[anigbrowl]

I personally think that sentience (and thus maximal interpersonal utility) is only possible to the extent that it's possible to anticipate someone else's desire by modeling it in terms of one's own. The degree to which I can imagine what you want depends on the ability to imagine myself in your position, and once that happens there's always the possibility that I might find occupying your position to be more desirable than remaining in my own.