Morality binds people into groups. It gives us tribalism, it gives us genocide, war, and politics. But it also gives us heroism, altruism, and sainthood.

People who devote their lives to studying something often come to believe that the object of their fascination is the key to understanding everything.

Liberals are my friends, my colleagues, my social world.

Dividing into teams doesn't necessarily mean denigrating others. Studies of groupishness have generally found that groups increase in-group love far more than they increase out-group hostility.

The most powerful force ever known on this planet is human cooperation - a force for construction and destruction.

We can call this "the progress principle": Pleasure comes more from making progress toward goals than from achieving them. Shakespeare captured it perfectly: "Things won are done; joy's soul lies in the doing."

While the political right may moralize sex, the political left is doing it with food. Food is becoming extremely moralized nowadays, and a lot of it is ideas about purity, about what you're willing to touch, or put into your body.