Our patterns of aggression are little changed from those that we see in chimpanzees. But while chimpanzees have, to some extent, an awareness of the pain which they may inflict on their victims, only we, I believe, are capable of real cruelty—the deliberate infliction of physical or mental pain on living creatures despite, or even because of, our precise understanding of the suffering involved. Only we are capable of torture. Only we, surely, are capable of evil.

