I agree. It seems that in that situation the person would be “rational” to choose Right.
I’m still confused about the “UDT is incompatible with this kind of selfish values” part. It seems that an indexically-selfish person—after failing to make a binding commitment and seeing the bomb—could still rationally commit to UDT from that moment on, by defining the utility s.t. only copies that found themselves in that situation (i.e. those who failed to make a binding commitment and saw the bomb) matter. That utility is a function over uncentered histories of the world, and would result in UDT choosing Right.
I don’t see anything wrong with what you’re saying, but if you did that you’d end up not being an indexically selfish person anymore. You’d be selfish in a different, perhaps alien or counterintuitive way. So you might be reluctant to make that kind of commitment until you’ve thought about it for a much longer time, and UDT isn’t compatible with your values in the meantime. Also, without futuristic self-modification technologies, you are probably not able to make such a commitment truly binding even if you wanted to and you tried.
It seems that in many simple worlds (such as the Bomb world), an indexically-selfish agent with a utility function u over centered histories would prefer to commit to UDT with a utility function u′ over uncentered histories; where u′ is defined as the sum of all the “uncentered versions” of u (version i corresponds to u when the pointer is assumed to point to agent i).
Things seem to get more confusing in messy worlds in which the inability of an agent to define a utility function (over uncentered histories) that distinguishes between agent1 and agent2 does not entail that the two agents are about to make the same decision.
I agree. It seems that in that situation the person would be “rational” to choose Right.
I’m still confused about the “UDT is incompatible with this kind of selfish values” part. It seems that an indexically-selfish person—after failing to make a binding commitment and seeing the bomb—could still rationally commit to UDT from that moment on, by defining the utility s.t. only copies that found themselves in that situation (i.e. those who failed to make a binding commitment and saw the bomb) matter. That utility is a function over uncentered histories of the world, and would result in UDT choosing Right.
I don’t see anything wrong with what you’re saying, but if you did that you’d end up not being an indexically selfish person anymore. You’d be selfish in a different, perhaps alien or counterintuitive way. So you might be reluctant to make that kind of commitment until you’ve thought about it for a much longer time, and UDT isn’t compatible with your values in the meantime. Also, without futuristic self-modification technologies, you are probably not able to make such a commitment truly binding even if you wanted to and you tried.
Some tangentially related thoughts:
It seems that in many simple worlds (such as the Bomb world), an indexically-selfish agent with a utility function u over centered histories would prefer to commit to UDT with a utility function u′ over uncentered histories; where u′ is defined as the sum of all the “uncentered versions” of u (version i corresponds to u when the pointer is assumed to point to agent i).
Things seem to get more confusing in messy worlds in which the inability of an agent to define a utility function (over uncentered histories) that distinguishes between agent1 and agent2 does not entail that the two agents are about to make the same decision.