|What Are We? Souls|
|Source: What Are We? A Study in Personal Ontology, Chapter 7 (November 2007: Oxford University Press.)|
|Paper - Abstract|
(OO-L): This chapter is about the view that we are simple immaterial substances–immaterialism–and related views. It is claimed to be best supported by the difficulty of saying what material things we could be. For instance, the paradox of increase threatens to show that nothing can have different parts at different times, and materialists can solve it only at considerable cost. Immaterialism is then shown to face grave problems concerning the relation of souls to material things. Compound dualism, Swinburne's view that each of us is composed of an immaterial soul and a material body, is shown to face difficulties in addition to those of immaterialism. The Thomistic view that we are hylomorphic compounds is shown to combine the problems of compound dualism with those of the bundle view. The views of Chisholm and Lowe that we are simple material things are then critically discussed.
- Traditional arguments for immaterialism
- The paradox of increase
- The cost of materialism
- Objections to immaterialism
- Compound dualism
- Simple materialism
7.2 Traditional arguments for immaterialism
- We might be immaterial substances: souls for short. Or each of us might have a soul as a part, along with something material: we might each be composed of an immaterial soul and a material body. I will consider this variant in §7.6.
- What is an immaterial substance? Not a sort of immaterial matter or stuff. A soul is a substance in the sense of something that exists in its own right and is not a mere state or aspect of something else. What it is for a substance to be immaterial is not easy to say. It may suffice to say that souls are immaterial in that they are not made up, even partly, of matter--the stuff that makes up sticks and stones--or that they lack mass, energy, temperature, electric charge, and other paradigmatically physical properties. This characterization has the disadvantage of being entirely negative: it tells us what souls are only by telling us what they’re not. Descartes and Leibniz tried to characterize souls positively by saying that their essence is thinking. They are mental through and through: their only intrinsic properties are mental properties. I don’t want to assume that. Clearly, though, souls as immaterial substances are supposed to have mental properties, even if they have intrinsic non-mental properties as well: they are supposed to be thinking substances.
- Most philosophers who believe in souls take them to be mereologically simple--that is, to lack proper parts. They deny that souls are made up of “smaller” parts that may belong to different souls at different times or exist without being parts of any soul at all. Likewise, souls are usually not taken to be made up of some sort of immaterial stuff that could exist without being formed into souls. It is certainly hard to imagine what the parts or the stuff of an immaterial soul might be like--more difficult even than to think about souls generally. And many of the arguments for the view that we are souls imply that souls are simple.
- Call the view that we are immaterial substances immaterialism. It is not the same as substance dualism: the view that substances come in two exclusive kinds, thinking immaterial substances and unthinking material ones. Immaterialism does not imply that there are any material substances (Berkeley was an immaterialist). Another difference is that according to substance dualism all thinkers are immaterial, whereas immaterialism says only that we are. For all immaterialism says, there may be material thinkers other than ourselves. It would of course be very strange to suppose that some thinkers are material but we are immaterial. Still, it is a possible view. Despite their differences, however, substance dualism and immaterialism are close cousins: most immaterialists are dualists, and most discussions of immaterialism, whether critical or supportive, assume the reality of material things, and are thus discussions of substance dualism.
- It would be an understatement to say that immaterialism is out of favor nowadays. Most philosophers of mind treat it as little more than a historical curiosity. Introductory textbooks dispense with it briefly in their opening pages, often citing objections that would be considered flimsy if they were directed against a more fashionable view. In the current intellectual climate the interesting question about immaterialism is not whether it might be true, but how the likes of Plato, Descartes, and Leibniz could ever have believed it.
- I will try not to be so dismissive. Immaterialism has its problems--plenty of them. But it also has hidden virtues. Its strength is the weakness of materialism. As I see it, that weakness is not the traditional problem of how a material thing could think or be conscious, but rather the problem of what material things we thinkers could plausibly be said to be. It is the ontology of material objects, not the nature of the mental, that makes trouble for materialism. One way to avoid that trouble is to say that we are immaterial.
7.3 The paradox of increase
- There are many traditional arguments for the claim that we are immaterial substances. These three are perhaps the most common1.
- The divisibility argument says that any material thing, or at least any that is a candidate for being a thinker, is divisible into parts. But no thinking thing could be divided into parts: the very idea of half a thinker--half a mind--is absurd. Thinkers, ourselves included, must therefore be simple, and hence immaterial.
- The argument from disembodied survival says that it is possible for me to survive in a wholly disembodied state. But no wholly material thing could survive in a disembodied state. Not only could no material thing become disembodied and remain a material thing, in the way that no white thing could become blue while remaining a white thing. More strongly, nothing can start out as a material thing and then stop being material and carry on existing in an entirely immaterial state. Anything that could become disembodied must be at least partly immaterial already. It follows that I am not a material thing. (It doesn’t follow that I am a wholly immaterial thing: I might have both material and immaterial parts. But for reasons we will come to presently, immaterialism is the most likely conclusion.)
- The third argument says that thinkers must be immaterial because we cannot account for the nature of certain mental phenomena in physical terms. We might call it the inadequacy-of-physicalism argument. One version goes like this: if we try to conceive of thought or consciousness arising out of the interactions of physical particles, we draw a blank. No matter how carefully we examine the workings of even the most complex physical object, we shall never see anything that could account for thinking or consciousness. This is not merely because we don’t fully understand the physical workings of the brain. It doesn’t matter what those workings are: as long as they are physical, it will be inconceivable how they could produce thought or consciousness. Hence, mental phenomena cannot arise out of the interactions of physical particles. But if any material thing could think, its thinking would have to arise out of the interactions of its physical particles. (What else could explain why only material things with a very special physical structure--things with brains--show evidence of thinking?) Therefore no material thing could think: we thinkers must be immaterial.
- If there is anything that the critics of immaterialism have got right, it is that these arguments are unpersuasive.
- The main premise of the divisibility argument is that no thinking thing could be divided into parts. But how can we know that without already knowing whether a thinking thing could be material? Suppose there were a material thinker: a biological organism, say. In that case we should understand well enough how a thinker could be divided into parts, and what the result would be. So unless we can rule out this possibility from the start, there is no evident reason to agree that thinkers must be indivisible.
- The second argument asserts that it is possible for us, but not for any material thing, to survive in a disembodied state. But why suppose that we can survive in a disembodied state? If we already knew that we were at least partly immaterial, that might give us a reason to suppose that we could survive disembodied. But suppose we don’t know that. Suppose that for all we know we are entirely material. Then for all we know we can’t survive disembodied. If there were material thinkers, they would have the same grounds for supposing that they could survive in a disembodied state as we have for supposing that we could; yet they would be mistaken. How can we be sure that we’re not mistaken in this way? Only by ruling out the possibility of our being material ourselves. But that is what we were trying to establish in the first place.
- As for the inadequacy-of-physicalism argument: it may well be that we cannot conceive how a material thing could produce thought or consciousness. But then we can no more conceive how an immaterial thing could produce thought or consciousness: no matter how carefully we reflect on the notion of an immaterial substance, we shall never find anything that could account for thought or consciousness. It is no easier to explain a thing’s ability to think on the hypothesis that it is immaterial than it is on the assumption that it is material (Taylor 1963: 25). And if an immaterial thing could produce thought in an ultimately mysterious and inexplicable way, why couldn’t a material thing produce thought in an ultimately mysterious and inexplicable way? There is of course more to be said about these arguments, both on the part of the prosecution and on the part of the defense; but not here. Let us turn to an altogether different sort of case for immaterialism.
7.4 The cost of materialism
- One obvious advantage of immaterialism is that it can solve the thinking-animal problem. It could hardly be the case that both immaterial human souls and human organisms think. If we thinkers are immaterial, human animals will lack any mental properties at all. At any rate they will be unable to think as we do. So if we were souls we could know that we are not thinking animals. For that matter, we could know that we are not thinking brains. Only one being would think your thoughts. Whether any other account of what we are2 has this advantage is contentious (see Chapter 9). Of course, immaterialists will still need to explain why human animals cannot think. But they will have resources for doing so that are unavailable to materialists. It is easier to explain why human animals cannot think on the hypothesis that no material thing could think than it is to explain why they can’t think even though other material things can think.
