Here's a fun puzzle case that's been (independently) suggested to me by a couple of different people recently. Consider Moe, a relatively intelligent monkey, and his psychological counterpart Hugh, a severely retarded human. Let's stipulate that, despite their differing species, they are psychological duplicates: they have all the same experiences, thoughts, and feelings. This is at least conceivable. Now suppose we can cognitively enhance just one of them, to turn them into a rational person. Do we have any (non-instrumental) reason to prefer enhancing one of them over the other? Would one of them benefit more, for example, or have a stronger moral 'claim' to such treatment?
It's very intuitive to think that we'd do better to help the human here. (And not just because of rank speciesism: I trust that the intuition would carry over even if Hugh were a retarded instance of an intelligent alien species.) Moe has [teleologically] 'normal' intelligence for the kind of being he is, whereas Hugh is disabled. If we take these teleological, kind-based categorizations seriously, then we're apt to think that what would be 'enhancement' for Moe is treatment for Hugh, and treatment takes priority over enhancement. But should we take those categorizations seriously?
There's something bizarre about the claim that two individuals with qualitatively identical psychologies could differ in their cognitive (dis)ability status, in any sense that really matters. Sure, we could evaluate individuals on a species-relative scale. But isn't there something unacceptable arbitrary about that? Isn't it more principled to evaluate them in their own right, looking only at their individual qualities?
Charles Johnson responds that we "have to distinguish between the cases where a faculty is present but unexercised, damaged, frustrated, undeveloped, etc. and those in which there isn't any faculty to lament the damaging of at all." In other words, perhaps there's an intrinsic difference in the two minds after all. On this proposal, Hugh has a damaged capacity for rationality, whereas Moe has no such capacity at all.
The main problem with this proposal is that it appears baseless. In general, the distinction between present-but-dormant dispositions and absent-but-acquirable dispositions strikes me as philosophically murky. Maybe in this case we could make clear sense of it if there was an appropriate neurobiological difference between the individuals: say if Hugh's brain (but not Moe's) contained all the "wiring" necessary for advanced cognition, and all we needed to do was restore a broken "connection" of some sort. But it seems we could stipulate away any such blatant physical difference: just consider a case where Hugh's brain is actually as small and limited as Moe's, would be just as difficult to improve, etc. Maybe you could try to look further back, say to the level of DNA, and argue that Hugh's DNA shows greater potential for intelligence than Moe's does. I guess that's the most promising option for the teleologist here, but we're now appealing to facts so distant from the actually manifest individuals that it's hard to credit these subtle differences with any great normative significance. (It seems an awful stretch to say that it's a significant difference between the two minds that one of them arose from DNA that could once have been more easily tweaked to produce a rational being in place of the creature that exists today. That doesn't sound much like a present-but-dormant capacity to me.)
The final option for the teleologist here is to turn to speculative metaphysics. Whatever qualitative, physical differences we may or may not find between how these two beings happen to be, it's a deep fact that they differ in what (fundamental kind of being) they are. [My evil twin explains this distinction in more detail here.] Hugh is essentially a human being - thus rational in kind - however severely underdeveloped he might happen to be in his actual manifestation. Moe, by contrast, is simply a non-rational creature, rather than a defective manifestation of a rational creature. This divergence is reflected in our intuitive judgments that cognitive enhancement would merely constitute development (change within his kind) for Hugh, whereas to enhance Moe would transform him into an entirely different kind of creature.
It's worth noting that anyone who accepts this sort of framework should probably also consider embryonic death to be a significant intrinsic bad, for the reasons given by my evil twin. So that's pretty counterintuitive. And I personally find the speculative metaphysics a bit much to swallow. Still, it does seem to explain our cognitive enhancement intuitions pretty well. If on reflection we reject the speculative metaphysics (as I think we should), then we can use it to give an 'error theory' of our initial intuition in favour of Hugh. Really the stark individualist picture is correct, and we should be indifferent between the two options. But we're tempted to favour Hugh because our intuitions are driven by this metaphysical mistake, which leads us to see Hugh as "deprived" in some way that Moe is not.
What do you think?