In answering question 24759, Michael Cholbi writes: "It's important not to confuse the facts by which others know or identify a person and the facts that constitute his or her identity as a person. The way you and I think about Nelson is in terms of social facts about him (his accomplishments, etc.). If I were struggling to remember who was South Africa's first post-apartheid leader, you'd naturally tell me, "Don't you remember? It was Nelson Mandela."" Professor Cholbi intended that as an argument in favour of the theory that "He's not Mandela unless he has that genetic constitution." But suppose we are extremely well informed geneticists and you were struggling to remember who was the person who had the unique sequence of nucleotides CTAG repeated for 999 times between locations 1A237C and 1A324A. I would also tell you: "Don't you remember? It was Nelson Mandela." What is the difference between the genetic and the social fact? Or the difference between genetic constitution and whatever events that occurred in Mandela's mother's womb after that genetic constitution was fixed? Michael Cholbi says: "Mandela's genetic constitution is essential to him. Everything else about him is contingent." But isn't that just assuming what is being asked? A genetic constitution is a causally relevant fact, like any other. Why choose that one for identity? Professor Cholbi didn't give a single argument, did he? I don't ask Askphilosophers to address the possibility of cloning and the cases of identical twins. It is just that I don't have a clue why people have to have "essences" and why such "essences" have to be sequences of nucleotides (or of numbers, for that matter: within a few years, we will only need the sequence of letters (A, C, T, G) to produce a genetically identical organism). Thank you.

Thanks for following up. You're asking about a number of issues at once, so let's see if we can distill them out.

First, you wonder why people must have "essences" at all. That's a big question -- Hume is a well-known philosopher who can be read at suggesting that persons or selves don't exist. That 'no self'' position is a minority view within philosophy, but is arguably the position espoused by Buddha and has some affinities with the 'eliminative materialism' defended by Paul and Patricia Churchland. I'd encourage you to explore those views further.

Second, in my earlier response, the point that we might identify someone on the basis of social facts about him or her was not an argument for genetic facts being essential to a person. Rather, my purpose in making that point is to illustrate how this line of reasoning is invalid:

Whether a is F can be reliably determined by whether a is G. Therefore, G is a's essence.

To see why, suppose (again) that the way we would normally identify Mandela is by reference to social facts about him: his personal history, accomplishments, etc. It wouldn't follow that those social facts constitute Mandela's identity. After all, there are other facts about a person by which we might be able to reliably identify him or her without those facts being essential to that person. I can pretty reliably identify the comedian Carrot Top by his massive orange hair -- but his massive orange hair clearly isn't essential to him. If he cut or colored it, he wouldn't be a numerically different person. So the general point is that even if some fact can be relied upon to identify something, that fact need not be that thing's essence. And that goes for genetic facts too: If I could reliably pick out a person on the basis of her genotype, it wouldn't follow that her genotype is her essence. Of course, if some property is a person's essence then of course we can identify that person by picking out whomever has that property -- but the contrary doesn't follow. So I was not arguing from the claim that we could pick someone out on the basis of her genetic constitution to the claim that her genetic constitution is her essence. That would've been a bad argument!

That said, you're correct that I didn't offer earlier an argument in favor of our genotypes being our essences. And in general, the philosophical dialogue around this issue tends to employ intuitions about what sorts of changes a person can undergo while still remaining that same person over time. As I said, I share some of your skepticism regarding genetic facts being our essence. But for defenders of that view, it seems intuitive to think that while virtually every other fact about a person might change (including social facts) without a numerically distinct person coming into existence, a change in that person's genetic constitution would result in a new, distinct person. If you find that thought intuitive, then you're likely to think that genetic facts are our essence. If not, then it would be worth exploring what's mistaken about that thought.

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