- Here is something different: a problem for almost any account of what we are3 save immaterialism4. If we were anything other than simple immaterial substances--if we were animals, or material things constituted by animals, or parts of animals, or bundles of mental states, for example--then we should have different parts at different times. We should sometimes grow by acquiring parts, and sometimes shrink by losing them. But there is a metaphysical obstacle in the way of a thing’s acquiring new parts.
- Suppose we have an object, A--anything at all--and we want to make it bigger by adding a part, B. That is, we want to bring it about that A first lacks and then has B as a part. Let us therefore conjoin B to A in some appropriate way. Never mind what this conjoining amounts to: let us do whatever it would take to make B a part of A if it can ever be. Have we thereby made B a part of A?
- It seems not. We seem only to have brought it about that B is attached to A, like this: Figure 7.1 We have rearranged A's surroundings by giving it a new neighbor, but we haven't given it a new part. If we have made B a part of anything, we have made it a part of the thing made up of A and B after our conjoining. But that thing didn't gain any new parts either. It didn't exist at all when we began. Our conjoining B to A brought it into existence. Or if it did exist at the outset, it already had B as a part then and we didn't make it any bigger, but merely changed it from a disconnected object (like an archipelago) to a connected one. It seems that nothing we can do would ever give A a new part. And because this reasoning makes no assumptions about the nature of A or B or the manner in which they are conjoined, it entails that nothing, including you or I, can grow by gaining new parts. This is the paradox of increase or growing argument.
- A similar argument appears to rule out a thing’s shrinking by losing parts. Suppose we want to make an object X smaller by removing a part, Y. That is, we want to bring it about that X first does and then doesn't have Y as a part. Let us therefore detach Y from X in some appropriate way: let us do whatever would bring it about that Y ceases to be a part of X if X can ever lose Y as a part and carry on without it. Have we thereby made it the case that X no longer has Y as a part? Have we made X smaller? It seems not. X starts out made up of Y and the rest of X--call the rest of X Z--like this: Figure 7.2 What happens to X when we detach Y? Apparently it ceases to exist. Or if it does still exist, it still has Y as a part, and we have merely changed it from a connected object to a scattered one. Either way, it doesn't shrink by losing a part. And of course Y and Z don't lose any parts either. It seems that nothing we can do would make anything smaller by removing one of its parts. Alert readers will recognize this as the amputation puzzle of §3.3. Like the growing argument, it assumes nothing about the nature of X or Y or the manner in which Y is detached. So it threatens to show that nothing could ever lose a part: the very idea of shrinking by losing parts is incoherent.
- If these arguments are sound, it is hard to see how anything could exchange an old part for a new one without shrinking or growing either. So they suggest the more general conclusion that nothing can have different parts at different times: it is absolutely impossible for anything to have a certain part at one time and exist without having that thing as a part at another time. This is the doctrine of mereological constancy. (It is not the same as mereological essentialism, the claim that nothing could exist without having just the parts it actually has. Mereological constancy does not entail mereological essentialism: the impossibility of my having a certain thing as a part at one time and lacking it at another would not rule out my existing without ever having it as a part. It might be possible for me to have had different parts all along, even I cannot change my parts.)
- The doctrine of mereological constancy is plainly trouble for anyone who takes us to be material things. For that matter, it would be trouble if nothing could grow by gaining parts, even if mereological constancy in its full generality were false; but it is simpler to put the argument in terms of mereological constancy. If you are a material thing, your atoms are constantly coming and going, owing to metabolic turnover. Mereological constancy implies that the atoms you assimilate do not become parts of you, and the atoms you expel do not cease to be parts of you. It follows that you are not the being who bore your name a moment ago, for you now have parts that were not then parts of that being. Nor are you the being who will answer to your name a moment hence, for that being will have parts then that are not now parts of you. What appears to be a persisting human being is in reality a series of numerically different beings, succeeding one another at a rate of trillions per second. You retain your human form for only a moment.
- What happens to you when your metabolism assimilates or expels an atom--supposing that you are a material thing? Mereological constancy by itself does not answer this question. It says only that you don’t gain or lose any parts. That doesn't tell us what happens to you because it doesn't say what it would be for you to gain or lose parts. Specifically, it doesn't tell us whether the atoms you shed thereby stop being parts of you, or whether the atoms your metabolism assimilates are parts of you before it assimilates them. And what happens to you when you expel an atom depends, among other things, on whether that atom continues to be a part of you when it no longer coheres with the rest of your atoms.
- Suppose first that it doesn’t. Then according to mereological constancy you--or perhaps we ought to say the being we now call you--exist only as long as all your current atoms stick together: not long at all. As soon as you shed an atom, you cease to exist and are instantly replaced by something new: something very like the human being who existed a moment earlier, but numerically different because it has different parts. You are what we might call a momentary mass of matter.
- Now suppose the opposite: that your atoms do remain parts of you when they disperse. In that case you presumably continue to exist for as long as your atoms exist, no matter how they come to be arranged. (If your atoms remain parts of you even when they are scattered to the four winds, it is hard to see what could cause them to cease to be parts of you, save destroying them.) So the being we now call you survives the expulsion of an atom, and merely changes thereby from a connected object to a disconnected one. Part of you remains in one piece; the rest of you disperses. In a few years’ time, when all your current atoms have been expelled, you will be scattered thinly across the biosphere. You were similarly scattered in the past. You have existed for billions of years, and will continue to exist until one of your atoms is destroyed. You have spent most of your career up to now as a nondescript and widely scattered cloud of cosmic dust. More recently you became confined to the earth, and a short time ago you began to coalesce into human form. But the moment you become fully human you immediately begin to disperse once more. In all likelihood your future holds nothing but eons of unremitting tedium. As in the first story (where you perish when you shed an atom), you are instantly replaced, when you cease to be human, by another human being. The difference is that on the second story the beings that successively bear your name exist before and after they take on human form, whereas on the first story they exist only for the brief moment when they are human. On this account you are what we might call a persisting mass of matter.
- Now these are, I suppose, possible views about what we are5. The momentary-mass view would be that each of us is a momentary mass of matter: a material thing that exists only as long as the atoms composing it remain stuck together. The persisting-mass view would be that each of us is a persisting mass of matter: a material thing that exists if and only if the atoms that compose it at any time exist. Either view would make it impossible to say which mass of matter you are. Presumably you would be a mass the size of a human being, rather than something larger or smaller. But a different mass would bear your name at every moment, and it would be entirely arbitrary to say that any one of them, rather than another, was you. In this respect both proposals resemble the stage view (§5.8).
- The view that we are masses of matter, whether momentary or persisting, can only be described as dreary. If that is what materialism comes to, so much the worse for it. It would be no help to suppose that we are bundles of mental states, for mental states come and go nearly as rapidly as atoms do. Given mereological constancy, the only account of what we are6 that is compatible with our having anything like the sort of careers we think we have--with our persisting as human thinkers for dozens of years--would seem to be immaterialism. So here is an argument for immaterialism: Nothing can have different parts at different times; but the only sensible account of what we are7 that is compatible with this is immaterialism; therefore we are immaterial substances.
- There are two broad ways of resisting this argument. One is to argue that we needn’t accept the doctrine of mereological constancy. That is, we might try to solve the paradox of increase and the amputation puzzle. The other is to propose a materialist account of what we are8 that is compatible with mereological constancy. The momentary- and persisting-mass views are examples of this, and in §7.7 we will consider two more. But let us first see what it would take to avoid mereological constancy.
7.5 Objections to immaterialism
- What would it take to solve the paradox of increase? Let us examine it more closely.
