PHIL 101 INSTRUCTOR: WILBURN MODEL ANSWERS TO PUBLISHERS’ ESSAY TEST FOR CH. 4

1. If two persons could inhabit the same body, would this show that animalism is false? Why or why not?

Yes it would. Animalism maintains that having a particular body is sufficient for being a particular person. If more than one person inhabited a given body, this sufficiency condition would be violated, as it would show that inhabiting a particular body is not enough to identify a particular person.

2. If your DNA were fused with that of a cat so that eventually you had the body of a cat (and your mind was left intact), would this show that animalism is true? Why or why not?

This would not show that animalism is true. Indeed, depending on how you describe the case, it might be seen as a counterexample to animalism. Again, animalism maintains that having a particular body is sufficient for being a particular person. If your DNA were fused with that of a cat, then you would arguably come to acquire a different body while still remaining the same person. Thus, animalism would be refuted.

3. If your memories were erased but your soul remained intact, would you still be the same person? Why or why not?

Intuitively, it seems that you would not be the same person. To remain the same person seems to have everything to do with maintaining psychological continuity over time, irrespective of whether or not this psychological continuity is implemented in the same individual mental substance over time. To imagine losing all of your memories is to effectively imagine going out of existence whether or not the mental substance or soul in which these thoughts and memories occur continues to exist.

4. Explain why the possibility of a soul switch suggests that the soul theory is false.

Soul switching thought experiments are imagined cases in which one’s thoughts and memories are transferred from one mental substance to another. The point of such thought experiments is that what seems to matter to personal identity is the retention of memories and mental continuity, irrespective of whether or not these things occur in a particular mental substance. This point is made by both Locke and Kant. If one imagines the contents of one’s consciousness being transferred from one mental substance to another mental substance, one imagines one’s self traveling with the contents of one’s mental life rather than remaining with the original container of this mental life.

1 5. Explain John Hick's point about souls and how heredity and environment seem to account for all of an individual's character traits.

Hick’s point is that we would only have reason to postulate the existence of souls if we needed to invoke souls to explain the occurrence of those properties which make individual persons the persons that they are. But all of these properties seem to be explained by heredity and environment. Thus, the postulation of souls has no explanatory value.

6. How does William's thought experiment about Guy Fawkes undermine the psychological continuity theory?

The Guy Fawkes thought experiment shows that psychological continuity is a one-to-many relationship, since we can easily imagine more than one person being psychologically continuous with Guy Fawkes. But numerical identity is a one-to-one relationship. Thus, personal (numerical) identity cannot be analyzed in terms of psychological continuity.

7. What is the reduplication problem?

The reduplication problem is, in effect, the very problem posed by the Guy Fawkes example and other thought experiments (e.g., Parfit’s transporter tale) designed to press the same moral. The problem is that since psychological continuity is a function of qualitative similarity over time (via an interlinking series of psychologically connected persons), psychological continuity is a one-to-many relationship. But, once again, numerical identity is a one-to-one relationship (since one thing cannot be numerically identical to anything other than itself). Thus, personal (numerical) identity cannot be analyzed in terms of psychological continuity.

8. What does Parfit's transporter tale show about personal identity?

The transporter tales has us envision a machine that scans a person and reproduces his structural details in new matter. In reproducing his structural details, it automatically reproduces his psychology (the set of quasi-memories and quasi-desires that characterize him at the moment of scanning). But in doing this, it creates a situation in which two people simultaneously exist (i.e., the original and the duplicate) who are psychologically continuous with the original. Once again, this shows that psychological continuity is a one-to-many relationship. And since numerical personal identity is a one-to-one relationship, personal (numerical) identity cannot be analyzed in terms of psychological continuity.

9. What is the insufficiency objection?

The insufficiency objection maintains that personal identity determined not only by memories, but also by values and desires. This is because an individual may often be said to be replaced by

2 another in light of a substantial change in driving values, desires and goals. Because many desires are defined in self-referential terms, however, we must be careful to avoid circularity in any account of personal identity which takes them into account. We can do this by invoking the notion of quasi-desires, desires that are caused in the right way by actual desires. We can then say that persons x and y (at two different times) are identical if and only if they form part of an overlapping series of persons who share quasi-memories and quasi-desires. Quite a mouthful, I grant.

10. What is Locke's view of memory, crime, and personal identity?

On Locke’s account, a person p1 can be identical with a person p2 at two different times only if they share one or more memories. Because of this, Locke is convinced that no one can be rightfully punished for performing acts he or she does not remember. He concedes that proclamations that one does not remember doing something are not generally treated as excuses in court, but this is only because we generally suspect such proclamations to be dishonest.

11. Explain the brain theory of personal identity.

On the stupidly named “brain theory”, identical persons have continuous psychologies caused by and realized in the same brain. The motivation for this account is to avoid the sorts of problems described in (1), (2) and (3) above by tying psychological continuity to particular substances which remain numerically identical with themselves (thus avoiding one-to-many identity relations).

12. Explain why Parfit says that numerical identity is not what matters in survival?

If numerical identity were what really mattered in survival, then (in order to preserve one-to-one relationship) Parfit would be motivated to kill any left-over duplicates of himself that might arise through the multiple reimplementation of his psychology. But because Parfit thinks this is ridiculous (in light of “the only x and y principle”), he judges that identity cannot be what is important to survival. Because all of one’s duplicates would be psychologically continuous with one, they should all be seen as one’s survivors, and the existence of any or all of them should be viewed as preferable to personal death.

13. Explain what split-brain experiments show about the brain theory.

They (allegedly) show that the “brain theory” is false, since it fails to circumvent the problems which it is invoked to solve. These problems arise in connection with duplication scenarios on which one’s psychology is reimplemented in more than one body, violating the conviction that identity is necessarily a one-to-one relation. The brain theory attempts to solve these problems by tying psychological continuity with particular neural substrates which must remain numerically identical with themselves (thus avoiding one-to-many identity relations). But split-brain

3 experiments raise the possibility that even when persons are so conceived (i.e., as psychologies caused by and realized in specific brains), duplication might still be possible. Imagine that one’s corpus callosum is cut and each of one’s two hemispheres is appropriately wired into the skulls of two different bodies. This possibility seems to raise exactly the same problems the counterexamples to the psychological continuity theory (e.g., Williams’ Guy Fawkes, Parfit’s transporter, etc.).

14. Can personal identity consist in either psychological or physical continuity? Why or why not?

It wouldn’t seem so. Psychological continuity theory allows for duplication cases and the subsequent violation of the constraint that identity must be a one-to-one relation. Physical continuity doesn’t seem to latch onto anything truly essential to personal identity, as the specific body or brain I possess would seem to be incidental to who I am. The “brain theory” endeavors to fuse psychological and physical (neural) identity criteria to account for personal identity, but it is ultimately unable to avoid precisely the kinds of duplication cases that prove so fatal to pure psychological identity theory.

15. Explain the only x and y principle.

The “only x and y principle” maintains that if x and y are identical, then they are identical by virtue of the features of x and y alone, irrespective of whatever else may be true of anything else in the universe. The principle is important when we consider various duplication thought experiments, which seem to suggest that whether or not a person at one time is identical to a person at another time is somehow a function of whether or not there happen to be any additional duplicates left lying around (as in Guy Fawkes cases, transporter cases, etc.).

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