
The switch raises certain questions that don’t arise without it. For instance, if instead of saying, I could have taken today off, I say, there is a possible world in which I have taken today off, a question arises about the relationship between the I in this actual world, who has not taken the day off, and the I of this other world, who is taking the day off.
As Ambrose Bierce says somewhere, conception of two myselfs is difficult. Can I myself really be present both in this actual world and in some other world? Or must I think that what is over there is not really me but only a so-called counterpart or Doppelgänger of me? Or that I am stretched out in a modal dimension in addition to the three spatial dimensions, with only a slice of me here and a slice of me there, as when I stand on a bridge over the Delaware River between Lambertville, New Jersey and New Hope, Pennsylvania, looking down the river, one side of me may be in one state and the other side in the other?
To take possible worlds talk seriously, as did Lewis, is to take such questions seriously. Such issues do not arise if one sticks to saying that the way the world is, I did not take [indicative] today off, but the world could have been such that I took [subjunctive] the day off. With that usage, there is no question of there being more than one I, one taking the day off and one not; there is only one I, who actually is not taking the day off, but who could have done so.
Engaging like Kripke in possible worlds talk only as a picturesque manner of speaking, without taking it seriously, amounts to being willing to fall back into the usage that restores distinctions of grammatical mood, and concerns different ways the world could have been, different states the world could have been in, rather than different worlds, whenever the possible-worlds jargon threatens to raise puzzles. I will here, as I claim Kripke in effect does, always consider a question of the form, is such-and-such an individual who exists in this or that possible world the same as thus-and-so an individual who exists in the actual world? to amount to would such-and-such an individual who would have existed if the world had been this way or that way have been the same as thus-and-so an individual who exists in the world as it actually is? My suggestion will ultimately be that the source of Kripke’s pedigree and constitution examples must be sought in such questions and the criteria used to answer them.
Criteria of Transworld Identification: Pedigree
In publishing the transcript of his lectures, Kripke added some footnotes, and we must turn from the addenda to these if we are to get any help from Kripke with the questions we were left with at the end of the preceding section. Kripke says that what appears in some of these notes are words actually spoken in his talks, as asides. He does not tell us which notes these are, though any that cite literature from after 1970 must surely be later additions and not asides. The one footnote that will most interest me (number 57, from which I quote below) is one of these.
Philosophers tend to leap at once to questions about the world having been different from the beginning of time, and I suppose that one must do so in connection with the examples about constitution. But with the examples about pedigree, and others as well, it is enough to imagine running the engine of history in reverse back to a certain time, and then running it forward again along a different track. Apropos of this matter, Kripke says:
…ordinarily, when we ask intuitively whether something might have happened to a given object, we ask whether the universe could have gone on as it actually did up to a certain time, but diverge in its history from that point forwards so that the vicissitudes of the object would have been different from that time forth.
This is the method Kripke uses when arguing that the name Aristotle cannot be an abbreviation for some description of one of the Stagirite’s famous deeds, such as the teacher of Alexander. We backtrack to Aristotle’s youth and imagine him going into the family business, rather than pedagogy, and conclude he need not have become the teacher of Alexander.
In pedigree examples, Kripke notes, in the same footnote from which I quoted earlier, that the time at which the divergence from actual history occurs may be sometime before the object itself is actually created. This is what would be at issue if we asked whether Nero could have had a different mother from the one he did, or whether that mother, Agrippina the Younger, could have had a different mother, or whether that grandmother, Agrippina the Elder, could have had a different mother, or whether that great-grandmother, Julia, could have had a different father from Augustus. We imagine a situation some time before the scandal-shadowed Julia’s birth or conception developing in a different direction from the one the course of history actually took, and resulting in the birth of a certain girl, and we ask whether she, that baby girl, would have been Julia.
Kripke suggests that really the only obvious things we have to go by are the gametes from which the zygote that became Julia were formed. If the same egg and sperm had united, we will say it would have been the same Julia, and if not, not. In a later work on first-person pronouns, Kripke adds an anti-Cartesian gloss:
If we had a clear idea of the soul or the mind as an independent, subsistent, spiritual entity, why should it have to have any necessary connection with particular material objects such as a particular sperm or a particular egg? A convinced dualist may think that my views on sperms and eggs beg the question against Descartes. I would tend to argue the other way; the fact that it is hard to imagine me coming from a sperm of egg different from my actual origins seems to me to indicate that we have no such clear conception of the soul or self.