- The paradox purported to show that an object, A, can never acquire a new part, B. Well, suppose for the sake of argument that conjoining B to A in some appropriate way does make it a part of A. Suppose, that is, that A and B don’t come to make up some new thing, as Figure 7.1 invites us to think, but rather that A comes to be made up of B and something else. That something else may appear to be A itself: it is made of the same matter as A was a moment earlier (supposing that A is a material thing), and that matter continues to be arranged in just the same way. It differs from A as it was before only in its surroundings. This fact--that the thing B ends up attached to appears to be A--is what supports the claim that B never comes to be a part of A, thereby generating the paradox. But let us try to resist this thought. To avoid assuming the point at issue, call the thing that looks like A and ends up attached to B, C. Suppose, then, that when we conjoin B to A we make it a part of A, so that A comes to be made up of B and C: Figure 7.3
- Is there anything wrong with this? Well, where did C came from? Where was it before we attached B? Presumably it existed then: conjoining B to A didn’t bring C into being. If conjoining two objects adds anything to the furniture of the earth, it ought to be something made up of those two objects. We don’t expect conjoining B to A to create a new object that is now just like A was before the conjoining. We can make this more vivid by imagining the process in reverse: suppose A is made up of C and B and we want to make it smaller by removing B as a part. If attaching B to A brings C into being, then detaching B again ought to destroy C. But surely we can’t cause an object to cease to exist just by detaching from it an object that was never a part of it. We can’t destroy an object merely by changing its surroundings.
- Suppose, then, that C existed before B was attached. Presumably C was the same size as A was then: attaching B didn’t make C any bigger or smaller. A and C must have occupied exactly the same place before B was attached. So Figure 7.3 ought to show A and C superimposed on the left-hand side. But their relationship then is more intimate than mere colocation: they coincide materially. They are made of the same matter then, and share all their proper parts; or at least there are things that compose A, and also compose C, before B is attached.
- But it seems that two different things cannot coincide materially. The same parts cannot make up two different wholes at once. In that case C really is A, and our story has fallen apart. C wasn’t supposed to acquire B as a part: that was the whole point of bringing C into the story. But if C is A, then A didn’t acquire B as a part either, contradicting our original assumption that A did acquire B as a part. That assumption has therefore been reduced to absurdity.
- Let us make the argument’s premises explicit. First we supposed, for reductio, that conjoining B with A makes it a part of A:
1. A acquires B as a part. In that case, we reasoned, A comes to be composed of B and a third thing, “the rest of A apart from B”, which we called C:
2. When A acquires B as a part, A comes to be composed of B and C. Now obviously B doesn’t come to be a part of C when we attach it:
3. C does not acquire B as a part. And making B a part of A doesn’t appear to bring C into being; rather, C existed before we attached B to it:
4. C exists before B is attached. Nor did C get any bigger or smaller when we attached B: it had the same boundaries, before B was attached, as A had then. What’s more, there were things that composed A and also composed C then:
5. C coincides materially with A before B is attached. But
6. No two things can coincide materially at the same time. And 5 and 6 imply that But if C is A, and C doesn’t acquire B as a part (3), then neither does A:
8. A does not acquire B as a part, contrary to 1. The assumption that A gets bigger by gaining a part leads to a contradiction, and is therefore false. There are, as far as I can see, five possible ways of blocking this argument.
- One is to challenge its logic9. Someone might say that C and A are one thing before we attach B and two things afterwards. What start out as a thing and itself come to be a thing and another thing. Identity is time-relative: things might be identical at one time and distinct at another, just as you and I might be neighbors today and not neighbors tomorrow. So all that follows from 5 and 6 is that C is identical with A before B is attached, not that C is identical with A simpliciter. If C is not A after B is attached, then the fact that C doesn’t gain B as a part does not imply that A doesn’t gain B as a part, and the argument fails. This idea--call it the way of funny logic--is hard to take seriously. Suppose that C and A are one thing now but two things tomorrow. The suggestion is that tomorrow B will be a part of A and not a part of C. So A is about to get bigger, but C isn’t. That means that A now has a property that C now lacks, namely being such that it will have B as a part tomorrow. But C and A are now the very same thing. How can a thing now have a property that that very thing now lacks10? If the growing argument is logically impeccable, those who reject its conclusion will have to deny one of its premises.
- The first substantial premise is 2, that if A acquires B as a part, it comes to be composed of B and “the rest of A”, C. This assumption makes trouble because C appears to be identical with A; and since C doesn’t acquire B as a part, it follows that A doesn’t either. So we might deny that there is ever such a thing as C. Of course there is something in the box labelled ‘C’ in Figure 7.3. B is never A’s only part: there is another part of A that B ends up attached to. But there is no one such thing as “all of A apart from B”. There is no one thing whose boundaries the box represents. There are only a lot of smaller things--D, E, and F, say--each of which partly fills that space. We can illustrate this by re-drawing the picture so: Figure 7.4 before: after: A starts out composed of D, E, and F, and when it gains B as a part it comes to be composed of D, E, F, and B. But D, E, and F don’t themselves compose anything after B is attached: there is nothing that has D, E, and F as parts then, and every part of which then shares a part with D, E, or F. The proposal is not merely that D, E, and F don’t then compose anything interesting, or don’t compose a “genuine object” or the like. It has to be that they don’t then compose anything at all. Call this the way of sparse ontology.
- We can perhaps best see how surprising this proposal is by considering the corresponding solution to the amputation puzzle (van Inwagen 1981, Lowe 2002: 75-76). (If the way of sparse ontology is to provide a general solution to the paradox of increase, we should expect it to solve the amputation puzzle in a similar way.) That would be to deny that anything ever has a proper part that it could be pared down to. Assuming that you could survive the loss of your left hand, this implies that there is now no such thing as your left-hand complement--“all of you but your left hand”. Nothing wrong with that, you might think: hand complements would be arbitrary, gerrymandered objects, and there is little reason to believe that they exist. But it has worrying implications. For one thing, if there are no hand complements, there are unlikely to be any hands. What principled reason could there be to suppose that there are hands but no hand complements? Hands don’t seem to be ontologically special. More seriously, the way of sparse ontology implies that there is now no such thing as your head either--assuming that it is possible for you to survive, even briefly, being pared down to a head. That would demolish the ontology of “parts of the body” that we learned at nursery school--hardly a comforting thought.
- A third way of resisting the argument is to accept that C exists after B is attached, but deny that it exists beforehand (step 4). We could say, rather, that attaching B to A brings C into being. More generally, whenever any object gains a part, a new thing, composed of the object’s original parts, is thereby created. Suppose we have a house made of red Lego bricks, and we make it bigger by adding an extension made of blue Lego bricks. (If any material thing can grow by acquiring new parts, it ought to be possible for a house to do so.) When the original red house expands by acquiring blue parts, a new red house, composed of the original red bricks, immediately comes into being to take its place. Or perhaps we ought not to call the new object a house: maybe no proper part of a house can be a house itself. In any case, the building work creates a new material object very like a house.
- Applied to the amputation puzzle, the claim is that whenever anything loses a part, the complement of that part--the thing composed of all the object’s parts save those that overlap the lost part--ceases to exist. So there is now such a thing as your head, but cutting away the rest of you would necessarily destroy it: the head you would be in this radically maimed condition would not be the head you have now.
- Call this the way of funny persistence conditions (Burke 1994, 1996; Rea 2000). It is no easier to believe than the way of sparse ontology. When we lay bricks, we may expect to create a new object made up of those bricks. But the way of funny persistence conditions has the baffling implication that laying only blue bricks can bring into being an object made up entirely of red bricks. Likewise, we can destroy an object made entirely of red bricks by moving only blue bricks. This is not merely implausible, but arbitrary and unprincipled: it implies that things come into being and pass away in an apparently capricious and inexplicable way.
