The experience of a subjective thread of consciousness - let's call it STC - is pretty much the experience of experience, or qualia. So Chalmers' experiment is apt.
The relevant fact is that STC is purely subjective. The reason I think you and everyone else have STCs is because you say you do, and it's a simpler hypothesis than the one saying I'm different from everyone else. But the reason I think I have an STC is completely different: I know it from direct experience, which is pretty much by definition incontrovertible. (I may be mistaken about the real world, my experience may not match reality, I may even have false memories, but I can't be literally mistaken about what I'm experiencing right now. Unless you suppose I constantly have false memories of the last half-second and that the induction hypothesis is therefore inapplicable to subjective experience.)
So yes, I can imagine a universe without STCs. By construction, I won't exist in that universe. This is exactly the same question as: can I rule out that no-one else but me in this universe has STCs, or qualia, or consciousness? No, I can't; I can't test the suggestion. But I also can't proceed to the idea that I have no STC, because that would be denying my actual moment-to-moment experience. It would be as pointless as saying I'm colorblind when I'm not.
So to recap, I have no idea how to solve the hard problem of consciousness. I have no idea how to explain the subjective experience and connect it to the objective world, or to test for subjective experiences in somebody else. But I can't pretend consciousness and experience don't exist, either, at least not for me. I hope someone comes along and solves these problems and explains the solution to me - I don't know if this is actually possible, but I hope so - but lack of a solution doesn't make me ignore the problem.
The experience of a subjective thread of consciousness - let's call it STC - is pretty much the experience of experience, or qualia. So Chalmers' experiment is apt.
There's a difference between the questions of STC and of qualia. We might live in a universe where you can have multiple causal descendants, each of them related to you-now in the same way that you-now are to you-one-year-ago, and none of them distinct from the others in a morally relevant way. Of course, each of these descendants would go on to experience qualia. The question of whether t...
From the dawn of civilization humans believed in eternal life. The flesh may rot, but the soul will be reborn. To save the soul from the potential adverse living conditions (e.g. hell), the body, being the transient and thus the less important part, was expected to make sacrifices. To accumulate the best possible karma, pleasures of the flesh had to be given up or at least heavily curtailed.
Naturally the wisdom of this trade-off was questioned by many skeptical minds. The idea of reincarnation may have a strong appeal to imagination, but in absence of any credible evidence the Occam’s razor mercilessly cuts it into pieces. Instead of sacrificing for the sake of the future incarnations, a rationalist should live for the present. But does he really?
Consider the “incarnations” of the same person at different ages. Upon reaching the age of self-awareness, the earlier “incarnations” start making sacrifices for the benefit of the later ones. Dreams of becoming an astronaut at 25 may prompt a child of nine to exercise or study instead of playing. Upon reaching the age of 25, the same child may take a job at the bank and start saving for the potential retirement. Of course, legally all these “incarnations” are just the same person. But beyond jurisprudence, what is it that makes you who you are at the age of nine, twenty five or seventy?
Over the years your body, tastes, goals and the whole worldview are likely to undergo dramatic change. The single thing which remains essentially constant through your entire life is your DNA sequence. Through natural selection, evolution has ensured that we preferentially empathize with those whose DNA sequence is most similar to our own, i.e. our children, siblings and, most importantly, ourselves. But, instinct excepted, is there a reason why a rational self-conscious being must obey a program implanted in us by the unconscious force of evolution? If you identify more with your mind (personality/views/goals/…) than with the DNA sequence, why should you care more for someone who, living many years from now will resemble you less than some actual people living today?
P.S. I am aware that the meaning of “self” was debated by philosophers for many years, but I am really curious about the personal answers of “ordinary” rationalists to this question.