How Many Minds? [This paper was written sometime in, or shortly after 1984. No one wanted to publish it. I still think it may make a modest but useful contribution to the metaphysics of minds.] Relevant Reading: Hilary Putnam, "Robots: machines or artificially created life?", The Journal of Philosophy, LXI (Nov. 1964), 668-91. Reprinted in Putnam's Mind Language and Reality, Philosophical Papers Volume 2, Cambridge University Press, Cambridge, 1975, pp. 386-407. Putnam's discussion of 'hydra-headed robots' in RT&H, pp. 96-102. Hugh Chandler, "Indeterminate people", Analysis, Vol. 45. No.3, June 1984, pp. 14145. George Rea, "How many minds has a tredecim?", Analysis, ?? 1987. David Chalmers' page on Zombies. In the '84 paper, I suggested that there are physically possible creatures such that there is no fact of the matter as to whether or not they have minds. Hilary Putnam had argued for the same conclusion in "Robots: machines or artificially created life?", see especially ML&R pp. 404-407, and in R,T&H, pp. 96-102. A tredecim is a hypothetical entity made up of thirteen distinct animals. These animals form a symbiotic cluster. By hypothesis, there are at least thirteen minds at work here; but are there, perhaps, fourteen? Does the composite have a mind? When a tredecim breaks up into its components, the process seems to be very painful; but no component feels pain. My claim was that this is a case of genuine, non-epistemic, indeterminacy. We could decide that the tredecim's sobs and tears are caused by real pain; but we could equally well decide they are not. That's more or less the way I put it. George Rea found my story unconvincing. "Chandler's analysis does not convince me that there is any indeterminacy in this matter which is not mere fictional indeterminacy (i.e. author's indecision). Chandler has not analyzed what sorts of minds might exist in a tredecim. I intend to show that real differences within the mental life of a tredecim would determine the answers to Chandler's questions." (p. 101) It is certainly true that my description of the tredicims was sketchy. And it may well be the case that some understanding of what it is like to be a component of a tredecim is relevant to answering my questions. Nevertheless, I have the impression that Mr. Rea simply begs the question at issue (perhaps I did too). He describes three different tredecims and in each case he makes having or lacking a fourteenth mind part of the description. Let me make a wild guess here. My guess is that Rea thinks the term "mind" is indexical and not descriptive. He might also hold that the term designates something at least partially occult, or something not occult [e.g. a brain] provided the thing has certain occult properties. On this view of the matter, the idea that every possible entity either definitely has or definitely lacks a mind can appear almost inescapable. In my paper I hinted that this idea has embarrassing consequences. Let me amplify. Imagine a team of thirteen people who together work a 'person' program on Saturday afternoons. The 'person' they form plays chess, is interviewed over the phone, writes poetry, and so on. The point of the game is to pass as a person. In general, individual members of the team are quite unaware of the 'person's' behavior. They are too busy with their own very difficult computational tasks. This sort of case does not generate real controversy, does it? The 'person' is just a team made up of thirteen distinct people. There is no emergent fourteenth mind at work. [How do we know? Those who believe that minds are occult entities should, perhaps, be agnostics even here.] Now we can imagine a sequence of cases ranging from the team just described, through the tredicims, to a normal human being. No doubt the human has a mind. Hence the sequence ranges from an entity that plainly lacks a mind (or so I think) to an entity that obviously has a mind. But the changes as we shift from one case to the next can be absolutely inconsequential from the point of view of ordinary empirical investigation. Does the sequence yield borderline cases of 'having a mind'? Nagelian or Swinburnean realists in regard to the mental presumably hold that there are no borderline cases here. I'm assuming that Rea holds some such view. Hence, I assume he would say that it is possible that there should be two creatures, C1 and C2, that differ in some empirically inconsequential way [for example, in the size of one synapse] such that C1 has a mind (the 14th mind) while C2 doesn't. How could anyone believe this? As I have said, perhaps the idea is that there is something essentially occult about minds. At some point along the line there is a sudden, important, occult difference between creatures more or less alike in all features open to ordinary empirical investigation. Thus, for example, it may be the case that C1 has a crucial occult property, or appendage, that C2 lacks. It is this, and not the trivial overt difference between them, that makes it correct to say that C1 has a mind while C2 doesn't. I do not want to reject the possibility of such occult factors. But it seems to me that people lacking this sort of factor are also possible. That is to say, I am suggesting that there can be a sequence of creatures ranging from one that lacks a mind to one that has a mind and such that no creature in the series has any occult property or appendage. In regard to this kind of sequence, either we admit that there are borderline cases of the sort in dispute, or we find ourselves in the embarrassing position of having to claim that patently trivial differences can make it correct