- The next questionable claim in the argument is 6, that no two things can coincide materially at once. As we saw in Chapter 3, constitutionalists say that different things can coincide materially at once. They will say that C is not identical with A; it begins, rather, by coinciding materially with A, and ends up as a part of A when A grows by assimilating B. Likewise, when an object shrinks by losing a part, it comes to coincide materially with the complement of that part--the largest part of the object that didn’t share a part, before the loss, with the lost part. Call this the way of coincidence.
- This may sound like a neat solution: simply drop the dogmatic assumption that no two things can be in the same place and made of the same matter at once. In fact some philosophers use the amputation case as an argument for constitutionalism (Thomson 1983). But if this solves the puzzle, it creates another: If A got bigger, why didn’t C get bigger too? If conjoining B to A makes it a part of A, why doesn’t conjoining it in the same way to C make it a part of C? Presumably it is no accident, according to the way of coincidence, that A acquires B as a part and C doesn’t: if we conjoined B a thousand times, it would come to be a part of A each time and would never become a part of C. A, but not C, has the capacity to grow by gaining B as a part. Presumably C cannot gain any parts at all. This is surprising. A and C are exactly alike before the attachment. They have the same parts then, arranged in the same way. They are physically identical. They have the same surroundings. They may even have the same past history. There is no difference between A and C that could account for their differing capacities to acquire parts. In any case, we saw earlier that constitutionalism faces all manner of problems.
- Finally there is the way of temporal parts (Heller 1984, Sider 2001: ch. 5). Suppose, to make things simple, that A’s acquiring B is the only change of parts in its career, and that B comes to an end when A does. Then A is composed of C and the largest temporal part of B located after it is attached. On this view our “before” and “after” pictures are misleading; it is better to use a spacetime diagram, where the vertical axis represents space, the horizontal axis represents time, and A is the shaded object: Figure 7.5.
- The way of temporal parts is hard to compare with the alternatives because it holds that things have their parts without temporal qualification. In stating the paradox we spoke of the parts a thing has at some time, much as we speak of how tall something is at some time. But according to the way of temporal parts things have their parts timelessly (§5.2). A thing may have parts that are located at different times, just as it may have parts located in different places, but those parts are parts of it simpliciter. Like the way of coincidence, the way of temporal parts rejects 6, the claim that no two things can coincide materially at a time. But because fourdimensionalists take parthood to be a timeless relation, they understand 6 differently from coincidentalists. On their view, for things to coincide at a time is simply for them to share those of their temporal parts that are located then. So as they see it, A coincides with C before B is attached only in the way that two roads may coincide for part of their length.
- Four-dimensionalists accept the atemporal analog of 6: that no two things can coincide materially simpliciter. A differs from C, on their view, in that A but not C has the later temporal parts of B as parts. This gives the way of temporal parts an advantage over the way of coincidence: it is not committed to the mysterious view that things can differ in their kind and their capacity to gain parts without differing in their internal structure or surroundings. But as we saw in chapter 5, the way of temporal parts is no less controversial than any other solution to the paradox.
- To my mind, none of these five ways offers a satisfying solution to the paradox of increase. It is far from clear whether any of them is better than the mereological ailment it is meant to cure. This might make the combination of mereological constancy and immaterialism look rather attractive.
- Whether this is a strong argument for immaterialism, though, is uncertain. Even if the argument for mereological constancy is sound, there is peril in inferring from this that we are immaterial. Consider those material objects that, according to mereological constancy, take on human form for a moment before either ceasing to exist (if they are momentary masses of matter) or gradually dispersing (if they are persisting masses). Each of those beings has, for a moment at least, a working human brain and nervous system. It is surrounded by a community of thinkers and speakers. It has the same evolutionary history as we have. That ought to suffice for it to have mental properties. It ought to be conscious and intelligent, just as we are, for as long as it remains human. The material thing that is now human and sitting in your chair ought to be a subject of your current thoughts and sensations: it ought to think what you now think and feel what you now feel.
- But if there are material beings thinking our thoughts, even if each one thinks for only a moment, there are unlikely to be immaterial beings thinking our thoughts as well. No one ever supposed that for each human person there is, at any moment, both an entirely material thing and an entirely immaterial thing, each bearing all the mental properties that person has then. And if there is no immaterial thing thinking your thoughts, then you are not an immaterial thing. (Surely you are not an unthinking immaterial thing.)
- Those who say that you and I are immaterial will want to deny that any material things think our thoughts. But the argument from mereological constancy, by itself anyway, gives no grounds for such a denial. The claim that material things have careers very different from the ones we thought they have looks consistent with their being able to think as we do while they are human. Put it this way: the argument from mereological constancy implies that we are either immaterial things or material things with alien careers. But it gives no reason for choosing the first alternative over the second. For that we should need a reason to suppose that the material things we should be if we were material at all would lack the mental properties that we have. But we appear to have no such reason.
- You might argue that nothing could think for only a trillionth of a second. That just isn’t long enough. Since no material thing would have more than a trillionth of a second to think if mereological constancy were true, it would follow that no material thing could think. This is certainly an argument worth considering. On the other hand, even if no isolated being that existed for only a trillionth of a second could think, maybe a thing could have a mental property for any length of time—even for an instant—if it has the right causal antecedents11. (Indeed, the ontology of temporal parts appears to be founded on this claim.) What it is right to say here, it seems to me, is anyone’s guess.
- The paradox of increase may not be a strong argument for immaterialism. But even if it isn’t, it looks like a powerful argument for some surprising claim. If nothing else, it shows how hard it is to be a materialist. Materialists will need to say something about it. We will return to this theme in Chapter 9.
7.6 Compound dualism
- Objections to immaterialism are all too familiar. Now I complained earlier that many common objections were over-hasty, owing to the perceived weakness of their target. But here are three serious worries. They are not strictly objections to immaterialism per se, but to substance dualism; but because few immaterialists want to accept idealism, we can see them as objections to most versions of immaterialism as well. (Nor is idealism entirely immune to them.) All have to do with the way the mental relates to the physical.
- If you step on a tack and cry out in pain, it seems plain enough that the damage to your foot causes your pain and that your pain causes your cry. If you are a soul, your pain is a state of that soul. One of the over-hasty objections claims that no non-physical state of an immaterial thing could possibly bring about, or be brought about by, physical events in a material thing. I find this objection dogmatic. We cannot predict a priori what can cause what, and no experience tells us that nothing non-physical can cause something physical. But we can sharpen the objection. We can ask, for instance, what it is about a given soul that enables it to interact in this way with a given organism. According to immaterialism damage to my animal body causes pain in my soul, and mental events in my soul cause my body to move. It is a striking fact that no other soul interacts with my body in this way, and that my soul never interacts in this way with any other organism. Why should this be? Kim (2001) calls this the pairing problem: what “pairs up” souls with bodies?
- We are unlikely to find an answer to this question in the intrinsic features of souls and bodies. It seems evident that I should not interact in this way with a duplicate of my body, nor would a duplicate of my soul interact in this way with my body. The same goes for material things. Why is it that turning this key opens that lock? It isn’t just the way the two objects are in themselves. Turning a key in Tasmania--even a key of just the right size and shape--won’t open a lock in Japan. For a key to open a lock, the key and the lock need to be in the same place. Perhaps that is how it is with souls and bodies: for a given soul to move a given body, they have to be in the same place. What prevents my soul from moving other bodies and other souls from moving my body might be that they are in different places12.
- But this suggestion is problematic. For one thing, if the soul interacts with the body, it interacts with different parts of the body, specifically different parts of the brain, at the same time: for instance, it receives visual information from the occipital lobe at the same time as it receives auditory information from the temporal lobe. (Descartes was wrong about the pineal gland.) If this interaction requires spatial co-location, then the soul needs to be at least as big as the brain, threatening the claim that it is simple and immaterial. More seriously, we should have to wonder what keeps my soul and my body in the same place. Substances that don’t share any parts ordinarily move independently. But if my ability to move and perceive requires my soul to be located where my body is, then wherever my body goes, my soul goes too: I never find myself suddenly unable to move or perceive because my body and my soul have got separated. What sort of psycho-physical glue averts this calamity?
