I was in Berkeley for a semester, and I was teaching a group of graduate students a course in theoretical biology. It was a lovely teaching job, I know many of them still and they were great students, lovely. And while I was running this seminar, Kimura came through and gave a seminar. And I asked him if he would spend the evening with my class, and just talk, we would talk with him and so on. And it was a fascinating evening, I'd love to have it on tape, except you should never tape something without the person present knowing, I mean, I wouldn't have dreamed of taping it, but all the same, I'd love to have a tape of that evening. Because these kids were very nice and, on the whole, very bright, but they were also, being Americans, rather brash and they... they were quite willing to press this great man and not let him get away from it, and so he was really pushed into discussing issues which are normally very hard for him. And the one thing I remember of the evening, actually what he said, was actually in answer to a question I asked him. I said, 'Look, Motoo, there are really two parts to the neutral theory. The neutral theory first of all says that selective... not selective, that changes in molecules that occur, or mostly occur, because they're selectively neutral. And the other one says that the... if you look at the standing crop of variation at any one time, most of that variation is neutral. Now, it's logically possible that one of those statements is right and the other one is wrong. How would you feel if it turned out that you were right about substitution but wrong about polymorphism?' And he said, 'It is logically possible, but it would be very inelegant.' And I think this tells you about Kimura's mind. It was a mind which liked elegance. It was a very powerful mind but it was a mind which was seeking for simplicity.