Footnote on Agent-boundaries vs Personal-Identity

Somewhere else, I specified that I am interested in how to draw boundaries between an agent and its environment, and not interested in questions of individuality in the sense of personal identity or selfhood. 

This is an important distinction to make. For example, depending on what question you want to pursue, you will judge a different set of methodological approaches appropriate for tackling your question. It is also relevant when motivating why you want to ask this question in the first place and the nature of the epistemic purchase you might hope to achieve in pursuing this question. 

Even so, - and this is important to note clearly - it is still possible (and we ought to remain open to the possibility) that, in clarifying how to draw boundaries around agents, we in fact clarify things related to personal identity and selfhood. That does not mean that those two questions are secretly the same question and that my earlier distinction is vacuous. Still, in thinking about it, we can realize that we ought not to be surprised if progress on the former question usefully informs discussions on the latter. 

Consider some of the most well-known philosophical thought experiments that are meant to illuminate, or at least motivate, questions concerning personal identity and selfhood. Imagine for example a technologically superior civilization in which it is possible to create an atomically identical copy of myself. (For many more examples of philosophical thought experiments about personal identity, see e.g. here.) What does that imply about my selfhood and personal identity? Are there suddenly now two “Me”s there that exist simultaneously and independently? But how can “I” be in more than one place at once? On the other hand, if we suggest that the two copies represent different identities, based on what can we claim them to be distinct (remember they are identical copies down to the level of atoms)? In other words, what defines my personal identity if not the sum total of everything that constitutes me? But then, we run into a new problem. If we want to claim that “Me” refers to a specific sum total of things that constitute me, in how far can we claim that me-now and me-from-a-few-seconds-ago refer to the same “Self”? It seems like, the more we think about these questions, the more we get into trouble. Patches we used to get to a reasonable-sounding answer in one place “come back to hunt us” by exposing new inconsistencies elsewhere. 

The question we are interested in here is whether better answers to the agent boundaries problem can help us become less confused about situations like the one described above? I don’t know that it will but I think certainly we have reasons to hope so. We might for example hope to get a more principled answer to the question “in how for do me-now and me-from-a-few-seconds-ago point to the same individual, or not?”. If we could come up with fully principled plausible answers in one place, we could use the same principled reasoning in other places. At the very least, this gives us a coherent (even if wrong) picture. From there, we can then figure out what seems wrong with the coherent-but-wrong picture, and make principled updates to the initial answers. This definitely seems better than trying to find ad-hoc patches for local inconsistencies in a way that does not systematically bring us towards a better comprehensive understanding of the question of personal identity.

Let’s be honest. The above consists of a lot of hopeful yet vague gesturing. However, the point I am trying to make is not about any specific claims concerning the personal identity and its relationship to the boundaries of agents. The point is simply to illuminate something about the relationship between these two lines of inquiry. In summary, I claim that while questions of agent boundaries and questions of personal identity are importantly distinct (i.e. not just different ways to ask the same underlying question), they are not independent in that they can inform each other. Personally, I expect that the flow of insight is predominantly directed from boundaries of agents to personal identity, not vice versa. Mostly, I find discussions about personal identity to be even more fundamentally confused than discussions of agent boundaries, and I see fewer solid epistemic strategies for making progress on the former compared to the latter. In other words, I believe we can learn about how to draw boundaries around agents in a principled manner by looking at the actual world (i.e. conducting some form of empiricism). In the case of personal identity, however, the empirically grounded path to the sight seems cluttered with more obstacles that we don’t currently have much traction on resolving anytime soon (e.g. how science can deal with subjectivity).