- A second problem to do with soul-body interaction is what van Inwagen (2002b: 196-98) calls the remote-control argument. If it is souls that think, then they relate to their bodies in something like the way someone relates to a device she is operating by remote control--a robot, say, that not only moves according to her commands but also sends her sensory information about itself and its surroundings via headphones and a video screen. Now damage to such a robot might interfere with this exchange of information, so that the robot stops acting on the operator’s commands and stops sending her sensory information. That is, damage to the robot would affect the operator’s ability to interact with it. But it wouldn’t affect the operator directly in any other way. If this analogy is correct, then according to substance dualism we should expect a violent blow to the head to affect the soul's ability to interact with the body, perhaps rendering one unable to move or perceive anything--but it shouldn’t affect the soul directly in any other way. We should expect someone who is “knocked out” to remain conscious, and to be able to tell us afterwards what she was thinking while she was unable to move or perceive. Yet we know that this is not the case: a hard knock on the head causes complete unconsciousness. As long as we remain embodied, anyway, we cannot think or be conscious unless our brains are working. This is an awkward fact for the immaterialist. Why should damage to a material thing prevent something entirely immaterial from functioning?
- One might answer by denying that souls think. Rather, the soul might do something necessary but insufficient for thought: for thought to occur, the soul’s contribution must combine with some sort of activity on the part of the brain. All mental activity would consist of an immaterial ingredient in the soul and a material ingredient provided by the body. In that case damage to the brain could stop thought by removing the material ingredient. Whatever merits this proposal may have, however, it rules out immaterialism, for if souls don’t think our thoughts but something else does, then we are not souls. It suggests that we are things made up of both souls and bodies (or souls and brains)--a view we will take up in the next section13.
- Then there is the duplication problem (van Inwagen 2002b: 198-201). Imagine a machine capable of making a perfect physical duplicate of anything: an object indistinguishable from the original, right down to the subatomic level. What would happen if we put a human being into this machine--you, for instance? Well, we should get a perfect physical duplicate of you. What would it be like? Unless modern biochemistry is badly mistaken, it would be alive in the biological sense. But what mental properties would it have? Immaterialism suggests that it would have none at all. (Let us suppose that there is no miraculous divine intervention.) Because it would lack a soul, it would be a sort of human vegetable. At any rate it would lack those mental properties that only things with souls can have; and there is little point in believing in souls unless there are many such properties.
- Of course, we shall never be able to test this prediction experimentally. But it doesn’t sound right--not to most of us, anyway. It certainly isn’t what medical science leads us to expect. As far as we know--and neurologists have studied the matter extensively--every actual case in which a human animal has a serious cognitive deficiency over a long period is a case in which there is a serious physical defect in its brain. It would be astonishing if the animal produced by duplication, which would have a physically normal brain, had anything but normal mental capacities. If our expectations are correct and the duplicate would have normal mental capacities, though--if reproducing your physical states suffices to reproduce your mental states- -then we don’t think by virtue of having immaterial souls, contrary to immaterialism.
- Someone might try to solve this problem by saying that a brain brings a soul into existence when it is in the right state, much as a piece of steel in the right state produces a magnetic field (Hasker 1999: 190; 2001). Since your physical duplicate would have a brain just like yours, its brain would cause a soul to exist, just as your own brain causes your soul to exist. Given that like causes tend to have like effects, we should expect the new soul to resemble yours. This might help answer other hard questions too: for instance the question of when in the course of its development a human organism acquires a soul (and why then, rather than earlier or later). It may even help with the remote-control problem: perhaps a hard knock on the head causes the soul to go out of existence, much as heating a magnet and thus realigning its particles destroys its magnetic field. If the brain recovers sufficiently, it then generates a new soul (or perhaps the original soul comes back into being), and mental activity resumes. Advocates of this sort of view call it emergent dualism.
- Emergent dualism seems to me to face an awkward dilemma. We have been supposing that souls are immaterial substances. But it is hard to see how the physical activities of a biological organ could bring into existence an immaterial substance. That would be creation ex nihilo (the soul wouldn’t be forged out of previously existing materials). Of course, the mere fact that it is hard for us to see how one thing could bring about another may be a poor reason to suppose that it couldn’t happen. But it doesn’t help matters that there are no other uncontroversial cases in which a substance is created ex nihilo. The idea that brains produce immaterial substances also does nothing to solve the pairing problem.
- The emergence of souls out of brains would be less mysterious if souls were not substances but rather states or modes of the brain--like your fist or your lap, rather than like your hand. That is what the analogy of the magnetic field suggests: though the metaphysics of fields is poorly understood, they sound more like states--either of the objects generating them or of space (or spacetime) itself--than like substances. This would also help with the pairing problem: your soul could no more leave your brain behind than your lap could wander off without you. But the view that souls are states rather than substances is incompatible with our being immaterial substances--that is, with immaterialism. What are we14, then, if we think by virtue of having immaterial but insubstantial souls? If we are those souls, then we are something like collections of mental states: a version of the bundle view. If we are not souls, but rather the substances of which they are states, then we might be organisms, or brains, or material things constituted by organisms or brains.
- These worries would cause me a good deal of unease if I were an immaterialist.
- I turn now to three views that resemble immaterialism. The first says not that we are souls, but that we have them as proper parts. We are only partly immaterial: each of us is made up of both a simple immaterial substance and a material organism. Call this compound dualism. We can call the view that we are souls and that we have bodies that are not parts of us pure dualism. (Pure dualism differs from immaterialism by implying the existence of material things.)
- Those who speak of substance dualism more often state it as compound dualism than as pure dualism, and a least one prominent dualist is a compound dualist (Swinburne 1984: 27, 1997: 145). The attraction of compound dualism over pure dualism is presumably that it would give us the physical properties we ordinarily take ourselves to have. Pure dualism, like the bundle view, implies that we are not really visible or tangible. We don't literally grow larger in our youth or grey and wrinkly in old age. We are not even men or women: a man or a woman must surely be at least partly material. Only our bodies are visible or wrinkly or male or female, and they are not parts of us. Compound dualism, by contrast, implies that parts of us really are visible and tangible; and having a visible part seems to be a way of being visible. Despite this virtue, however, compound dualism has troubles that have nothing to do with worries about dualism generally, and which pure dualism avoids.
- To start with, compound dualism inherits the problems facing materialist accounts of what we are15. Consider, for example, the paradox of increase. Pure dualists can give a neat solution: simply accept that nothing can change its parts, and point out that this doesn’t affect us because we are simple. Compound dualists will have to choose from the messy solutions available to materialists, thus forfeiting what is to my mind the best reason for accepting dualism in the first place.
- Second, there is what we might call the thinking-soul problem. If our souls think, yet we are not our souls, then we are not the beings that think our thoughts. We merely have thinking parts. That might make it true to say, in the right context, that we think, just as it might be true to say in the right context that my house is made of glass owing to the fact that it has glass windows. But we shouldn’t be thinkers in the strictest sense. And the idea that strictly speaking we don’t think, but things other than us think our thoughts, is hard to warm to. For that matter, if I believe that I am the compound, doesn’t my soul believe that it is the compound? How do I know that I’m not making that mistake? What justifies my belief that I am the compound and not the soul? Compound dualists will also need to explain why intelligent, self-conscious souls don’t count as people.
- Of course, this sort of trouble is not unique to compound dualism: we saw in §5.9 that according to the temporal-parts view we think only in the sense of having temporal parts that think strictly speaking. But then the ontology of temporal parts has all sorts of repugnant consequences. Its advocates are willing to live with them for the sake of its theoretical benefits, such as the solution it offers to the paradox of increase. Whatever the merits of this trade-off may be, no one can say that compound dualism offers theoretical benefits comparable to those of four-dimensionalism.
