Shelly Kagan considers: why is death bad?:
Maybe … death is bad for me in the comparative sense, because when I’m dead I lack life—more particularly, the good things in life. … Yet if death is bad for me, when is it bad for me? Not now. I’m not dead now. What about when I’m dead? But then, I won’t exist. … Isn’t it true that something can be bad for you only if you exist? Call this idea the existence requirement. …
Rejecting the existence requirement has some implications that are hard to swallow. For if nonexistence can be bad for somebody even though that person doesn’t exist, then nonexistence could be bad for somebody who never exists. … Let’s call him Larry. Now, how many of us feel sorry for Larry? Probably nobody. But if we give up on the existence requirement, we no longer have any grounds for withholding our sympathy from Larry. I’ve got it bad. I’m going to die. But Larry’s got it worse: He never gets any life at all.
Moreover, there are a lot of merely possible people. How many? … You end up with more possible people than there are particles in the known universe, and almost none of those people get to be born. If we are not prepared to say that that’s a moral tragedy of unspeakable proportions, we could avoid this conclusion by going back to the existence requirement. …
If I accept the existence requirement, death isn’t bad for me, which is really rather hard to believe. Alternatively, I can keep the claim that death is bad for me by giving up the existence requirement. But then I’ve got to say that it is a tragedy that Larry and the other untold billion billion billions are never born. And that seems just as unacceptable. (more)
Imagine a couple had been looking forward to raising a child with their combined genetic features, but then discovered that one of them was infertile. In this case they might mourn the loss of a hoped-for child who would in fact never exist. Not just the loss to themselves, but the loss to the child itself. And their friends might mourn with them.
But since this is a pretty unusual situation, we humans have not evolved much in the way of emotional habits and capacities to deal specifically with it. Our emotional habits are focused on the kinds of losses which people around us more commonly suffer and complain. So naturally we aren’t in the habit of taking time out to mourn the loss of a specific Larry. But there are lots of people far from us whose losses we don’t mourn. That hardly means such losses don’t exist.
It seems to me Kagan’s attitude above amounts to insisting that is impossible to imagine a vastly better state (of the universe) than our own. After all, if a vastly better state that ours is “possible”, then the fact that our actual state is not that possible state is a terrible “tragedy”, which he will just not allow.
But if possible states can vary greatly in the amount of good they would embody, then it is almost certain that the good of our actual state holds far less than the maximum good state. This only seems to me a “tragedy”, however, if we could have done something specific to achieve that much better state.
If we can’t see what we could do to allow substantially more creatures to exist, then it isn’t a tragedy that they don’t exist. It is a loss relative to an ideal world where they could exist, but it isn’t a tragedy not to know to create implausibly ideal worlds.