Bush sees the evil as out there in the wider world, residing in people who 'hate freedom'. Look at his immediate response to the pictures of prisoner abuse; this is not what Americans do, these are not our values.

If it is in our power to prevent something bad from happening, without thereby sacrificing anything of comparable moral importance, we ought, morally, to do it.

There is an obvious evolutionary explanation for the scarcity of altruistic saints: Without a strong predilection for their own interests, our ancestors would have been unlikely to survive, reproduce, and give their own offspring a chance of doing the same. Now conditions have changed and for most of us, surviving and reproducing isn't such a struggle but we still carry the genes of our ancestors and they influence - not determine, but influence - our behavior.

Were we incapable of empathy – of putting ourselves in the position of others and seeing that their suffering is like our own – then ethical reasoning would lead nowhere. If emotion without reason is blind, then reason without emotion is impotent.

Charitable giving is a huge sector in the United States. It amounts to $350 billion a year. And yet, I can't help feeling that a lot of that is wasted because people have not been thinking about how to do it as effectively as possible.

Of course, infanticide needs to be strictly legally controlled and rare - but it should not be ruled out, any more than abortion.

I believe that in this new world that we live in, we often have a responsibility, you know, to actually go beyond the thou shalt nots - that is, the not harming others - and say we can help others and we should be helping others.