(c. 469BC - 399BC)
"It is better to be a human being dissatisfied than a pig satisfied; better to be Socrates dissatisfied than a fool satisfied. And if the fool, or the pig, are a different opinion, it is because they only know their own side of the question."
John Stuart Mill, Utilitarianism (1863)
A Happy Pig
Haydn and the Oyster
Utilitarianism by J.S. Mill
Jeremy Bentham on Animal Suffering