I have never quite understood why the utility monster thought experiment was supposed to be a “checkmate, utilitarians!”
The utility monster, for those of you who don’t know, is a hypothetical beast who derives much more utility from everything than anyone else. He finds cookies, tea, music, and so on a thousand times more pleasurable than anyone else; conversely, he finds even a pinprick a thousand times more painful. Therefore, the utility monster outweighs everyone else and you should sacrifice utility for him.
Now, pigs have preferences over states of the world, can feel pain and pleasure, and can probably even feel my handwavey concept of eudaimonia. Therefore, under most formulations of utilitarianism, pigs matter ethically. However, most people– even most animal-rights advocates– agree that humans matter more than pigs: if you have a choice of giving a delicious meal to a pig or a delicious meal to a human, you should probably not give it to the pig.
(This, of course, does not justify torturing a pig to feed a delicious meal to a human.)
If you ask people why this is, you’ll get a lot of answers like “humans are smart, pigs are dumb” or “humans are conscious, pigs aren’t”, which cache out as: humans feel pain and pleasure more intensely, we are more capable of eudaimonia, we hold stronger preferences; that is, humans are utility monsters.