Medawar was actually... he was a new boy at the same time as me. I mean, Watson retired the year I graduated and became a graduate student, and Medawar became Professor of Zoology the year I became a graduate student. He was an immunologist. And to be honest, I'd never heard of him when he was appointed. I remember learning that this person called PB Medawar was going to be our new Professor of Zoology, and I was a first year graduate student with Haldane at that stage. And I remember asking Haldane one evening about, you know, what sort of chap is this Medawar.  To which Haldane replied, 'He smiles and smiles and is a villain.' And if you knew Peter Medawar, it was a perfect description, except, of course, that Peter was a great scientist with a passion for the truth. But he... it wasn't fair really, he was not only incredibly intelligent and skilful manually, all the gifts you need to be a great scientist. He was also extraordinarily handsome, I mean, he really was very handsome indeed. He had a beautiful wife, charming children, one just really felt that, you know, too much had been given to one man.

[Q] Niko Tinbergen described him as touched by the gods.

Yes, there was an element, and, of course, as you know, the gods got him, he had a terrible stroke. But Peter was, this curious amalgam, of on the one hand, a man so charming. Another - I've quoted one piece of Shakespeare, let me quote another one: 'He would have men about him that are fat, sleek-headed men, and such that sleep at nights.' He didn't like rows, he liked courtesy, he liked comfort around him. But this is giving a totally false impression of the real Medawar. The real Medawar was a man passionate for the truth... and deeply critical of fudge, of obscurantism, of muddle. He was a lovely man, I mean, I... I want to make it clear that I loved him, and yet, there was a part of Peter, this smoothness, this charm, which one felt was unfair, almost, you know.

I can remember him - my wife and I used to play bridge with Peter every Saturday night, not with Peter and his wife, because his wife didn't like bridge, but with Peter and his mother, and you only had to meet his mother to know where the IQ had come from, she was a very smart old lady. Anyway, not that this has got anything to do with science, but I remember Peter ringing me up one Friday, just checking that Sheila and I were OK for the bridge. I'd just been reading The Times, which we took in those days, and on the front page of The Times was a new honours list. Peter was going to become Sir Peter Medawar. It was breakfast time, I wasn't really awake, and the phone rang and Peter's voice was there, and I said, 'Peter, there's dreadful news in The Times this morning, have you seen it?' To which he replied, 'John, I knew you'd feel like that.' So, you know, there was... Peter wanted to become Sir Peter Medawar. It's ridiculous, how can the crew that give out honours honour a man like that? I mean, it's absurd. I mean, he had honour, but he didn't have to be honoured by that crew. I felt sad about it, and he knew I'd feel sad about it, but we were... the thing I learned from Medawar, scientifically, apart from the importance of clarity and rigour, was that scientific issues ultimately have to be settled by observation or experiment. If there is no observation or experiment that can settle a scientific question, it's not a scientific question. I mean, leave it to the philosophers and let them waste time on it. Ultimately, there has to be a scientific... there has to be an experimental or observational way of doing it. And Peter was very happy, he'd argue for hours, but once one had narrowed a question down to some question of fact that could in principle be done, he didn't really want to discuss it anymore until somebody had done it. And he, of course, had a genius for deciding and designing the experiment that would settle it.