When we start at some early stage in the actual life of someone like Aristotle, and imagine various lines on which history might have moved forward from that point, we have available criteria to tell us whether this or that person later in the story, such as the one who becomes teacher of Alexander, would or would not have been Aristotle. They are the same criteria for identifying persons over time that we employ when we imagine possible courses events may take over the next year or decade, and ask whether this or that person later in the story, such as the one who holds the office of U.S. president in 2020, is or is not Donald Trump.
When we start before the birth or conception of a given individual, criteria are harder to come up with, and Kripke finds none that go back very far before conception. The main point for present purposes is that it is on criteria of identity that he is ultimately relying in his judgments of possibility.
Though it is extrapolating beyond anything Kripke says explicitly about his examples, if there is a conceptual truth in the background behind those that turn on genealogical or ontogenic pedigrees of individuals and the evolutionary or phylogenic pedigrees of species, I would guess it must be something like this:
If an individual or group that actually exists actually had a certain ancestry, then any individual or group there is or could have been that has or would have had a different ancestry, does not count or would not have counted as the same individual or group.
So much, then, for pedigree; it is time to take up what seems the most obscure and difficult case.
Criteria of Transworld Identification: Constitution
Kripke has less to say about what kind of conceptual truth might be behind aposteriori necessities about constitution, and I am not in a position to make any exegetical claims about his intentions. So I am extrapolating further than in the pedigree cases when I suggest that the principle at work may be something like the following, and that I for one can think of nothing else that it might be:
(1) If a substance that actually does exist actually has a certain constitution, then any substance there is or could have been that has or would have had a different constitution, does not count or would not have counted as the same substance.
Thus if alcohol — I mean ethyl alcohol or ethanol — actually is a compound of carbon and hydrogen and oxygen in a ratio of two to six to one, then a substance actually found on some other planet, or a substance that would have been found on this one if the world had been very different from the way it actually is, is not or would not have been alcohol if it has or would have had any different chemical constitution, not even if it induced exactly the same degrees of intoxication with exactly the same degrees of consumption in the people — or whatever was there in place of people — who consumed it.
A possible substance in a possible world that had a different chemical constitution would not be alcohol. Contraposing, turning this around, in any possible world, a possible substance there that was alcohol would not have a different chemical constitution from what alcohol has in the actual world. Or in other words, whatever chemical constitution alcohol actually has — supposing it does actually have a uniform constitution — it has in any possible world where it is present: it could not possibly have had a different one, it has the one that it has of necessity. And this is knowable in advance of empirical investigation, simply by understanding and internalizing that something like (1) is a semantical rule or linguistic convention of our speech.
To return to the issue of a K feature, supposing the Kripkean examples generally work as I have suggested, with something on the order of (1) in the background as a conceptual truth adding an element of necessity to whatever is empirically discovered, boosting aposteriori truth to aposteriori necessity, the Kripkean claim would be that nothing like this would be available to raise the correlation of pain and C fiber firing to the status of a necessary truth. For the analogue of (1) in this case would have to be something like this:
(2) If a psychological state that actually occurs actually has a certain neural correlate, then any psychological state there is or could have been that has or would have had a different neural correlate does not count and would not count as the same psychological state.
But no such principle can plausibly be claimed to be a conceptual truth. What makes psychological states, or anyhow conscious ones, and especially sensations, count as the same are such factors as who is the subject of them and when the time of their occurrence and what is their so-called phenomenal character, what it is like or feels like to be subject to them.
One would have to be grossly mistaken about what makes for sameness of sensations to think that something like (2) held as a semantical rule or linguistic convention, making the identity of a state as one of being in pain dependent on what underlies it physically or neurally — or, I would add, what role it plays functionally as an intermediary between stimulus and response, though having more or less dismissed functionalism from further consideration some time back now, let me not elaborate on this point.
