> Sentience DOES make a difference. You dont frown on your cat for hunting mice, but on your dog for doing it with children.

That's at least partly due to speciesm. How many people have gone on crusades to stop leopards from eating chimpanzees? For that matter, how many people devote their lives to stopping other *humans* from eating chimpanzees?

As for cannibalism, it seems to me that its role in Eliezer's story is to trigger a purely illogical revulsion in the humans who antropomorphise the aliens.

Imagine two completely different alien species living in one (technological) society, where each eats and "winnows" the other's children. This is the natural, evolved behavior of both species, just as big cats eat apes and (human) apes eat antelopes.

No cannibalism takes place, but the same amount of death and suffering is present as in Eliezer's scenario. Should we be less or more revolted at this? Which scenario has the greater moral weight? Should we say the two-species configuration is morally superior because they've developed a peaceful, stable society with two intelligent species coexisting instead of warring and hunting each other?