Interesting review here of Daniel C. Russell, Happiness for Humans. An interesting passage:
Suppose that songbirds as they are presently constituted are not receptive to the beauty of their chirping, but that genetic manipulation could give them an enriched awareness of the musical features of their songs, with the result that they get much more enjoyment from their singing. Assuming that this had no ill side effects, their lives would be better — it would be better for a songbird to be a songbird than it was before. This thought experiment suggests that the appreciation of beauty would be a good thing for any creature who can be made receptive to it. So, it is not someone’s membership in the human family that makes it the case that it is good for him to appreciate beauty and bad for him to lack this receptivity. Rather, the appreciation of beauty is a good thing — good, that is, for the creature, of whatever species, who has it.
I wonder: what if, through genetic manipulation, I could be enhanced so as to view with aesthetic pleasure something truly and intrinsically ugly – that is, to incorrectly view it as beautiful. Would that be a good thing?