Grounds for Disappointment
It is only too obvious, however, that if our last candidate for a K feature is really what is at work, and this consideration has to be appealed to in order to resolve the supervenience question, then what has to be appealed to in order to resolve the supervenience question are exactly the same considerations that would be involved in a direct confrontation between dualism and neuralism, with the dualist diagnosing conceptual confusion on the part of the neuralist. If that debate was at an impasse, the detour through modal considerations has not after all taken us around it, but rather has brought us right back to it after forcing us to make a long circuit.
The promise of the supervenience issue to provide a way around or work-around has proved false. Worse, the detour has exposed us to certain dangers. For we have been exposed all along the way to the threat of becoming bogged down en route in obscurities about reference or especially about modal apparatus. The latter threat, at least, I have tried to ward off here mainly by keeping well back from the quicksand that surrounds the modal route on either side. I have played down the role of any theory of possible worlds that takes them seriously and not as mere manners of speaking, resolutely ignoring the debate over the nature of possible-worlds apparatus between the un-Kripkeans Chalmers and Jackson on the one hand, and Kripke and supporters like Soames on the other hand.
This has, indeed, made my account something very much less than a full scale survey of the status quæstionis, or what the cognoscenti might have been led to expect from the title of this book; but I hope I have shown enough of what is going on to explain why I do not want to show more.
The complaint about the supervenience issue that I have just been voicing, to the effect that it is a pointless detour, is as I hinted earlier only one of three that I have, and perhaps of the three it is the least serious.
For I will next be suggesting that the supervenience issue has been serving as a pernicious distraction from the issues that really matter. In the process I will be suggesting that the most important division among philosophers today on the mind-body problem is not the one marked by the supervenience thesis, which is the division between dualists and physicalists.
Rather, it is a division whose dividing line runs through the physicalist side; only it is not the one division over on that side that I have mentioned so far, the division between neuralists and functionalists, but another. But to say just what it is will take some background preparation, filling in a gap in my exposition thus far. For it is a defect of many discussions of the mind-body problem that they go on about the distinction or alleged lack thereof between mental and physical without ever spelling out just what the adjective physical connotes, and my own account has suffered from this deficiency up to this point.
VI The Bounds of Physicalistic Science
In order to arrive at a more definite view of what it is that we are contrasting, as physical, with sensation and affect, we will need to revisit Descartes.
The only worse procedure than offering no preliminary account whatsoever of the nature of the physical is to dispose of the issue quickly and cheaply by saying that the physical is what is studied by physics, which is to say, by the science done in physics departments. To take that line is to hold an important philosophical distinction hostage to the convenience or the whims of academic administrators. Indeed, it is to do worse with the question than academic administrators typically do, since they at least often place their physics departments inside schools of physical science, along with chemistry, astronomy, geology, and more, thus implicitly recognizing that there is something that may be called a physicalistic character to a range of sciences extending beyond what is conventionally recognized as physics proper.
But this character, I would submit, extends well beyond schools of physical science into the life sciences, embracing not only molecular biology but even evolutionary biology as well. To know where to draw the line, we need to go back to the beginning of the period when natural science was separating from natural philosophy, and physics was ceasing to be the name of a branch of philosophical speculation, and becoming the name of a branch of scientific research, and to a certain distinction made not only by Descartes but in one way or another by his older and younger seventeenth-century philosophical and scientific contemporaries and successors, notably Galileo Galilei, Robert Boyle, and John Locke.
All in one way or another make a distinction between a list of properties or qualities of things they considered in some sense more objective or real, and a list of those they considered more subjective or apparent. The distinctive labels, if any, used for the first list and the second list varied from writer to writer (though “primary and secondary qualities”, introduced by Boyle and popularized in a modified sense by Locke, has won out in subsequent discussion). So did the account, more extended in some writers than others, of the principle of division.
And so did the lists of examples of the two kinds, though generally size and shape would be mentioned at the top of the first list, and color high up on the second. The features on the first list were those on which the new science was to focus, and it is notable that they are all such as to lend themselves pretty straightforwardly to mathematical treatment. Thus making the division was important to the new direction science and especially physics was to take over the centuries to come, a direction that has been mentioned from early on in this book, but whose full significance we have yet to ponder.
