Ah, that makes sense. (I was wondering why nyan_sandwich's comment was being upvoted so much when I already mentioned selfish values in the OP.) To be clear, I'm using "value differences" to mean both selfish-but-symmetric values and "more fundamental difference such as sacredness vs avoiding harm". (ETA: It makes sense to me because I tend to think of values in terms of utility functions that take world states as inputs.) I guess we could argue about which kind of difference is more important but that doesn't seem relevant to the point I wanted to make.