PS: Hang on a minute, we are talking here about a factual question, it's not a question of the value of life, it's a question about the strength of the preference for going on living. The Nazis may not have really thought about this at all, but if they do think about how important it is to the Jew that the Jew wants to go on living and how important it is to the Nazi that they don't want there to be Jews in the world, I think that a Nazi who considers the issue cannot fail to recognise that this is more important to the Jew. The problem is that the Nazis were basically saying that Jewish preferences don't count because they are Jews, and that's of course what I am rejecting.

NB: You just shifted from a description of what Nazis do want to what Nazis ought to want.

PS: No, no, no.

NB: You shifted from an "is" to an "ought". I don't want to be pedantic, but it seems as if you are trying to describe the strength of a Nazi's attachment to cleansing the world of Jews and compare that to the strength of the Jewish victims' desire to live. I have no idea how on earth you can determine which is the stronger. If you want to make a judgment that the Nazi desire to cleanse the world of Jews is wrong and the Jews' desire to live is right, then I'm with you there, but that has to be in terms of some appeal to what's objectively valuable in the world and what's immoral. I know that you want to avoid that but I don't think you have succeeded in doing it.

PS: I'm not sure why I haven't succeeded in doing that. I agree it could be done in the way that you are suggesting if you were to have this independent standard of objective values, which you then need to ground in some way. What I'm suggesting is that it's enough to try to put yourself in the position of both the Jewish person who's going to be killed, and then to put yourself in the position of the Nazi and see whether they are comparable desires.

One way of putting it would be to say if you were the Nazi, to think about your own life, and think about whether if you had the choice of saying, "So the Jew will be killed but you will also be killed," will you accept that choice? Or alternatively saying, "The Jew will live and you will live," then I'm sure that 99.9 per cent of Nazis would have said, "Oh well, if that's the choice, then yes, I will let the Jew live." That is a way of indicating that for the Nazi himself the desire to live is more important than the desire to satisfy his racist or ideological preference that there not be Jews in the world.

DJ: Peter, one of your most controversial positions is your support for infanticide in certain and very limited circumstances. How does your argument work there, when this is clearly something which deeply offends the sensibilities of very large numbers of people? Why would the preference of, let us say, a couple who don't feel able to look after a Down's syndrome child take precedence over the general disapproval of infanticide?

PS: Well, it might not. It depends on the circumstances and it might depend indeed upon the society and the culture in which you are. In this case, it's not only the preferences that the couple have now, it's the preferences that they will have throughout their lifetime with the child. Now you mentioned Down's syndrome, which is a case where the child can have, I think, an enjoyable life, and also a case where you may be able to find that if that particular couple does not feel able to bring up the child then another couple may well feel able to do so. In that case, I would not support infanticide of someone with Down's syndrome.