Speaking of Color
No philosopher today can be quite happy with the diction of the various seventeenth-century worthies in marking their division. Perhaps the language of color would raise the most objections. In ordinary language we distinguish between appearance and reality when using color terms. Thus we may say that what appears a uniform orange patch on the picture just now coming out of the printer is really made up of tiny red and yellow dots, as can be seen with a magnifying glass. More generally, we apply the same color vocabulary when speaking of purely subjective phenomena such as what we see when we close our eyes in a lighted room — a changing view we have no inclination at all to take to be a view of anything in front of our eyes, be it a gas in the room before us, or the back of our eyelids — and when speaking of something objective present even in objects never seen — as with our belief that our gallbladders are greenish, though most of us never have been nor will be opened up to show that organ.
This looseness in ordinary language can be a source of confusion, since when a dualist claims that one cannot really know what the state of seeing red is like without having been in the state, this may be misunderstood as meaning that one cannot really know what the state of seeing red is like without having seen an external red object, whereas it would suffice to have seen an internal red image.
Early modern thinkers tended to regiment the language of color in the direction of restricting it to the subjective. To do so was a mark of following strict scientific rather than loose lay usage — or in the terminology of the period, of following the learned rather than the vulgar. The classic expression of this attitude is found in Newton’s Opticks (First Book, Part II, Experiment VI, Definition):
And if at any time I speak of light and rays as coloured or endowed with colours, I would be understood to speak not philosophically and properly, but grossly, and accordingly to such conceptions as vulgar people in seeing all these experiments would be apt to frame. For the rays to speak properly are not coloured. In them there is nothing else then a certain power and disposition to stir up a sensation of this or that colour.
In putting color on the second list, it was not intended that whatever it is in external things that is responsible for — to use Newton’s language, their power or disposition to stir up — the sensationsof the relevant kind in us should be placed outside the boundaries of physics. The intent was at most that it was to play no immediate role, the hope and belief being that it would prove to be some combination of features on the first list, and as such measurable and mathematically treatable through them.
What was being excluded — and the word is crucially important, for this was not some inadvertent oversight but indeed a deliberate exclusion, and one central to the program and project of the new science — when color is set down on the second list, is the sort of thing I have been referring to when speaking of red looking like THIS, or what colors look like. That is how the regimented usage must be understood, despite the fact that many philosophers today, I have said, would disapprove of such regimentation of color terms towards subjectivity, and some even prefer a regimentation in the opposite direction.
Speaking of Size and Shape
As for the first list, contemporary critics already noted that with size and shape, too, we in ordinary language distinguish real from apparent, though with these features there are not one but two sensory channels through which they appear, visual and tactile, and the link between sight and touch is not directly sensed. (This fact gave rise to the seventeenth-century thought experiment known as the “Molyneux problem”, only recently apparently empirically resolved.) Now what a shape looks like or what a shape feels like are really intended to be excluded quite as much as what a color looks like, and in this respect the placement of shape on one list and color on another is misleading.
But again to use Newtonian language, whatever it is in external things that is responsible for their power or disposition to stir up visual and tactile sensations of shape was intended to be directly admitted in the new science in a way that whatever it is in external things that is responsible their power or disposition to stir up visual sensations of color or auditory sensations of pitch was not. Behind the distinction was the perhaps inchoate thought — on which the criticism of the immaterialist George Berkeley focused — that in the one case but not the other whatever it is in external things could be said to resemble the sensation stirred up.
Descartes’ first or good list consisted of geometric and kinematic features: size and shape, as already mentioned, and motion, that is, speed and direction of displacement, at least in a relative sense. Important physical quantities, such as Newton’s notion of mass, that must be considered along with the geometric in statics, and along with the kinematic in dynamics were not given their due.
But even Newton’s list would have failed to note some features any present-day physicist would be sure to include. For a version of the first list today would have to admit many features not recognized until a century or two or three after Newton, and not accessible through any sensory channel, down to the so-called charm and strangeness of quarks, all in the end posited to explain what is sensible.
But the subsequent development of physics, though it has admitted many such unobservable theoretical properties, as philosophers call them, has not undone the original exclusion of qualities accessible through a single sensory channel: what colors look like and what pitches sound like, or in jargon, the phenomenal character of visual and auditory experience.