However, in Many-Worlds Interpretation (MWI), I split my measure between multiple variants, which will be functionally different enough to regard my future selves as different minds. Thus, the act of choice itself lessens my measure by a factor of approximately 10. If I care about this, I’m caring about something unobservable.
If we’re going to make sense of living in a branching multiverse, then we’ll need to adopt a more fluid concept of personal identity.
Scenario: I take a sleeping pill that will make me fall asleep in 30 minutes. However, the person who wakes up in my bed the next morning will have no memory of that 30-minute period; his last memory will be of taking the pill.
If I imagine myself experiencing that 30-minute interval, intuitively it doesn’t at all feel like “I have less than 30 minutes to live.” Instead, it feels like I’d be pretty much indifferent to being in this situation—maybe the person who wakes up tomorrow is not “me” in the artificial sense of having a forward-looking continuity of consciousness with my current self, but that’s not really what I care about anyway. He is similar enough to current-me that I value his existence and well-being to nearly the same degree as I do my own; in other words, he “is me” for all practical purposes.
The same is true of the versions of me in nearby world branches. I can no longer observe or influence them, but they still “matter” to me. Of course, the degree of self-identification will decrease over time as they diverge, but then again, so does my degree of identification with the “me” many decades in the future, even assuming a single timeline.
If we’re going to make sense of living in a branching multiverse, then we’ll need to adopt a more fluid concept of personal identity.
Scenario: I take a sleeping pill that will make me fall asleep in 30 minutes. However, the person who wakes up in my bed the next morning will have no memory of that 30-minute period; his last memory will be of taking the pill.
If I imagine myself experiencing that 30-minute interval, intuitively it doesn’t at all feel like “I have less than 30 minutes to live.” Instead, it feels like I’d be pretty much indifferent to being in this situation—maybe the person who wakes up tomorrow is not “me” in the artificial sense of having a forward-looking continuity of consciousness with my current self, but that’s not really what I care about anyway. He is similar enough to current-me that I value his existence and well-being to nearly the same degree as I do my own; in other words, he “is me” for all practical purposes.
The same is true of the versions of me in nearby world branches. I can no longer observe or influence them, but they still “matter” to me. Of course, the degree of self-identification will decrease over time as they diverge, but then again, so does my degree of identification with the “me” many decades in the future, even assuming a single timeline.
A sad thing is that most of life moments are like this 30-minutes intervals—we forget most life events, they are like dead ends.
More generally, type-copies of me still matter for me.