It also worries me quite a lot that eliezer's post is entirely symmetric under the action of replacing his chosen notions with the pebble-sorter's notions. This property qualifies as "moral relativism" in my book, though there is no point in arguing about the meanings of words.

My posts on universal instrumental values are not symmetric under replacing UIVs with some other set of goals that an agent might have. UIVs are the unique set of values X such that in order to achieve any other value Y, you first have to do X. Maybe I find this satisfying because I have always been more at home with category theory than logic; I have defined a set of values by requiring them to satisfy a universal property.

It also worries me quite a lot that eliezer's post is entirely symmetric under the action of replacing his chosen notions with the pebble-sorter's notions. This property qualifies as "moral relativism" in my book, though there is no point in arguing about the meanings of words.

My posts on universal instrumental values are not symmetric under replacing UIVs with some other set of goals that an agent might have. UIVs are the unique set of values X such that in order to achieve any other value Y, you first have to do X. Maybe I find this satisfying because I have always been more at home with category theory than logic; I have defined a set of values by requiring them to satisfy a universal property.

I think that your use of the word arbitrary differs from mine. My mind labels statements such as "we should preserve human laughter for ever and ever" with the "roko-arbitrary" label. Not that I don't enjoy laughter, but there are plenty of things that I presently enjoy that, if I had the choice, I would modify myself to enjoy less. Activities such as enjoying making fun of other people, eating sweet foods, etc. It strikes me that the dividing line between "things I like but wish I didn't like" and "things I like and want to keep liking" should be made in some non-roko-arbitrary way. One might incorporate my position with eliezer's by saying that my concept of "rightness" relies heavily on my concept of arbitrariness, and that my concept of arbitrariness is clearly different to eliezer's.

virge makes a very good point here. The human mind is probably rather flexible in terms of it's ethical views; I suspect that Eli is overplaying our psychological unity.