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 they have qualia is distinct from the question of whether one of them must be the unique inheritor of your STC.
So yes, I can imagine a universe without STCs.
Well, you can’t really. None of us can really imagine a universe. We can imagine a bundle of properties which don’t, so far as we can see, contradict each other. But the caveat “so far as we can see” is important.
The question of whether they have qualia is distinct from the question of whether one of them must be the unique inheritor of your STC.
Yes, you’re right. You’re describing a “branching thread of consciousness” model. Next, can there be a branching-and-merging model? Does it even make sense to ask the question?
If STC is a purely subjective experience unobservable from the outside, then we can’t really count the STCs. We may not be able to actually assert that the number of STCs at time n+1 is greater than at time n. In other words, we don’t really know if STCs can branch and/or merge even in our actual universe.
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 they have qualia is distinct from the question of whether one of them must be the unique inheritor of your STC.
Well, you can’t really. None of us can really imagine a universe. We can imagine a bundle of properties which don’t, so far as we can see, contradict each other. But the caveat “so far as we can see” is important.
Yes, you’re right. You’re describing a “branching thread of consciousness” model. Next, can there be a branching-and-merging model? Does it even make sense to ask the question?
If STC is a purely subjective experience unobservable from the outside, then we can’t really count the STCs. We may not be able to actually assert that the number of STCs at time n+1 is greater than at time n. In other words, we don’t really know if STCs can branch and/or merge even in our actual universe.