
Alex V. answered 10/18/21
PhD student in philosophy with 7+ years of teaching experience
Mill argues that Socrates unsatisfied is better off than a pig satisfied because Socrates is capable of experiencing the higher pleasures, whereas the swine is not. A higher pleasure is one that a competent judge, having experienced both, would choose every time. So even if Socrates is at that time unsatisfied, the fact that he is capable of experiencing the higher pleasures makes the difference. Because they are higher and, Mill argues, more pleasurable in an important sense, he's better off for being able to experience them, while the pig, even if it's very happy in some mud at the moment, has no chance of experiencing those higher pleasures.
It's a... weird (and not very successful, imo) argument, but Mill uses it to defend the value of art, philosophy, etc. over drugs, sex, and rock & roll, and thus to argue that his form of Hedonism doesn't only rest on the baser pleasures and aspects of our natures.
Hope that helps!