- Here is a third problem for compound dualism. Suppose my body is destroyed at the end of Monday and that my soul continues to exist without a body on Tuesday. Compound dualism ought to allow for this: a substantial soul shouldn’t need a body in order to exist. Now if my soul could survive this, I could survive it. (That’s what compound dualists say.) But in what form should I survive? It seems that I should survive as a soul. There is nothing else there on Tuesday that I could be. But according to compound dualism I couldn't be my soul on Tuesday, for I was not my soul on Monday; and a thing cannot come to be identical with something that was previously only a proper part of it.
- Here is the problem laid out stepwise. Compound dualism implies that I could survive the destruction of my body at the end of Monday, so that
(1) The thing that is I on Monday is the thing that is I on Tuesday. In that case I should be identical with my soul on Tuesday:
(2) The thing that is I on Tuesday is the thing that is my soul on Tuesday. And we supposed that my soul survives the destruction of my body, so that
(3) The thing that is my soul on Tuesday is the thing that is my soul on Monday. From these three claims it follows by the transitivity of identity that
(4) The thing that is I on Monday is the thing that is my soul on Monday, which contradicts compound dualism. Call this the problem of disembodied survival. The obvious solution, for those who believe in disembodied survival, is to accept 4 and say that I was identical with my soul all along: that is, to adopt pure dualism.
- Now the problem of disembodied survival is a special case of the amputation puzzle. And we have already seen that compound dualists need to find a solution to that problem anyway. Can they not solve the problem of disembodied survival in the same way? Well, maybe they can. But it looks harder to solve the problem of disembodied survival than to solve the amputation puzzle generally. That is, even if we can explain how it is possible for a thing to survive the loss of some part, it looks harder to explain how a soul-body compound could survive the loss of its body. Obviously the way of sparse ontology won’t work, for that would mean denying the existence of embodied souls. The way of funny persistence conditions doesn’t look very nice either: it would mean that a person’s disembodied soul is not identical with the soul she had when she was embodied. No dualist would accept that.
- What about the way of constitution? Perhaps when I lose my body, my soul comes to constitute me, in the way that a lump of clay constitutes a clay statue. In that case I don’t come to be my soul when my body is destroyed, contrary to 2. But what would it mean to say that my soul constitutes me? The things philosophers typically say about the constitution relation don’t apply in the case of souls and people. For instance, it seems to belong to the idea of constitution that when one thing constitutes another they must be made of the same stuff or composed of the same proper parts. They have to coincide in some sense. The idea that disembodied souls constitute people numerically different from them therefore seems to require souls to have parts, or to be made of some sort of immaterial stuff. Most dualists reject that.
- Moreover, all constitutionalists accept three principles. First, a constituting thing can outlive the thing it constitutes: squash a clay statue and you destroy it, but the lump of clay that constituted it will still exist. Second, a constituting thing can constitute different things at different times: if we squash a statue of Thatcher and model the clay into the shape of Pinochet, the lump will constitute first one statue and then another. Third, a constituted thing can be constituted by different things at different times: by partial replacement of its matter, a statue constituted by one lump today can come to be constituted by another lump tomorrow. Now if your disembodied soul could constitute you, the first principle implies that your soul could outlive you: the survival of your soul is not enough for you to survive. The second principle implies that what is now your soul might one day come to be someone else's soul. The third implies that you could have different souls at different times. Compound dualists are unlikely to accept these claims.
- A fourth principle that constitutionalists generally accept is that whatever is constituted by something at one time must be constituted by something or other whenever it exists. If your soul constitutes you when you are disembodied, this implies that something must constitute you when you are embodied as well. It will presumably have to be something composed of your soul and your body: otherwise you and it would not in any sense coincide. (Remember that constitution, in the sense that is relevant here, is by definition a one-one relation: your soul and your body could not jointly constitute you.) So there would have to be two things now made up of your soul and your body: you, and the thing that now constitutes you. But only one of them would be able to survive disembodied16.
- These objections suggest that compound dualism is more interesting than it is attractive. If I were a dualist, I would be a pure dualist.
7.8 Simple materialism
- The idea that we are each composed of an immaterial soul and a material body might call to mind the Aristotelian view that we are compounds of form and matter. The idea is something like this: a human person, or indeed any material thing, comes into being when a certain human form or configuration is imposed on some matter. That form is not a universal--it is not the human form that all human people share--but rather a particular state that configures a particular batch of matter. The state that configures your matter comes into being when you do, namely when your matter first takes on your particular human form; and it is located where you are. You are in some sense made up, at a given time, of your human form and the matter that the form configures at that time. Or rather you are made up of those things and also various accidental forms, such as your mass and posture. Your accidental forms are only contingently parts or constituents of you, but your human form is an essential part: you couldn’t exist without having it as a part, nor could it exist without being a part of you. It determines what you most fundamentally are. Because of this it is called your substantial form.
- Aristotle called the substantial form of a living thing a soul; let us call it a hylomorphic soul in order to distinguish it from the Cartesian or Platonic soul that figures in immaterialism. A hylomorphic soul is not a substance, but rather a sort of state: the substance is what you get when a soul configures some matter. That is what distinguishes this proposal from compound dualism. Call the view that each of us is made up (at any given time) of a hylomorphic soul and some matter hylomorphism. I have serious misgivings about discussing hylomorphism.
- I don’t properly understand the view. It is true that I have discussed a number of views that I understand no better: the universal bundle view and the program view, for instance. I was happy to give my opinion about those views because I don’t think anyone properly understands them. But there are people who at least appear to have a profound understanding of hylomorphism, and they will no doubt find my remarks amateurish. Because they take hylomorphism to be an important account of our metaphysical nature, however, I feel I ought to say something.
- Hylomorphism is not a version of immaterialism. It says that we are material things. In fact all versions of hylomorphism that I know of say that we are biological organisms; so hylomorphism is strictly speaking a version of animalism. And hylomorphism as I have stated it appears to be compatible with everything I said about animalism in Chapter 2. However, some versions of hylomorphism diverge considerably from what I said there, and these differences might appear to make it more attractive than “ordinary” animalism.
- Someone might claim that hylomorphism combines the virtues of animalism with those of the constitution view. It implies that we are animals, just as we appear to be, and thus avoids the thinking-animal problem. More generally, it doesn’t make the troublesome claim that the same matter can make up qualitatively different things at the same time. On the other hand, it may avoid the traditional objections to animalism having to do with our identity over time. Suppose your cerebrum is transplanted into another head. Many people want to say that you would go along with that organ. Yet the human organism appears to stay behind with an empty head. If you are an organism, it follows that you stay behind with an empty head in the transplant case, which many people take to be absurd. Hylomorphists might be able to avoid this consequence without denying that we are animals. That is, they might be able to say that the human organism goes along with its transplanted cerebrum. How? Well, your soul--the configurational state that makes you what you most fundamentally are--is a rational soul. It is what gives you the capacity for rational thought. And your capacity for rational thought goes along with your cerebrum in the transplant case, rather than staying behind. Your hylomorphic soul therefore goes along with your transplanted cerebrum. And where your soul goes, you go. Thus, transplanting your cerebrum transplants you. It doesn’t move you from one animal to another; rather, it moves an animal from one batch of matter to another. In a similar way, hylomorphists might argue that each human animal is essentially rational, which ordinary animalism denies.
- Hylomorphists might say this, though it is not clear whether their hylomorphism demands it. (One of the reasons why I don’t understand hylomorphism is that I can’t work out what follows from it.) Should they say it? Should anyone say it?