to say of one creature that it has a mind and of another that it doesn't. The embarrassment could be avoided if it could be shown that having a mind requires having occult properties or appendages. But how could this be the case? Here is one option. Perhaps a mind is necessarily a spirit, and spirits are at least partially occult entities. How could minds be spirits necessarily? Some philosophers hold that ordinary talk about the mental is incurably dualistic. On this view, analysis of the relevant language shows that if anything has a mind it must also have, or be, a spirit. (This is, or was, the view of Richard Rorty. Since we cannot, now, take spirits seriously, Rorty has said, we should give up the idea that there are minds.) My impression is that 'mind talk' is not so deeply committed to dualism. Might the necessity be natural? That is to say, is there a law of nature to the effect that spirits are the only entities that can think and feel? Well ... perhaps. Nevertheless, the best bet at the moment seems to be that there is no such law. A creature with an ample stock of beliefs and desires, but lacking a spirit, would not, apparently, violate the natural laws of our world. One last try. Perhaps the alleged necessity is 'metaphysical'. The theory might go as follows: (1) Within each ordinary human being there is a single spirit that does a lions share of the work in producing his or her rational behavior. [The effects of such a spirit may, in principle, be detectable. If this is so, then the spirit is not entirely occult.] (2) "Mind" is intended as a natural kind term rigidly designating that which in us is responsible for rational behavior. Hence, on this view, minds are necessarily spirits. The first of these two claims is certainly questionable; but we need not worry about that now. The second is at least equally open to attack. Suppose we intended the term "mind" as a rigid designator of things of the kind which in us generate rational behavior. Suppose, moreover, that our brains do the trick. In that case, minds would necessarily be brains. It would follow that spirits, and various other brainless, but apparently rational, entities must be mindless. This conclusion is totally unacceptable to many of us. We think it possible for a creature to lack a brain and yet have thoughts and feelings. [The robots in Isaac Asimov' fiction would be examples.] Apparently, then, we do not intend "mind" to be a rigid designator of the required sort. Assume for the moment that our rational behavior is caused by spirits. Now consider the "Zombies". They inhabit a world similar to ours. And their brains are much like ours. But no spirits are at work there. The zombies' rational behavior springs from their brains without spiritual aid. In fact, there is nothing occult about them. Nevertheless, they construct spaceships and other fancy artifacts. In addition, they 'laugh' and 'cry' as we do, and their response to what seems to be their 'jokes' seems to show a sense of humor like our own. When one interacts with them it is very difficult to remember that they lack minds, and that, from a moral point of view, they could be raised for meat. I think most people would agree that this story is grotesque. But where does it go wrong? One suggestion might be that what I have described is simply impossible. Entities lacking occult properties and appendages can't design and build spaceships. But why should we think this is true? Is there any good reason to accept this view? The more obvious solution is that the zombies do have minds that is to say, thoughts and feelings even though they lack spirits and all other occult features. But then "mind" is not necessarily coreferential with "spirit", even on the supposition that our rational behavior is spiritually generated. When we consider spirits, robots, zombies, and so forth, it seems clear that many, if not all, of us do not intend the term "mind" to be a rigid designator of the natural kind locally responsible for rational behavior. In fact, we think it possible for creatures of radically different metaphysical sorts to have thoughts and feelings. Thus there is evidence that "mind" is not an indexical term. But what else could it be? Perhaps creatures of a certain kind, Ks, can properly be said to have thoughts and feelings have minds if, and only if, Ks normally satisfy certain complicated, but specifyible, conditions. Very crudely, one requirement might be that adopting 'the intentional stance' (Daniel Dennett's phrase) towards Ks yields an abundance of diverse and accurate predictions about their behavior. But this cannot be the only requirement. Some of the creatures we have been considering show its insufficiency. By hypothesis, an assignment of reasonable beliefs and desires yields good predictions about the behavior of the 'person' constituted by members of the team that meets on Saturdays; but that 'person' does not have a mind. There must be at least one more requirement. I want to suggest that our sequences suggest a possible candidate. We seem to insist upon a considerable degree of unity in a creature that has a mind. If it is modular, its component modules must be deeply 'committed' [in some sense] to the composite. Both requirements (Dennett's and the 'unity' requirement) permit borderline cases. The actual world provides examples of creatures that fulfill the 'unity' requirement, but neither clearly satisfy nor clearly fail to satisfy the 'intentional stance' requirement [flies? frogs?] Tredicims certainly satisfy the 'intentional stance' requirement, but neither clearly have nor clearly lack the requisite unity.