RT: The very fact that we have laws of war —  OK, we flout them, but the fact that we are aware that we're flouting them and try to conceal the fact says something about our moral progress. Roger, is your philosophical conservatism anchored in your pessimistic view of our species-being? Do you think that there are permanent flaws in the human race?

RS: I'm sure I'm open to correction in this respect but I see much of the progress that we have made as being the by-product of prosperity. We are not living in the state of need that tempts us to those evil acts that our ancestors were constantly tempted to: to steal, to murder, to become a highwayman, etc. Defoe, in Moll Flanders, wonderfully describes somebody in that condition of need who is clearly a warm and compassionate person but who has to incorporate into her world the morality of theft. This is her way of survival.  

But it is interesting that the first big age of technological and economic progress — the 20th century — was the age of the great exterminations too. So I hesitate to go along with the idea of moral progress entirely and I also think the rule of niceness has a downside in human relations: the loss of loyalties. You see it in the collapse of marriage, the betrayal of children, the escaping from any long-term commitments. Nice people do it but this might mean that the nice are the enemy of the good.

RT: I agree that the instinct of niceness may mean that one avoids the moral challenges that justify some conflicts. And I agree with you that often we are able to behave better than our predecessors because it costs us less than it might have cost them. To behave well in the Pleistocene era you had to be a saint and you probably wouldn't survive. But is denying moral progress true to history? Often, new moral sensibilities have emerged, such as those that prompted the abolition of slavery. Slavery had to be seen as wrong first.

RS: Implementation is one thing but acknowledgment of the truth is another. Slavery is not acknowledged in the Roman natural law and Isidore of Seville made it clear that under Christian jurisdiction there could not be ownership of another person. English common law abolished it before parliament set about imposing abolition upon those barbarians across the Channel. Again, prosperity made it possible to implement the abolition of slavery. It could be that people have always known it to be wrong, but found no easy way to bring it to an end. Aristotle had to lean over backwards to justify it.

RT: What you're saying is that if Aristotle had had a washing machine then he wouldn't have defended domestic slavery?

RS: It's quite possible that he wouldn't. 

RT: You have a profound, and often all too justified, suspicion of human beings and you believe that the claims that we are "born free" and "born good" are nonsense. The record of the 20th century, when proportionally humans killed more people relative to the overall population than at any other time in history (Niall Ferguson did the sums), speaks for itself. So what looks like moral progress may just be down to the fact that the cost of being a nice person now is cheaper than it was when we didn't have science-based technologies to make life easier.