The Commonwealth Fellowship, of course, wasn't intended as a PhD course. It was intended just to have two years in America, and in England the PhD system hadn't yet really got its grip on the academic community, so I didn't need a PhD if I stayed in England, so I didn't bother about that. I think if I had stayed at Cornell I couldn't have got the PhD in two years anyway; there were some rules that didn't allow that. So it didn't come into question. So all I did was... in fact, I was nominally a student for a Master's degree which I never took. And then, in fact then, sometime in Spring of '48, Bethe and Oppenheimer got together and arranged that I would spend the second year at the Institute [for Advanced Study] in Princeton instead of Cornell, and I don't know exactly why, or who took the initiative, but in any case, I think Bethe thought it would be quite a good idea for me to get exposed to Oppenheimer and the various other people who were around here. So, anyway, he encouraged me to apply for the Institute and so I did. And so I was set to come to the Institute in the fall of 1948, just to get a fresh look at a different collection of people. And it was of course, for me, it was not such a difficult choice because I was mostly just interested in sightseeing and everybody had heard of Oppenheimer and so it was an opportunity I didn't want to miss, actually to work with Oppenheimer, even though I might have learned more from Feynman if I'd stayed at Cornell.