I want there to be other people in the future, but this is purely for idealistic and altruistic reasons, not because of any form of self-interest.
I think that on the reductionist understanding of personal identity, that distinction breaks down. Consider a fairly typical "altruistic" act: I see a person heavily loaded with packages and I hold the doors open for them. Why? Well, I can see that it would suck badly to have to deal with the doors and packages simultaneously, and that it would suck a lot less to deal with the doors and packages separately. Now consider a fairly typical "selfish" act, where I plan to bring some packages into my building, so I prop the doors open beforehand. Why? Because I can see that it would suck badly to have to deal with the doors and packages simultaneously ... There isn't a lot of attention to the underlying facts of same memories, personality, etc. - the reduction-base for personal identity according to reductionism - in either case. Instead, the focus is on the quality of experiences and activities of the person(s) involved.
If you're a non-reductionist who believes in a fundamental metaphysical ghost-in-the-machine, you could assert that there's some extra step of indirection in the altruistic case: that person's experience would be similar to mine - which distinguishes it from the selfish motivation. But that's not the case for the reductionist, or more precisely, the indirection applies in both cases because neither future experience is fundamentally linked to my-experience-now.
Note that there can be differences in the average intensity or frequency of response to one's own plight, versus that of others, without there being any difference in kind in those cases in which "altruistic" motivations do occur. Similarly, there can be, and typically are, differences in the intensity and frequency of response to one's own near future versus one's farther future.
I think that on the reductionist understanding of personal identity, that distinction breaks down. Consider a fairly typical "altruistic" act: I see a person heavily loaded with packages and I hold the doors open for them ... There isn't a lot of attention to the underlying facts of same memories, personality, etc. - the reduction-base for personal identity according to reductionism - in either case. Instead, the focus is on the quality of experiences and activities of the person(s) involved.
A person who has a non-reductionist understanding of...
Although Elizier has dealt with personal identity questions (in terms of ruling out the body theory), he has not actually, as far as I know, "solved" the problem of Personal Identity as it is understood in philosophy. Nor, as far as I know, has any thinker (Robin Hanson, Yvain, etc) broadly in the same school of thought.
Why do I think it worth solving? One- Lesswrong has a tradition of trying to solve all of philosophy through thinking better than philosophers do. Even when I don't agree with it, the result is often enlightening. Two- What counts as 'same person' could easily have significant implications for large numbers of ethical dilemnas, and thus for Lesswrongian ethics.
Three- most importantly of all, the correct theory has practical implications for cryonics. I don't know enough to assert any theory as actually true, but if, say, Identity as Continuity of Form rather than of Matter were the true theory it would mean that preserving only the mental data would not be enough. What kind of preservation is necessary also varies somewhat- the difference in requirement based on a Continuity of Consciousness v.s a Continuity of Psyche theory, for example should be obvious.
I'm curious what people here think. What is the correct answer? No-self theory? Psyche theory? Derek Parfit's theory in some manner? Or if there is a correct way to dissolve the question, what is that correct way?