For most versions of selfishness, if you’re duplicated, then the two copies will have divergent preferences. However, if one of the copies is destroyed during duplication, this just counts as transportation. So the previous self values either future copies if only one exists. Therefore it seems incoherent for the previous self not to value both future copies if both exist, and hence for the two future copies not to value each other.
(btw, the logical conclusion is that the two copies have the same preferences, not that the two agents must value each other—it’s possible that copy A only cares about themselves, and copy B only cares about copy A).
Interesting! Can you explain that in text?
For most versions of selfishness, if you’re duplicated, then the two copies will have divergent preferences. However, if one of the copies is destroyed during duplication, this just counts as transportation. So the previous self values either future copies if only one exists. Therefore it seems incoherent for the previous self not to value both future copies if both exist, and hence for the two future copies not to value each other.
(btw, the logical conclusion is that the two copies have the same preferences, not that the two agents must value each other—it’s possible that copy A only cares about themselves, and copy B only cares about copy A).