It is true that raids and battles killed a tiny percentage of the numbers that die in modern warfare. But in tribal violence, the clashes are more frequent, the percentage of men in the population who fight is greater, and the rates of death per battle are higher.

By exploring the political and moral colorings of discoveries about what makes us tick, we can have a more honest science and a less fearful intellectual milieu.

Morality, then, is not a set of arbitrary regulations dictated by a vengeful deity and written down in a book; nor is it the custom of a particular culture or tribe. It is a consequence of the interchangeability of perspectives and the opportunity the world provides for positive-sum games.

Pre-state societies were far more violent than our own.

I don't consider myself to be that radical a thinker.

We will never have a perfect world, but it's not romantic or naive to work toward a better one.

I have never been a fan of science fiction. For me, fiction has to explore the combinatorial possibilities of people interacting under the constraints imposed by our biology and history. When an author is free to suspend the constraints, it's tennis without a net.