Patrick Toner takes an animalist line on human persons. Animalism is the doctrine that each of us is identical to an animal organism. A bit more precisely, "Animalism involves two claims: (1) we are human persons and (2) human persons are identical with animals." (67)
Let's consider the second claim. Toner endorses Eric Olson's 'thinking animal' argument for (2). Based on Toner's summary, I take the argument to go as follows. I am now sitting in a chair thinking a thought T. There is also now an animal sitting in this very chair and occupying the same space. Is the animal also thinking T? There are four possibilities.
a. I am identical to the animal occupying my chair, and the thinker of my thoughts is identical to this animal.
b. I am not identical to the animal occupying my chair, but I share the space with an animal that thinks all my thoughts.
c. I am not identical to the animal occupying my chair, but I share the space with a nonthinking animal.
d. There is no animal in my chair; hence I am not not identical to it.
Of the four possibilities, Toner considers (a) to be actual. "It's the least ugly of the choices. Indeed, it's positively common-sensical, compared with the other rather nutty options." (70)
I agree that (b) and (d) can be excluded right away. But I don't see that (c) is 'nutty' and I don't see that (a) is "positively common-sensical." Common sense has nothing to say about abstruse metaphysical topics such as this one.
The Corpse Objection to Animalism
On (a), the thinker of my thoughts is numerically identical to this living human organsm with which I am intimately associated. But If I am (identically) my body, then me and my body ought to have the same persistence conditions. But they don't: when I die I will cease to exist, but (most likely) a corpse will remain. Now if a = b, then there is no time t at which a exists but b does not exist, and vice versa. So if there are times when I do not exist but my body does exist, then I cannot be identical to my body. On (a), I will not survive death, but my body will: it will survive as a corpse. Therefore I am not identical to my body.
Toner's Response to the Corpse Objection
The Corpse Objection, in a nutshell, is that I cannot be identical to my animal body because it will survive me. My body exists now before my death and it will exist then after my death. It is the same body dead or alive. Toner's response is a flat denial of survival. My body will not survive me. Death is a substantial, as opposed to an accidental, change. When I die the animal body that I am will cease to exist and one or more new bodies will begin to exist. So it is not as if one bodily substance undergoes an accidental change, going from being alive to being dead; one bodily substance ceases to exist and one or more others begin to exist. The change is not alterational but existential. This implies that the body itself did not exist while the animal was alive. As Toner puts it:
Neither the body itself, nor any of its atomic parts, existed while the animal was alive. This just follows from the account of substance I've given, according to which substances have no substances as parts, -- there is only one substance here in my boundaries, and it's an animal. When the animal dies, whatever is left over is not the same thing that was there before. (71)
1. One question is whether, assuming that I am just this living animal body, my dying is an accidental change or a substantial change. I will suggest that it is more plausible to think of it as an accidental change.
If my dying is an accidental change, then something that exists now in one form will exist post mortem in a different form. This something could be called the proximate matter of my body. This matter is organized in a certain way and its organs and various subsystems are functioning in such a way that the entire bodily system has the property of being alive. (For example, the lungs are oxygenating the blood, the heart is pumping the blood to the brain, the pathways to the brain are unobstructed, etc.) But then suppose I drown or have a massive heart attack or a massive stroke. The body then ceases to have the property of being alive. On this way of looking at things, one and the same body can exist in two states, alive and dead. There is diachronic continuity between the living and dead bodies, and that continuity is grounded in the proximate matter of the body.
If, on the other hand, my dying is a substantial change, and I am just this living body, then at death I cease to exist entirely, and what is left over, my corpse, is something entirely new, 'an addition to being' so to speak. I cease to exist, and a corpse comes to exist. But then the only diachronic continuity as between the live body and the corpse is prime (not proximate) matter.
But what makes the corpse that comes to exist my corpse? Suppose I am just a living animal and that I die at t1. A moment later, at t2, two corpses come into existence. Which one do you bury under the 'BV' tombstone? Which is the right one, and what makes it the right one? Or suppose Peter and I die at the same instant, in the same place, and that dying is a substantial change. Peter and I cease to exist and two corpses C1 and C2 come into existence. Which is my corpse and which is Peter's? Practically, there is no problem: we look different and our looking different and having different dimensions, etc. is due to our different proximate matter, matter that is the same under two different and successive forms.
What this suggests is that dying is an accidental change, not a substantial change. It is an accidental change in the proximate matter of a human body. But if so, then the Corpse Objection holds and animalism is untenable.
There is also the very serious problem that substantial change requires prime matter, and prime matter is a very questionable posit. But I won't pursue this topic at present.
2. My second main question concerns how animalism is compatible with such phenomena as the unity of consciousness and intentionality. On animalism I am just a living human animal. The thinker of my thoughts is this hairy critter occupying my blogging chair. Is it the whole of me that is the res cogitans? Or only a proper part of me? Presumably the latter. If an animal thinks, then presumably it thinks in virtue of its brain thinking.
The animalist thus seems committed to the claim that the res cogitans, that which thinks my thoughts, is a hunk of living intracranial meat. But it is not so easy to understand how meat could mean. What a marvellous metabasis eis allo genos whereby meat gives rise to meaning, understanding, intentionality! It is so marvellous that it is inconceivable. My thinkings are of or about this or that, and in some cases they are of or about items that do not exist. I can think about Venus the planet and Venus the goddess and I can think about Vulcan even though there is no such planet. How can a meat state possess that object-directedness we call intentionality? Brains states are physical states, and our understanding of physical states is from physics; but the conceptuality of physics offers us no way of understanding the intentionality of thought.
And then there is the unity of consciousness. Can animalism account for it? At Plato's Theaetetus 184c, Socrates puts the following question to Theaetetus: ". . . which is more correct — to say that we see or hear with the eyes and with the ears, or through the eyes and through the ears?" Theatetus obligingly responds with through rather than with. Socrates approves of this response:
Yes, my boy, for no one can suppose that in each of us, as in a sort of Trojan horse, there are perched a number of unconnected senses which do not all meet in some one nature, the mind, or whatever we please to call it, of which they are the instruments, and with which through them we perceive the objects of sense. (Emphasis added, tr. Benjamin Jowett)
The issue here is the unity of consciousness in the synthesis of a manifold of sensory data. Long before Kant, and long before Leibniz, Plato was well aware of the problem of the unity of consciousness. (It is not for nothing that A. N. Whitehead described Western philosophy as a series of footnotes to Plato.)
Sitting before a fire, I see the flames, feel the heat, smell the smoke, and hear the crackling of the logs. The sensory data are unified in one consciousness of a selfsame object. This unification does not take place in the eyes or in the ears or in the nostrils or in any other sense organ, and to say that it takes place in the brain is not a good answer. For the brain is a partite physical thing extended in space. If the unity of consciousness is identified with a portion of the brain, then the unity is destroyed. For no matter how small the portion of the brain, it has proper parts external to each other. Every portion of the brain, no matter how small, is a complex entity. But consciousness in the synthesis of a manifold is a simple unity. Hence the unity of consciousness cannot be understood along materialist lines.
I tentatively conclude that option (c) above -- I am not identical to the animal occupying my chair, but I share the space with a nonthinking animal -- is, if not preferable to Toner's preferred option, at least as good as it, and not at all "nutty.' The Corpse Objection to Animalism seems like a good one, and Toner's response to it is not compelling, involving as it does the idea that dying is a substantial change, a response that brings with it all the apories surrounding substance and prime matter. Finally, it is not clear to me how animalism can accommodate intentionality and the unity of consciousness.
But perhaps Professor Toner can help me understand this better.