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Identity And Universals: A Conceptualist Approach to Logical, Metaphysical, and Epistemological Problems of Contemporary Identity Theory
Chapter 1, Prior Commitments And Their Puzzles
by Carolyn Ray

Date: 11 Nov 98
Copyright: Carolyn Ray

The study of identity is usually motivated by puzzle cases in which our intuitions or our epistemological principles of judgment seem to fail. An effort is then made to adjust those principles and intuitions to fit these cases.

This study proceeds a little differently. Puzzle cases from mainstream identity literature are listed in this chapter, not in order to motivate the study of identity, but to begin to reveal the philosophical commitments that produce them. My intention is to motivate a shift toward a philosophical stance that will produce less puzzling results in identity theory.

The puzzles fall into several broad categories. A selection of puzzles in each category are listed here. Because the prior commitments discussed in this chapter are deeply entrenched in mainstream philosophy, the solutions to the puzzles they generate must be carefully defended through the analysis of both the concepts involved in the puzzles and of the mainstream concepts of method; this is the work of the remaining chapters. In other words, this chapter is just a tease; no definitions or explanations of terms will be offered at this point. I will just assume that you know what the puzzles mean, and that if you do not, you will at least pretend to believe that they mean something. This will give you a good feel for what it is like to read identity theory literature. (Of course, the pedantic reader can look terms up in the glossary provided at the end of this work; but that would ruin the sheer thrill of reading one baffling puzzle after another. I leave it to your discretion.) Nor will I tell you here what my own commitments are; I will build a case for them as I question the commitments of others.

Logical Possibilism

Brain Transplant Puzzles

Consider the common sense hypothesis that human beings are such that they come with one body, one brain, and one person, and that is the end of it. That just might be mistaken. After all, the sentence, 'Persons can change bodies' is not self-contradictory. Furthermore, some people have their brains divided in two and can function normally with either one, so clearly it is possible for a body-change to happen even if we are not sure how to do it. Then a puzzle arises:

Only technological (and perhaps some moral) difficulties prevent a brain being divided into two, one hemisphere being transplanted to a new skull, the other to another. In such a case, our usual criteria of personal identity--bodily or psychological continuity--would break down. For they would present us with two (over time) equally eligible, but (at a given time) bodily and psychologically quite distinct candidates for the continued identity of the original person (Rey, "Survival,"p. 41).

Subatomic Puzzles

With the dawn of the new physics, twilight has fallen on the classical philosophers's notion of the unity of the person. Not only must we give up our old habit of recognizing persons based on their bodies; we must give up spatiotemporal continuity as the basic criterion of identity. The electron provides a good counterexample to the criterion of spatio-temporal continuity, because:

The identity of the subatomic particles that make up physical objects does not seem to involve spatiotemporal continuity. To begin with, as Hanson has argued, the movement of an electron to a wider orbit involves discontinuous motion. So we have here a case of an electron at t1 identical with an electron at t2 (in a wider orbit), and yet not spatiotemporally continuous with that earlier electron....

Realism Versus Nominalism

Borderline Case Puzzles

If anything is a natural kind, person is. But if a person can lose some brain cells without dying, might we not gradually take all of one person's brain cells and put them into another person's head and thus transfer the person? Let us suppose that we have Albert Einstein's brain preserved in stasis, and that we have a willing victim in the person of a contemporary professor of philosophy--call him 'Peter Unger.' How will we tell who is who, if there is a gradual replacement of his brain-cells with those of Einstein? Surely there would be a question at some point in the procedure as to which person, Unger or Einstein, was now associated with Unger's body. Thus we see that our ideas about this so-called "natural kind" are quite confused.

Naming And Counting Puzzles

There is a cat named 'Tibbles' on the mat; she has 1,000 hairs. Call the largest lump of continuous feline tissue on the mat 'c'. The part of c that contains all but one hair is c1. Remove another hair, and call the result c2--and so on up to c1,001. Since c is just a cat, and removing a hair from c does not generate a new cat, c1 must already have been on the mat too. But then there must have been 1,001 cats on the mat all along. But this cannot be right; we do not talk this way about cats. So it must be that there is just one cat, and each of the lumps of feline tissue, though not identical to each other, are the same cat as any other. And now we have to give up Leibniz's Law.

Skepticism with Regard to Universals

Metaphysical Definition Puzzles

Some identity theorists have claimed that what makes a person and the same person is having the same memories. Harold Noonan, however, asks us,

How is this distinction to be made if not by an appeal to personal identity? If so, however, memory not only entails but presupposes personal identity: in the sense that the conclusive verification of the proposition that someone genuinely remembers F-ing must involve the conclusive verification of the proposition that he, the same person, did indeed F. To know that someone genuinely remembers F-ing one must know that he F-ed. Consequently personal identity cannot be defined in terms of memory since one must already be in possession of the concept of personal identity, and be able to determine that it applies, in order to be in a position to operate with the concept of memory at all (Noonan, pp. 13-14).

If we cannot tell whether someone really has genuine memories rather than false ones, then memory cannot be what a person is.

The Analytic/Synthetic Dichotomy

Mind-Free Person Puzzles

There is yet more reason to doubt spatiotemporal continuity as any sort of ingredient in or means of establishing identity. Suppose that a person can divide the way an amoeba does, and Thelma commits a crime, and then divides. Both of the new people are continuous with the first, and since the first committed crime x, therefore both new people committed crime x. But that means that both persons had to have been present at the crime, and the only way for that to have happened is if both "cohabitated" the original body. (see, e.g., Mills, 1993). Thus, we can see that either the criterion of spatiotemporal continuity is incorrect, or that our ordinary notions about persons are incorrect.

Mind-Free Logical Puzzles

Frege: According to Gottlob Frege, if identity is taken to be a relation that holds between every object and itself, a paradox arises: the statement 'a=a' is an obvious tautology, and not an extension of our knowledge in the least; the statement 'a=b' is not a tautology, but rather an extension of our knowledge. But if 'a' is the name of the same object that 'b' is the name of, and identity is just that relation that holds between every object and itself, then we cannot explain the difference in cognitive content between the two statements.

Russell: In an analysis of propositions, Bertrand Russell proposed the following logical conundrum:

George IV wished to know whether Scott was the author of Waverley.

The author of Waverley is Scott.


.:George IV wished to know whether Scott is Scott. (Russell, On Denoting, p. 108).

But George was interested in authors and books, not in the law of identity! So not only is Leibniz's Law uninformative, but it fails to preserve truth in arguments as well.

Theories of Ethics

Derek Parfit steps into a transporter that makes a blueprint of his body and then destroys it. The blueprint is transmitted to Mars, where he steps off the transporter. Clearly, he is the same person, but his body is made of completely different matter, and did not exist for some time. So bodily identity--even personal identity--is not what matters. All that matters is that one's pet projects be completed, and it does not matter who does them. Therefore, the boundaries between persons are not what we thought they were (one person to a body, one body to a person, and one set of mental characteristics per each), and in fact are quite indeterminate.

The puzzles listed here are fairly easy to resolve given the right approach. Because commitments to theories can be part of the problem, it will be necessary to uncover those commitments. This will clear the ground for the development of the alternative approach.

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