I wanted my readers to realize that man alone of all the creatures that inhabit the earth or the waters below or the air above takes life wantonly; he is the only creature that derives pleasure from inflicting pain on other creatures, even his own kind. Jealousy, greed, hate, spitefulness are more fully developed in man than in the lower orders. These are axiomatic truths that require no demonstration.
~ The Tarzan Theme, Edgar Rice Burroughs.
