Bodily Continuity and Personal Identity
Chapter – 2
- Coburn critiques an argument about personal identity based on sudden changes in a person’s character and memory claims, specifically addressing whether such changes can justify identity identification.
- The argument posits that if person A undergoes a change that makes them identical to B, and C undergoes a similar change, both A and C could be identified as B. This leads to the absurdity that A = C, implying that A and C are the same person, which is not reasonable.
- To avoid this absurdity, the argument suggests abandoning the identification of A with B and C with B. However, Coburn claims this reasoning leads to undesirable conclusions when applied to other cases.
- Coburn uses the example of a person George who disappears, and shortly afterward, an individual, George*, appears that is indistinguishable from George. Coburn argues this identification should not be vacuous, as there would be significant consequences (e.g., regarding George’s crimes).
- The author clarifies that by vacuous, they mean there would be no proper grounds for making the judgment of identity between A and B, not that no consequences would follow from such a judgment.
- The argument is that there should be grounds for identifying someone based on more than mere exact similarity, especially when such judgments carry consequences.
- Coburn’s objection implies that identity identification between George and George* is justified under certain conditions, which calls into question the original argument.
- The author notes that Coburn’s case would only be a valid counter-example if the circumstances of George’s disappearance and the appearance of George* are restricted (e.g., if George* appears shortly after George’s disappearance and in the same location).
- If the case is restricted to a short interval and same location, the principle of identity involving memory and character claims still fails to satisfy the necessary one-one relation for identity, as it is a many-one relation.
- The original argument suggests that for a criterion of identity to be valid, it must involve a one-one relation. This ensures that identity can be uniquely determined without ambiguity.
- The author argues that memory and character-based identity criteria fail because they do not establish a one-onerelation, allowing multiple individuals to be considered identical.
- To make Coburn’s example work as a valid criterion of identity, it must be restricted. A modified version stating that the person must appear in all respects similar to, and in the same place as the previous occupant can pass the test, provided certain conditions about location are met.
- For the location condition to be valid, it must be restricted to ensure no two people can simultaneously occupy the same place, and it must be sufficiently specific to avoid ambiguity about the exact place in question.
- The length of time between disappearance and reappearance in Coburn’s example introduces the issue of determining the same place.
- A short lapse of time makes it clearer what “same place” means, as a longer time might lead to ambiguity (e.g., if the bed is moved to another room or house).
- Coburn may introduce a brief lapse to make the concept of “same place” more determinate, but this also raises a dilemma: if too much time passes, why should the place of appearance be privileged for identity?
- The author argues that applying a criterion of identity based on the place of appearance becomes arbitrary over longer time spans, leading to difficulties in using “same place” as the basis for identity.
- The issue arises because we may be unconsciously using a model based on real-world assumptions, where a person who disappears still exists and could move to a different place, creating an illusion in the application of identity criteria.
- If Coburn’s principle allows for reduplication, it cannot be logically consistent since two individuals cannot both occupy the “same place” in the required sense. Thus, Coburn’s principle may be unrestricted in space and time.
- A restricted principle that limits time and space could satisfy the logical requirements for identity but would not allow for reduplication, making Coburn’s case not a valid counter-example.
- If the principle is restricted only in space but not time, it could still fulfill the logical requirements but would be philosophically unsatisfactory.
- The possibility of reduplication in the criterion of spatio-temporal continuity raises an objection, as even with this criterion, there could be cases where multiple entities appear, such as in the case of an amoeba splitting.
- Despite the possibility of reduplication, applying the spatio-temporal continuity criterion involves historical inquiry, tracking the continuity of an object through time, which can reveal if duplication occurs.
- In cases like an amoeba splitting, the application of the continuity criterion would show that the resultant entities are not strictly identical to the original, as the fission interferes with continuity.
- The author argues that the spatio-temporal continuity criterion can reveal reduplication, unlike memory or character-based identity criteria.
- For objects with strong empirical reasons against reduplication, like billiard balls, we do not need to engage in a thorough historical investigation to answer identity questions, but for cases like amoebas, careful observation is necessary.
- The conclusion is that a criterion of identity must establish a one-one relation (not a many-one relation) to distinguish identity from exact similarity.
- Without a one-one relation, it is impossible to preserve the distinction between identity and exact similarity.