Persons and Bodies develops and defends an account of persons and of the relation between human persons and their bodies. According to the Constitution View of human persons, as I call it, a human person is a person in virtue of having a first-person perspective, and is a human person in virtue of being constituted by a human body (or human animal).
Thus, the Constitution View aims to give our animal natures their due, while recognizing what makes human persons ontologically distinctive. The Constitution View contrasts with two other leading accounts of human persons: Animalism and Immaterialism. Like Animalism but unlike Immaterialism, the Constitution View holds that human persons are material beings; like Immaterialism but unlike Animalism, the Constitution View holds that we are not identical to the animals that constitute us. of course involve self-reference, but it is self-reference of a distinctive kind.
On the one hand, human persons are constituted by human animals, and hence cannot escape their animal natures; on the other hand, there is more to human persons than their animal natures. What sets human persons apart from other animals has nothing to do with anything immaterial; rather what sets us apart is the ability that underlies our asking, “What am I?” That ability is a first-person perspective. First-person perspectives may well be the result of natural selection; but what is relevant here is not where they came from, but what they are and the difference that they make in what there is.
So, there are two theoretical ideas needed for the Constitution View of human persons: the idea of a first-person perspective, the property in virtue of which a being (human or not) is a person, and the idea of constitution, the relation between a human person and her body.
Part I, “The Metaphysical Background” (Chapters 1-3), explores and defends the two theoretical ideas. Part II, “The Constitution View Explained” (Chapters 4-6), uses these two ideas to give an account of human persons. Part III, “The Constitution View Defended” (Chapters 7-9), argues for the coherence of the general idea of constitution-without-identity and the coherence of the application of that idea to the notion of human persons; finally, it argues directly for the Constitution View by contrasting it with its competitors, Animalism and Immaterialism. Now turn to Persons and Bodies in greater detail.
Chapter 1 sets out the task. Persons and Bodies will answer three questions: What I am most fundamentally? What is a person? How are human persons related to their bodies?
Chapter 2 provides a technical account of the idea of constitution. The basic idea of constitution is this: when certain kinds of things are in certain kinds of circumstances, things of new kinds, with new kinds of causal powers, come into existence. For example, when a certain combination of chemicals is in a certain environments, a thing of a new kind—an organism—comes into existence. A world without organisms, even if it contained the “right” combination of chemicals but in the “wrong” environment, would not have the same things in it as a world with organisms. So, constitution makes an ontological difference. It guarantees ontological plurality.
The relationship of constitution is ubiquitous. It is not peculiar to human persons and their bodies. It holds between rivers and aggregates of water molecules, between statues and pieces of marble, between genes and groups of DNA molecules, between stop signs and octagonal pieces of metal. If x constitutes y at t, then x and y are spatially coincident at t, but they not identical. If x constitutes y at t, then x and y have different persistence conditions. Identity is a necessary relation; constitution is contingent. (Indeed, I use the notion of constitution to solve problems that others try to solve by notions of contingent identity, temporal identity, relative identity and so on. The idea of constitution has an advantage over these other views in that the idea of constitution does not compromise the classical notion of identity in its strict Leibnizian form.) I provide a definition of ‘x constitutes y at t’ in order to show that the idea of constitution-without-identity does not suffer from obvious incoherence.
If x constitutes y at t, then x and y share many of their properties: x weighs 100 lbs. at t if and only if y weighs 100 lbs. at t; x is worth $10,000 at t if and only if y is worth $12,000 at t. Each of these properties has its source in either x or y. If a piece of bronze constitutes a statue at t, then what exists at t is a statue-constituted-by-a-piece-of-bronze, whose weight has its source in its being (constituted by) a piece of bronze, and whose value (usually) has its source in its being a statue. This observation leads to the notion of ‘having properties derivatively.’ The piece of bronze has its weight nonderivatively; the statue has its weight derivatively. The statue has its value nonderivatively; the piece of bronze has its weight derivatively. To have a property derivatively is to constitute, or be constituted by, something that has the property independently of its constitution-relations. Only some properties are subject to being had derivatively. All this is spelled out in two definitions. The notion of having a property derivatively explains why if x and y both weigh 100 lbs. at t, and x and y are not identical, it does not follow that there is an object that weighs 200 lbs. where x is at t.
The idea of constitution is decidedly nonreductive. As long as x constitutes y, x has no independent existence. If x continues to exist after the demise of y, then x comes into its own, existing independently. But during the period that x constitutes y, “what the thing really is”—y, constituted by x—is determined by the identity of y. So, what is in front of you when you go to a museum is a statue (constituted, perhaps, by a piece of bronze). What the thing most fundamentally is a statue; but it is constituted by a piece of bronze.
Chapter 3 develops the notion of a first-person perspective. A first-person perspective is the ability to think of—to conceive of—oneself in the first-person without recourse to any name or description or demonstrative. A first-person perspective is necessary for any form of self-consciousness, and is sufficient for some forms of self-consciousness. Evidence that a being has a first-person perspective comes from the person’s ability to think a thought expressible as, e.g., “I wonder how I shall die.” The second occurrence of ‘I’ in a first-person sentence, with a psychological or linguistic verb and an embedded first-person sentence indicates that the being has a first-person perspective.
