Families survive the terrible twos because toddlers aren't strong enough to kill with their hands and aren't capable of using lethal weapons.

I'm very interested in why we do good things, or bad things, and where moral judgments come from.

I think there's some evidence that we're empathic by nature. There is some evidence from studies of babies and young children that they resonate with the pain of others, and there's some work by Frans de Waal that other primates also resonate with the pain of others.

My book is going to be called Against Empathy, which may give you a feeling for where my argument is going to go. Whenever I talk about this, I have to begin in the most boring of all possible ways: by defining my terms. By "empathy," some people mean everything that is good - compassion, kindness, warmth, love, being a mensch, changing the world - and I'm for all of those things. I'm not a monster.

In my own life, I do not live like an effective altruist. An effective altruist would really disapprove of my life. I don't give enough to charity and I still have both my kidneys.

When I write I'll sometimes say things which are somewhat controversial - not because I'm seeking out controversy for its own sake, but if I don't have anything to say which is different, why am I bothering to write stuff down in the first place?

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.