For an animal, sex is just sex—a physical thing. It is not a route to something else. Man is the only one who does not know how much sex he wants. For an animal, sex is the thing and the end of the thing. For man, sex is not merely a thing—for man, sex is a medium that will lead to a great joy. So, man does so much in order to get more sex. And man rapes; no animal rapes really. And man masturbates; animals don’t quite feel that need.