DJ: What was his relationship with Hitler? Did he get money from Germany?

NM: He never got money from Germany. When I questioned Diana about money, first of all she said she didn't know anything about the Mussolini money, which was rubbish, of course she did. And then I said, "Did you ever get any money from Germany?" She said, "Oh well Nicky, of course I tried, but Goebbels was terribly mean." And I said, "What do you mean, terribly mean?", and she said, "Well, he would never give me anything, so I just used to come home with a couple of hundred pound notes."

RC: Hitler probably talked to Diana more about politics than any other woman.

NM: Unity met Hitler in the famous meeting in the café when she was rolling her eyes in the corner, and Hitler asked her over to his table and asked her who she was. Unity was a sort of groupie, she was an absurd girl. Diana was an infinitely more intelligent woman than Unity. So in 1938, my father was short of money, she went over to try and negotiate, and when Hitler landed in Berlin — he spent most of his time in Berchtesgaden or Munich — in the evening, he used to send for Diana. He was exhausting. He was an insomniac, he never went to sleep. When people got totally exhausted and dropped off at midnight, then he'd send for Diana who would come over and stay until 4 o'clock in the morning. 

When one asked Diana, "Why did you like Hitler?", she said it was because he was so frightfully funny. He used to make the most wonderful jokes, he used to make one laugh. And you know what the Mitfords think about laughter. She said she was freaked with laughter. I said, "What did you talk about? Did you talk about politics?" And she said he just wanted to know all the London gossip, about the Duke of Windsor and Mrs Simpson and so on. And then he used to tell frightfully funny stories. He was a wonderful mimic — he used to mimic Mussolini and Neville Chamberlain. 

This is one of my favourite stories: when I was going through my father's papers I found a letter from Unity to Diana, written in 1936 from Berchtesgaden, saying, "Darling Diana, you really should have been here last night. The Führer kept us all in stitches for hours, imitating a woman trying on hats." No one can believe that, but I can believe it. 

I can't think what else the Mitfords would have done with him. Diana and Hitler wouldn't have talked about politics. It wouldn't have interested him, it wouldn't have interested her. She would have talked about politics with someone else, but it wasn't really her thing. Her speciality was making Mitford jokes.

DJ: It's interesting, Nick, how in all your books, particularly your recent books, God comes into them: God's Hazard and The Presence of Infinity. So you clearly do feel you need to talk about this and think about it. Whereas Raymond, you're quite content to be a confirmed atheist. You don't miss God.

NM: Raymond and I used to agree about everything, but then we've all got a bit old. The only thing we haven't agreed on is God, and neither of us knows what we mean by God. 

RC: What do you mean to say? I'm a committed atheist, for God's sake! 

NM: Well, it all goes beyond words. I say that I can't really put what I think into words anyway. I say that people who think that they can put God into words aren't really believing in God. They're believing in themselves. But if you really believe in God then you just have to shut up. So I shut up. And I then go on talking for two hours.