I think we need both. We need religion and we need science. We need science to explain the universe and we need religion to explain the meaning of human existence. We stand to lose a great deal if we lose religious faith. We will lose our Western sense of human dignity. I think we will lose our Western sense of a free society. I think we will lose our understanding of moral responsibility. I think we will lose the concept of a sacred relationship, particularly that of marriage, and we will lose our concept of a meaningful life. I think that religious belief is fundamental to Western civilisation and we will lose the very heart of it if we lose our faith.

What I do not say is that it is impossible to be a thoroughgoing, insistent atheist. To the contrary, my doctoral supervisor, the late Sir Bernard Williams, one of the greatest philosophers of his age, was a thoroughgoing atheist, a categorical atheist, and I had enormous respect for him. However, his vision was ultimately a tragic one. He really believed that life had no meaning. I think he helped us understand what would happen to Europe if it were to lose its religious faith. In his finest book Shame and Necessity, he put forward the view that Europe today — Western civilisation today — is in the same basic state as the pre-Socratic Greeks. And he may well be right.

Last year Ferdinand Mount wrote an interesting book called Full Circle, in which he suggests that we are back in the situation of third-century BCE Greece. That makes a lot of sense to me; much of what we are hearing from philosophers and scientists today is very similar to the position of the Stoics, the Sceptics, the Cynics and the Epicureans. But that is not a happy place to be, because although people in third-century BCE Greece didn't know it — it's hard to know you're living in BC anything — they were going to be followed by second-century BCE Greece, which experienced decline, after which Greece did not survive as a living society for very long. A century later it had more or less suffered a complete political eclipse.