What set us apart from most or all of the other hominid species was our ultrasociality, our ability to be highly cooperative, even with strangers, people who are not at all related to us.

Our moral sense really evolved to bind groups together into teams that can cooperate in order to compete with other teams.

Scandal is great entertainment because it allows people to feel contempt, a moral emotion that gives feelings of moral superiority while asking nothing in return. With contempt you don't need to right the wrong (as with anger) or flee the scene (as with fear or disgust). And the best of all, contempt is made to share. Stories about the moral failings of others are among the most common kinds of gossip, they are a stable of talk radio, and they offer a ready way for people to show that they share a common moral orientation.

I think moral philosophy is speculation on how we ought to live together done by people who have very little clue how people work. So I think most moral philosophy is disconnected from the species that we happen to be. In fact, they like it that way. Many moral philosophers insist that morality grows out of our rationality, that it applies to any rational being anywhere in the universe, and that it is not based on contingent or coincidental facts about our evolution.

I think the greatest truths, the ones that you find in every culture that has any sort of history of reflection of writing, the greatest truth is that there's nothing good or bad, but thinking makes it so. That's the way Shakespeare put it. But you get basically the same idea from Buddha, from the Bhagavad Gita in India, and from the Stoics in ancient Greece and Rome.

Do people believe in human rights because such rights actually exist, like mathematical truths, sitting on a cosmic shelf next to the Pythagorean theorem just waiting to be discovered by Platonic reasoners? Or do people feel revulsion and sympathy when they read accounts of torture, and then invent a story about universal rights to help justify their feelings?

While it is useful to rebut charges and get your arguments out in circulation, you have to understand that arguments and evidence have little impact on people as long as their feelings tilt them against you.