Washington, Conn.

Where does our sense of right and wrong come from? Most people think it is a gift from God, who revealed His laws and elevates us with His love. A smaller number think that we figure the rules out for ourselves, using our capacity to reason and choosing a philosophical system to live by.

Moral naturalists, on the other hand, believe that we have moral sentiments that have emerged from a long history of relationships. To learn about morality, you don’t rely upon revelation or metaphysics; you observe people as they live.

This week a group of moral naturalists gathered in Connecticut at a conference organized by the Edge Foundation. One of the participants, Marc Hauser of Harvard, began his career studying primates, and for moral naturalists the story of our morality begins back in the evolutionary past. It begins with the way insects, rats and monkeys learned to cooperate.

By the time humans came around, evolution had forged a pretty firm foundation for a moral sense. Jonathan Haidt of the University of Virginia argues that this moral sense is like our sense of taste. We have natural receptors that help us pick up sweetness and saltiness. In the same way, we have natural receptors that help us recognize fairness and cruelty. Just as a few universal tastes can grow into many different cuisines, a few moral senses can grow into many different moral cultures.