I must say that from every point of view that was a disappointment. I mean, first of all, the fact that he wasn't willing to listen, that was a shock. But in addition to that, that he wasn't really a good leader, and I'd been told so much about how wonderful he was at Los Alamos. I mean at Los Alamos he was like the great conductor conducting this big orchestra of people and that they all felt so intensely grateful to him for leading the operation so well. And I'd expected something like that at Princeton, but there was nothing of that at all. He hadn't any kind of detailed interest in what people were doing, and he was remote, and the real problem was he was spending about two thirds of the time in Washington and he was so absorbed in public affairs. So for him - I mean he liked to come to the seminars and show off how much he knew about things that he didn't really know about. But he never gave us really any sort of leadership. So that was a big disappointment. And then of course thirdly the fact that the things that he actually had done himself, the best contributions he made to physics, were the description of black holes, the work in gravitation which he did just before the war with Snyder and Volkoff; two papers, one on neutron stars and one on the black holes, which I considered really the most substantial contributions to physics that he had ever made. And I was deeply interested in black holes, in fact, at that time, and he wasn't. That came as a great surprise, that he refused to talk about black holes. He thought of that as something any graduate student could have done and it wasn't really worthy of him. I don't know why, but he was basically not interested. I found that very strange. Of course it was even more true of Einstein. Einstein was actively hostile to black holes. It's very hard to understand from our present view point, black holes being now by the far the most profound consequence of general relativity.

But for... I mean for Einstein it's understandable because he wanted a theory free of singularities, right?

Yes, but why be so dogmatic? I mean there was solid evidence that black holes exist and he wasn't able - he wasn't even willing - to consider it as a question.

And during your stay at the Institute you actually had the occasion to be able to talk to him?

Not to Einstein, but to Oppenheimer.

You never spoke to Einstein?

Never spoke to Einstein, but I did talk to Oppenheimer, and that was also very disappointing. So, I think from every point of view he was a disappointment. I only got to like him a bit later on his life when he'd been battered and when he was dying especially, I mean, then he became quite different.