Nonhuman animals are conscious (some chimpanzees may even be able to refer to themselves), but as far as we can tell, they do not have first-person perspectives in the sense. They don’t wonder how they will die, or hope that they have a painless death or any other such thing. I argue for the irreducibility of the first-person perspective, and argue that other views of self-consciousness (e.g., Rosenthal’s, Armstrong’s, Dennett’s) are inadequate.
Chapter 4 applies the notions of constitution and of a first-person perspective to the issue of human persons. A person is a being with first-person perspective; a human person (at t) is a person constituted by a human body (at t). Human persons are essentially embodied; they can never exist without some body or other, but they do not necessarily have the bodies that in fact constitute them. E.g., it is possible that parts of a person’s human body are replaced by bionic parts until the person is no longer human; still the same person would continue to exist (now constituted by a bionic body) as long as the first-person perspective stayed intact.
So, although a human person cannot exist unembodied, she may come to be constituted by a different body from the one that actually constitutes her. If she came to be constituted by a bionic body, she would no longer be a human person. But she would still be a person as long as she existed. A human person is most fundamentally a person, not an animal—just as a bronze statue is most fundamentally a statue, not a piece of bronze. Two separate human persons that exist at the same time are individuated by their bodies. A human person’s body at a time distinguishes her from all other separate persons at that time.
A human person and the body that constitutes her are a unity, in the same way that a bronze statue and the piece of bronze that constitutes it are a unity. Unlike the statue, however, I have a first-person relation to my body. Properties that my body has nonderivatively are my properties derivatively. E.g., I have the property of being left-handed and of having brown eyes derivatively; the nonderivative bearer of these properties is my body. When I attribute to myself such properties, I am thinking of myself-as-my-body. On the other hand, .I have the property of being employed or of having asked a question nonderivatively; my body is the derivative bearer of these properties. When I attribute to my body properties that I have nonderivatively, I am thinking of my-body-as-myself.
Chapter 5 discusses the vexing problem of personal identity over time. In virtue of what is a person P1 at t1 the same person as a person P2 at t2? I canvass candidate answers to this question, and show that each fails: (1) sameness of person consists in sameness of body, (2) sameness of person consists in sameness of living organism (Animalism), (3) sameness of person consists in sameness of brain, (4) sameness of person consists in psychological continuity, (5) sameness of person consists in sameness of immaterial soul.
Then, I discuss my own view: sameness of person consists in sameness of first-person perspective. Alas, my own view does not provide an informative criterion either. Although I can characterize noncircularly what it is to have a first-person perspective at a time, I know of no noncircular characterization of sameness of first-person perspective over time. Since nobody has an adequate and informative criterion of personal identity over time, I conclude that there is no adequate and informative criterion of personal identity over time: Sameness of person is not reducible to sameness of anything nonpersonal.
Nevertheless, construing personal identity in terms of sameness of first-person perspective has its advantages. First, it avoids problems besetting the other views (e.g., species chauvinism, the duplication problem). Second, it accords well with our self-understanding: there is a fact of the matter whether some future individual is I, and that fact of the matter does not depend on the nonexistence of someone else. Finally, the idea of sameness of first-person perspective ties what it is to be a person over time with what it is to be a person in the first place.
Chapter 6 discusses the importance of personhood. Only persons can be moral agents or rational agents. Persons have many cognitive and practical abilities that beings lacking first-person perspectives lack. Only beings with first-person perspectives can know that they are going to die; only such beings can envisage alternative possibilities for their own futures, or seek self-understanding. Only beings with first-person perspectives can have ideals or can try to change themselves to conform better to their ideals. Human persons are not only the products of evolution, but (unlike any other finite beings) only human persons can deliberately change the course of evolution—not only by artificial breeding, but more directly by genetic engineering.
Chapter 7 defends the coherence of the general idea of constitution (without identity) from a number of published criticisms. Here are two examples. First is the criticism that two things consisting of the same atoms (e.g., a statue and a piece of bronze) cannot differ in kind; this criticism is answered by a discussion of essential properties. Second is the criticism from counting: that if x is spatially coincident with y, and x ¹ y, and x is a statue and y is a statue, then where x is there are two statues. The second criticism is answered by a discussion of the distinction between having a property derivatively and having a property nonderivatively. Also, Chapter 7 discusses criticisms stemming from mereology and supervenience.
Chapter 8 defends the coherence of the application of the idea of constitution to human persons. I discuss the misleading conception of constitution (which I have spelled out in detail) as mere coincidence of two different thing, another version of the “how many” problem, a charge of linguistic incoherence stemming from the reference of ‘I’. I show at length that the Constitution View has a coherent account of the relation between an early-term fetus and the person that it comes to constitute later. Finally, I reply to a counterexample concerning ghosts made of ectoplasm.
Chapter 9 concludes the book with reasons to accept the Constitution View. It really is a materialistic view. It can accomplish almost everything that a dualist wants without the burden of dualism. It takes persons seriously in a specified sense: Being a person is relevant to the fundamental kind of individual that one is; elimination of any person would be elimination of an individual; having mental states is relevant to what a person is. No other materialist view takes persons seriously in all three of these respects.
The Constitution View explains how it is that, although we are set apart by our first-person perspectives, we are still animals. Hence, the Constitution View locates human persons in the material world. The general idea of constitution (without identity) allows for a metaphysics that is both materialistic and nonreductive. This general conception of constitution supports an ontological pluralism that honors the genuine variety of kinds of individuals in the world.