The irrationality of disgust suggests it is unreliable as a source of moral insight. There may be good arguments against gay marriage, partial-birth abortions and human cloning, but the fact that some people find such acts to be disgusting should carry no weight.

I kind of like social media, and I like hearing from people. I don't like the ugly stuff, but there are some people - smart people - who have a very different perspective, and I'll get a backlash from them. And this isn't necessarily a bad thing.

When people want to inspire you to turn against some group of people, they'll often use empathy.

I think we should really discourage this sort of empathic engagement when it comes to making moral decisions. I think we should focus on something like compassion, on getting people to care more for others without putting ourselves in their shoes.

Because of empathy, we care more for, and devote far more resources to, someone who is familiar, from our country or our group, than a stranger.

I think we're going to care more about Americans than Africans. I don't think that's ever going to go away, and I don't think it's ever going to go away that people care more about their families than strangers, and their communities over other communities. But I think it would transform the world in such a good way if we could just acknowledge, at least intellectually, that an African life and an American life are the same.

And empathy is narrow; it connects us to particular individuals, real or imagined, but is insensitive to numerical differences and statistical data.