- I myself find it deeply implausible. Forget about personal identity for a moment and think about biological organisms. Not even the hylomorphist will suppose that there are two human animals located where you are before the transplant. (That would be a version of constitutionalism, or perhaps four-dimensionalism.) So the view that a human animal goes along with its transplanted cerebrum implies that the animal left behind with an empty head (which may be alive and breathing on its own--the cerebrum plays no role in the regulation of life-sustaining functions) is not the animal that was previously whole. It is a brand-new human animal. At any rate it is biologically human. Hylomorphists may say that because it lacks the capacity for rational thought it is not human in the fullest sense. But never mind what sort of animal it is; the point is that according to the hylomorphist proposal you can bring a good-sized primate into existence by surgically removing someone’s cerebrum. That sounds wrong. Isn’t the result of removing an animal’s cerebrum simply that the animal loses an important organ? Couldn’t an animal--even a human animal--lose its cerebrum and continue living in a debilitated condition, just as it might lose a liver and continue living in a debilitated condition? The hylomorphist proposal says no.
- Or consider the empty-headed organism into which your cerebrum is implanted. What happens to it when the transplant is carried out? Doesn’t it acquire a new organ, much as an animal without a liver might acquire one? Not according to the hylomorphist story: when your cerebrum gets put into that animal’s head, the animal must cease to exist. Otherwise there would be two human animals in the same place at once--the one that lately had an empty head and the one that got transplanted--which is absurd. But implanting a cerebrum into an empty cranium doesn’t seem to be a way of destroying an animal. It seems, rather, to be a way of giving an animal a new organ. (We can see that this proposal commits its adherents to something like the way of funny persistence conditions of §7.4.)
- Now think of the animal that is supposed to move from one head to another. It would cease to be a living organism when it is removed from its head: a detached cerebrum is no more an organism than a severed arm is an organism. So the story implies that the animal ceases to be an organism while it is being transplanted and becomes a mere organ, and later becomes an organism once more. Being an organism is only a temporary and contingent property of organisms.
- It seems to me that there are two organisms in the story, and that one of them gives the other one an organ. But according to the hylomorphist proposal there are three: one that comes into being when the cerebrum is removed, one that ceases to be when the cerebrum is placed in the new cranium, and one that moves from one cranium to another. Hylomorphists will say that there are three organisms in the story because there are three different substantial forms: one rational soul, which moves from one head to another, and two nutritive souls, one of which configures the brainless matter left over after the cerebrum’s removal, and one of which informs the brainless matter that receives that transplanted organ. But this explanation doesn’t seem to make the proposal any more plausible.
- To my mind, the divergence of hylomorphism from ordinary animalism makes it less plausible than ordinary animalism, not more. An even more radical departure from ordinary animalism is Thomistic hylomorphism. It says that your hylomorphic soul can continue to exist after your death, when it no longer configures any matter. Not that it comes to configure some sort of immaterial stuff: it exists in a disembodied state as pure form. The soul can even engage in mental activity while it is disembodied: it can think and remember and be happy or sad (though it cannot, for lack of the relevant physical organs, perceive or act bodily). Some Thomists say that you can exist in this disembodied state; others say that you cease to exist when your soul becomes disembodied, but come back into being if your soul once again comes to configure some matter.
- When I try to think about Thomistic hylomorphism I see nothing but problems. Most obviously, I cannot see how a thing’s substantial form could continue to exist without being the form of anything, other than itself. Remember, a hylomorphic soul is neither a substance nor a universal, but a particular configurational state of a substance. Your hylomorphic soul stands to you as a dent stands to a dented car, or a knot stands to a knotted rope. The claim that a human being’s form could continue to exist after the human being is burned to ashes is like the claim that a knot could continue to exist after the rope it was in is burned to ashes.
- Thomists will want to say that the human soul is different from such states as dents and knots, and that this difference explains how the human soul can exist disembodied. It may be, for instance, that the human soul is not a physical or material state like a knot: you can explain what it is for a thing to be knotted in physical terms, but not what it is for a thing to be rational. But even if that is true, it doesn’t seem to help: a non-physical state that is not a state of anything is no less mysterious than a physical state that is not a state of anything.
- Nor do I see how a state, disembodied or otherwise, could think. That is like saying that thoughts think or dreams dream. This was one of the main objections to the bundle view. It appears to be an objection to Thomistic hylomorphism as well.
- Now consider the relation between yourself--the person or organism--and your soul. Suppose you could continue to exist in an immaterial state when your soul becomes disembodied. If it is hard to understand how an organism could persist without being an organism, that is nothing compared to understanding how an organism could persist without being a material thing at all. Thomists may say that you would no longer be an organism if you were disembodied; but that hardly helps. The trouble is not how something could be at once immaterial and an organism, but how something that is a biological organism at one time could be entirely immaterial at another time.
- And how would you relate to your disembodied soul? You couldn’t be your soul when it is disembodied, for you were not your soul when it was embodied. Yet there is nothing else, after your matter is dispersed or destroyed, that you could be. This is the same problem of disembodied survival that afflicts compound dualism.
- What if you couldn’t persist in a disembodied state, and would cease to exist, at least temporarily, if your soul became disembodied? That would mean that psychological continuity was not sufficient for you to persist: here would be a case in which your soul is uniquely psychologically continuous with you as you were when you existed, yet without being you. This is precisely the objection most commonly made against ordinary animalism, and which hylomorphism was supposed to avoid. Someone who says that you could be outlived by your thinking soul can hardly object to ordinary animalism’s implication that you might perish even though someone has your intact cerebrum.
- More seriously, if your soul can think when it is disembodied, why can it not think when it is embodied? If it does think when it is embodied, yet isn’t you, then you are not the being that now thinks your thoughts, but merely something that has that thinker as a part. Thomists would then face the same thinking-soul problem as compound dualists face. The obvious way to avoid the problem would be to say that we are souls. That would be a version of the bundle view. But it would not be hylomorphism.
- Thomistic hylomorphism seems to me to combine the problems of the bundle view with those of compound dualism. Thomists have attempted to reply to these objections, but the replies I have seen do not seem to me to answer them. The reason may be that I have not understood the replies. Or it may be that the Thomists have not understood the objections. Or perhaps I have misunderstood Thomistic hylomorphism in the first place. I don’t know. I will say no more about hylomorphism.
- We have considered the view that we are simple immaterial things and the view that we are each composed of a simple immaterial thing and a biological organism. What about the view that we are simple material things? Though this thought lies far off the beaten track, two important figures have defended it.
- Chisholm (1989) once argued that we are tiny physical particles. Although he didn’t say that these particles must be simple, his reasoning suggests that they would have to be17. More precisely, he reasoned that we must be tiny particles if we are material things at all. He argued for this in much the way that I argued for immaterialism in earlier sections: If we were material things, we should be either our bodies or parts of our bodies. But there are really no such things as our bodies, for they would change their parts, and nothing can change its parts. So we cannot be our bodies. We must therefore be parts of our bodies--in particular, parts of our bodies that never gain or lose any parts themselves. Chisholm suggested that each of us is a tiny particle within the brain. Call this view Lilliputian materialism.
- Why suppose that we are simple material things, rather than immaterial ones? Chisholm would probably turn the question around: why suppose that we are immaterial? Once we have accepted that we are simple, what do we gain by taking ourselves to be immaterial as well? What can an immaterial thing do that a material thing can’t? As we noted earlier, it is no easier to understand how an immaterial thing could think than it is to understand how a material thing could think. And supposing that we are immaterial makes trouble that materialism avoids: recall the pairing problem, the remote-control argument, and the duplication problem of §7.5. Lilliputian materialism is designed to avoid both the problems of materialism--the paradox of increase, for instance--and the problems of immaterialism.
- Here is an obvious objection: If we are material things, our thought arises in our brains. But a tiny physical particle hasn’t got a brain; and surely a material thing needs something like a brain to think. Chisholm replies that the tiny particle that you are has got a brain, even though its brain isn’t a part of it. Your brain needn’t be a part of you in order for you to use it to think. "The brain", says Chisholm, "is the organ of consciousness, not the subject of consciousness" (1989: 126).
- A more serious worry is this. There are many particles in the brain. Why is only one of them the subject of the mental states realized there? If a particle within the brain really could use the brain to think, why don’t they all think? And if only one particle thinks, what determines which one it is? Come to that, why must the thinking particle be located within the brain at all?
