It's always difficult to know what you, what... what actually makes you decide to go anywhere, and the reasons you give... give for yourself are not necessarily the reasons that actually work. I think the… on the one hand I'd been to Princeton a lot, in the past, you know, I went there first, when I first… after my PhD; I'd been on two subsequent visits for a term, and you know, there's no question Princeton was for all a 'Mecca' of mathematicians. All the big shots were there, it was… so in some ways it was the natural thing to go.

I'd spent a year visiting before, that was in ‘67 which was actually when they, sort of invited me to take the job. I said, ‘I'm not going to make up my mind while I'm here, I'm going to go back and, wait till I get back to England and decide’. And I think the other... the other factor was… some aspects of things in Oxford, sort of, you know, I didn't like very much. Well there were two things. One was that the, the general university set up and… there was a lot of resistance to change and getting things done and bureaucracy and… and conservatism. And there was the… there was the Franks Commission which was on when I first went there and it had expectations of big reforms, but most of those reforms were rather, you know, modified in practice and didn't actually… so I was a bit disillusioned that Oxford wasn't going to change in the way I thought it ought to change. And secondly, I got to the point where until that stage I'd been a, sort of, young chap and there were always, you know, you had… you had older people around from who you... you learnt things and you know, worked in an environment.

I got to the point where I was at Oxford, there was nobody else, nobody from whom I could learn anything, you know, I'd got to the end… end of the road as far as that was concerned. And I said, well, you know so, if I went to Princeton there would be other people from whom I could actually benefit from… who knew more than me, and therefore I was going to the place where I thought I would continue to be a kind of student in that sense. At least that was… those were the kinds of reasons that I gave to myself, but I suppose just the attraction, you think it's a sort of a step up in the world, going to the institute at Princeton. And of course, you know, it was a research job, I didn't have to do teaching. In Oxford as a professor you don't have to do much teaching, but you had to give courses and involve yourself. So that a kind of factor… and of course the institute has a very relaxed timetable; every April you could come away, end of the year I could come back and I did spend the rest of the year in Oxford. So you know, it wasn't total… you didn't separate yourself totally. I was back for the term and part of the summer.

And of course the institute at Princeton had the attraction that there was a lot of money, you could invite lots of people, you know – you came and worked with me at the institute, I could provide assistance. So it gave you a lot of possibilities for operating on a bigger scale and all the visitors there were obviously a benefit. So there were lots of reasons which, you know… other people have gone to Princeton presumably for those sort of reasons, but they don't always stay.

[Q] No, neither did you.

Some people go there for a while and come back. I arrived, for example, just as Hörmander was leaving. He, he'd been... he’d been from Sweden after getting his Fields Medal. He'd gone to the institute. I think he spent about three years and just as I was going there he was just deciding to go back to Sweden. So, it's a sort of… not an unusual path to follow.