Michael Frayn. I'm extremely overawed at speaking in this distinguished institute. The last time I spoke in a scientific laboratory was in Tasmania. (laughter) As I began to speak, God, possibly objecting to a nonscientist speaking in a laboratory, sent an enormous electrical storm, and there was colossal thunder and lightning and it became extremely difficult to make myself heard over the noise. So I went round to the front of the demonstration desk and perched on it in a most informal way in order to get closer to the audience and make myself more audible. The storm got so bad that it began to affect the lighting in the room. And the lights began to go on and off (with quantum randomness) all over the room which made it of course even more difficult to communicate. At the end of the lecture, which was really quite a hair-raising experience, the man who was organizing it – as it were the Finn Aaserud of Tasmania (laughter) – said, "That was most enjoyable; I'm very sorry about the electrical storm." I said, "The worst thing of all was when it began to affect the lighting in the room." He said, "Well, actually, that wasn't the electrical storm, that was because you were sitting on the bank of lighting switches." (laughter)

I'm even more overawed at being in this particular institute, because of its reputation, and because of my very first contact with it when I was researching my play. I simply phoned from England, not having the faintest idea who was going to be here, to make a contact, and asked if I could come and have a look at it, and use the archive. When the voice answered in Danish, I – in that hopeless way that English speakers, I'm afraid, do – raised my voice and said very slowly, "Do you speak English?" (laughter) The voice at the other end said, "Yes of course. (laughter) But if it's an archival matter you will have to call back tomorrow when the archivist is here because I'm merely the security guard." (laughter) So I began feeling extremely humble about the whole thing.

Finn asked me why I had written this play about real people. And I have to say, it's not quite like that. As a writer one doesn't really choose one's stories; stories choose one. The story comes into one's head, and seizes one's imagination, for some reason. Then later on, possibly you begin to see why it has seized your imagination; you begin to see the implications of the story. This all began for me – I should say that I have no scientific background at all, I was trained as a philosopher, but of course anyone interested in philosophy has to be interested in the work that was done here in the 1920s because it has such huge philosophical resonances – when Thomas Powers published his book, "Heisenberg's War." I read it and for the first time came across the story of Heisenberg's visit to Niels Bohr in Copenhagen in 1941, with all the attendant difficulties of, first of all, knowing what was said between them, and secondly, knowing what Heisenberg's intentions were in undertaking the trip. It seemed to me that this crystallizedized – offered a parallel with – the kind of difficulties (the physical difficulties in being absolutely clear about what is going on inside an atom) that Bohr and Heisenberg had explored in the twenties. It thus crystallized a lot of the epistemological difficulties I'd been thinking about as a philosopher for many years. So that's why I did it about real people.

This of course has its dangers, and I was particularly nervous about coming to see the production here in Copenhagen, where a lot of the central events in the play took place – where two of the central characters, at any rate, are still extremely well known and alive in people's memory. A lot of events in the play must evoke often painful echoes in people's minds. I was immensely relieved to find this most wonderful production that Peter Langdal has done at the Betty Nansen Theatre. I really do think it's one of the finest productions I've ever had of any of my plays anywhere in the world. I was intensely moved by it and intensely grateful for it. Whatever the shortcomings of my play, it could not have been put in front of you in Copenhagen in a better form than it has been.

So that's why it's about real people. You might say, well, if it's about real people, why have I chosen to do it in a fictitious way. Well, for several reasons. First of all, fiction offers the possibility of play, and play is very important. I think it's particularly important if you're looking at quantum mechanics where the whole possibility of arriving at any understanding of quantum mechanics is so difficult. And where it does seem to involve, particularly in the modern interpretation of quantum mechanics, the possibility of different interpretations, different worlds, or different events co-existing.

I've been reading recently Murray Gell-Mann with his criticisms of the Copenhagen interpretation and I have to say, in parenthesis, that I'm slightly surprised by his view that the Copenhagen interpretation is anthropocentric in a way that his view is not. I think it's absolutely true that Bohr's view, the Copenhagen interpretation, was anthropocentric, and it seems to me one of its great glories. If you read Gell-Mann he goes on to develop a view of quantum mechanics derived from Everett which depends on the idea of histories and narratives. How that is not anthropocentric I can't imagine. Histories and narratives don't exist out there in the world. Histories and narratives are told, by people. They are centered in the human consciousness just as much as observation was in Bohr's view.

And there is of course a parallel between what Gell-Mann is suggesting of different narratives and what we writers of fiction do all the time. There's a spectacularly brilliant German film showing at the moment called "Lola rennt" in German and "Run Lola Run" in English, which seems to me an exposition of Gell-Mann's view of quantum mechanics. It shows the possibility of different narratives co-existing with branching points where one narrative can branch into another. And that is very much a form of play.

OK. So if I was going to do it about real people, as fiction, why didn't I do it as a novel, since I also write novels? Well, the natural form of the novel – it doesn't have to be so – is that the narrator is all-knowing. He knows what's going on inside people's heads; possibly in the heads of all the characters, possibly in the heads of one or two of the more privileged characters, the central characters. What's at issue in this story is to find out what's happening in people's heads. If the author knows already, there is no story. The position we're in in life is that we look at each other externally, we have to work out from what people say, the way they behave, their manner of being, what their motives are, what their intentions are, what their thoughts are. And there is only one person to whose head one has what philosophers would call privileged access, and that is one's own. However, it's my contention that it is very difficult to know even about the events inside one's own head, one's own motivation, without getting a reaction from somebody else.

A lot of commentators have talked about it having a moral thesis about whether scientists should work on military programs or not – that's really a side issue. The moral issues always finally depend on the epistemological one, on the judgment of other people's motives, because if you can't have any knowledge of other people's motives, it's very difficult to come to any objective moral judgment of their behavior. As Heisenberg says in the play, if we have to judge people's behavior entirely by external effects, as Heisenberg decided we have to judge the behavior of particles, we would be living in an extremely strange world. And it would simply be whether actions happened to turn out well that gave us the basis for our moral judgment. This isn't so. We plainly do attempt to assess people's intentions. That goes very deep in our reading of other people.

So the play, the theatre, is a very good format for doing that. The play is about confrontations of people who look at each other and try to work out from external behavior what is going on. I think once again this possibility of the drama does offer some parallels with the world of physics as it has become. It has enormously changed in this century. There is now some coming together of the worlds of art, of story telling, and of physics. That's all I want to say in my introductory remarks. (applause)