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 personal identity who believes in acting in an impartial fashion towards others would behave in exactly the same way. I don't see how reductionism adds anything.
The argument that we ought to behave in an impartial fashion towards other people because personal identity isn't a coherent concept reminds me of the argument that we ought to not be racist because race isn't a coherent concept. I thought that racism was wrong long before I ever considered whether race was a coherent concept or not, and I thought partiality was wrong before I thought about the coherency of personal identity. I don't see either argument as giving me any additional reason to oppose those things.
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.
It's not fundamentally linked in some sort of ghost-in-a-machine sense. But "my" future experience is linked in ways that "their" future experience is not. To put it in reductionist lingo, the unit that is processing the current experiences expects to evolve into the unit that will process those future experiences, while retaining many of its original properties.
Another way of putting it is that I think of myself as a four-dimensional object, which has boundaries in both space and time. It's true that these boundaries are fuzzy. They are not sharp, well-defined, or ontologically fundamental. But they are there nonetheless. And saying that FutureMe is the same person as PresentMe but FutureObama is not makes just as much since as saying that PresentMe is me, but PresentRubberDuckyOnMyDesk is not. The rubber ducky on my desk is a different three dimensional object than me, and Barack Obama is a different four dimensional object than me.
Note that there can be differences in the average intensity or frequency of response to one's own plight, versus that of others
If you truly reject the concept of personal identity it's not really possible to respond to anything. The very act of thinking about how to respond "kills" thousands of yous and creates new yous before the thought is even complete. I think that the 4D object concept makes much more sense.
Now, you might wonder why I make such a big deal about this, if I believe that ethics prescribes the exact same behavior regardless of the coherency of personal identity. It's because, as I said in my previous post, in population ethics I believe personal identity is the most important thing there is. For instance, I believe that a world where a person lives a good long life is better by far than one where a person dies and is replaced by a new person who experiences the same amount of wellbeing as the dead person would have if they'd lived. The fact that both scenarios contain the same total amount of wellbeing is not relevant.
I thought partiality was wrong before I thought about the coherency of personal identity. I don't see either argument as giving me any additional reason to oppose those things.
That's not my argument - rather, I simply point out the highly limited usefulness of dividing the space of concerns into "altruistic" versus "self-interested" categories. These are not two different kinds of concerns (at least to a clear-headed reductionist), they are just two different locations, or directions of concern. Without locating the concern in a hi...
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?