The major thing that Haldane did scientifically, I suppose, has to be the work that he did, as well as, rather independently, RA Fisher and Sewell Wright, which was to show that genetics is compatible with Darwinism. It's very odd that in the period between 1900 and the 1920s, it really was felt that you either had to be a Mendelian geneticist or a Darwinian and you couldn't be both, which is absurd. But I think it required the work of people like Haldane to show that that wasn't true. And it involved elegant and simple mathematical modelling, essentially. But he went on making mathematical models through his life. And... I find it awfully difficult, you see talking about Haldane, to know which of the things I think - I thought of myself and which of the things I think and do, I am just imitating Haldane. Because when you live with somebody of that degree of intellect, it really is hard to know what is your own ideas and what is his. But he was also a very difficult person to work with. He was one of those people who liked the feeling of adrenaline circulating, I think. He enjoyed being either angry or afraid. He admits, for example, that he genuinely enjoyed being in the trenches in the First World War, because he was frightened the whole time, and somehow or other, that made him feel more alive. There are people who actually enjoy adrenaline, and Haldane was one of them, but it did make him awkward to live with. It was like living with an unexploded bomb, you never knew when it was going to go off.