- The only answer I can think of to these questions is that the particles in the brain are not all equal. One of them is special: it directs the brain’s activities in something like the way that a conductor directs an orchestra. That is why it thinks and no other particle does. If it were removed from the brain, the brain would stop working as it ordinarily does, and the organism would show all the signs of complete unconsciousness--at any rate until some other particle takes over the directing role. Mysterious though the brain’s workings may be, however, I take it that neuroscience has pretty well ruled this out.
- Lowe has also argued that we are simple material things, or at least simple things with physical properties. His view is not that we are tiny particles, however, but that we have the size, shape, and weight that we think we have: we are six-foot, 150-pound mereological atoms (Lowe 1996: 36, 2000: 15-20, 2001: 151-154). We can get bigger or smaller without gaining or losing any parts. Call this Brobdingnagian atomism.
- This remarkable view contradicts the widely held principle that every extended thing must have proper parts--a north half and a south half, for instance--even if they cannot be separated. I hesitate to endorse this principle. But Brobdingnagian atomism also conflicts with the more compelling claim that internally heterogeneous objects must have parts. Something that is internally heterogeneous has different properties in different places: it might be red in one place, for instance, and not red in another. And nothing can be both red and not red. At most a thing might be partly red and partly not red. But what could it be for a thing to be partly red and partly not red, if not for it to have parts that are red and other parts that are not red? And of course if we are as big as we appear to be, we are internally heterogeneous: you yourself might be partly red and partly not red. It seems, therefore, that you must have parts.
- Not everyone agrees that internally heterogeneous objects must have parts. Spinoza thought that the cosmos had no parts, despite being as heterogeneous as can be. Spinoza and Lowe don’t say how a thing can be red in one place and not red in another without having any proper parts. One thing they might say, though, is that things in space have properties relative to places, just as things in time have properties relative to times18. For an ordinary thing to be red, it seems, is for it to be red at some time. And many philosophers believe that a thing can be red at a time without having a temporal part located exactly at that time that is red without temporal qualification. (Four-dimensionalists disagree: see §5.2.) Analogously, Lowe might say that a thing can be red in a place without having a spatial part located exactly in that place that is red without spatial qualification. For a thing to be red would be for it to be red at a place as well as a time (or at a spacetime location): here now, or in Chicago in 1975, or at every place and time where it exists. In that case things could vary across space without having spatial parts, just as things can change over time without having temporal parts.
- It is hard to know what to make of all this. If nothing else, it ought to lead us to wonder whether anything has parts. Take living organisms. Surely they have parts--vast numbers of them. (Lowe agrees. Although Brobdingnagian atomism is at least formally compatible with our being organisms, Lowe says that we are not our animal bodies, but merely coincide in some way with them.) But if the particles within your boundaries are not parts of you, and your vastly complex internal structure is compatible with your having no parts whatever, what reason could we have for supposing that organisms have parts? To put it the other way round, isn’t any reason to suppose that organisms have parts equally a reason to suppose that we have parts--supposing we have the physical properties of organisms? It is tempting to consider this a reductio ad absurdum of Brobdingnagian atomism.
- In any case, Lowe has an argument for the claim that we are simple (Lowe 1991: 88-89, Lowe 2001). Although it does not imply that we are simple material things, it is interesting in its own right. The idea is roughly this: if I had proper parts, I should have the same parts as my body. That would make me identical with my body. But I am not identical with my body. Therefore I have no proper parts. The main premises of the argument are these (where ‘part’ means proper part):
1. I am not my body (though both my body and I exist). Suppose I had parts. Then those parts would have to be parts of my body as well (by 3). Moreover, they would have to be all my body’s parts: if my parts were only some of my body's parts, that would make me a part of my body, which (by 2) I am not. So if I had any parts, they would all be parts of my body, and all of my body's parts would be parts of me. In that case I should be my body (by 4), which I am not (1). So I have no parts.
2. I am not a part of my body.
3. I have no parts that are not parts of my body.
4. No two things can have all the same parts.
- The premises of this argument are all attractive, and although the conclusion doesn’t strictly follow, the further premises needed to make it formally valid are relatively uncontroversial. I suppose it might provide some reason to suppose that we are simple. But it is unlikely to make many converts, for the allure of its premises is more than matched by the repugnance of its conclusion. If we are to come to believe that despite appearances we have no parts, we are going to need more than just a valid argument from attractive premises. We are going to need an argument that makes it seriously uncomfortable to believe that we have parts.
- As far as I can see, Lowe’s argument fails to do this. It does nothing to undermine the principal alternatives to its conclusion, for its premises amount to little more than bald denials of those alternatives. Premise 1 denies, in effect, that we are animals. (That is how Lowe understands it.) Premise 2 denies that we are spatial or temporal parts of animals. Premise 3 is inconsistent with most versions of the bundle view: if we are bundles of mental states, those states are unlikely to be parts of our bodies. (Bundlers who think the mental states composing us are parts of our bodies will probably deny 2.) And most advocates of the constitution view deny 4: they say that we have the same proper parts as human animals, even though we are not those animals. So Lowe’s argument will not trouble anyone who accepts one of these alternative views. Nor will it help those who are undecided about what we are19. Imagine someone wondering, "What am I20? A simple substance? An organism? A part of an organism, or something constituted by an organism? Or maybe a bundle of perceptions?" Such an inquirer would find Lowe's argument of little help, for in order to accept its premises she would have to rule out the main alternatives to our being simple things in advance. That is, she would have to believe, on grounds independent of Lowe’s argument, that we are not animals, or parts of animals, or bundles of perceptions, or things constituted by animals. The argument appears to be aimed at those who are inclined to accept its premises but who deny its conclusion. It is hard to think of anyone who fits that description.
Footnote 1: The divisibility argument appears in Descartes’ Sixth Meditation; for an interesting variant see Swinburne 1984: 14-21. For the argument from disembodied survival, see Swinburne 1984: 29-30 and 1997: 322-332. The classic statement of the inadequacy-of-physicalism argument is §17 of Leibniz’s Monadology; a good contemporary defense of it is Foster 2001: 25-28. §8.4 considers two further traditional arguments that would support immaterialism.
Footnote 4: The argument below is derived from Chisholm (1976: 89-113, 145-158). Zimmerman (2003) offers a complex argument a bit like this one for the same conclusion. Another important argument for immaterialism, so new I haven’t had time to consider it, is in Unger 2006: ch. 7. This section and the next are based on Olson 2006b.
Footnote 9: In the book, this is relegated to a footnote, with a reference to Olson 2006b.
Footnote 10: Funny logicians have an answer to this objection, but it does not seem to me to blunt its force. For more on the way of funny logic see Myro 1986 and Gallois 1990, 1998; Sider 2001: 165-76 is a helpful critical discussion.
Footnote 11: See §5.4. Shoemaker’s argument for the claim that no organism could think (§2.5) would also entail that no mass of matter could think, and his case against thinking masses might be stronger than his case against thinking animals. I doubt, though, whether it is compatible with our being immaterial substances (Olson 2002b; see also Shoemaker 2004). Immaterialists could also explain why there are no thinking material things by denying the existence of composite objects, thus combining mereological constancy with an extreme version of the way of sparse ontology.
Footnote 12: Foster (1991: 163-72) proposes a different solution, too complex to summarize here. Another important discussion of these matters is Shoemaker 1977.
Footnote 13: The question of why damage to the body renders the soul unable to think will be even more worrying for idealistic immaterialists than it is for dualistic immaterialists. For a different proposed solution to the remote-control argument see Robinson 1989: 49.
Footnote 16: I owe this point to David Hershenov. I say more about compound dualism in Olson 2001, where I probably treat it a bit too harshly.
Footnote 17: Quinn (1997), who discusses a different Chisholmian argument for the same conclusion, says explicitly that we are simple material objects.
Footnote 18: Hudson (2001: ch. 2) argues for a special instance of this view, namely that things have parts relative to places.
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