Well, in general, you know, the experimentalists in biology, I think, occupy the more important place because there are very few areas in biology where you can do what you could call steady theoretical work. Some of the work, the mathematical work in… to do with evolution would be a case where you can… the theorists can make important contributions and some of the present work being done on how nerve cells behave, a single nerve cell with all the things coming in, that can be done. But the other sort… there is another sort of theory which consists of not so much doing computations to test out a particular idea but having, sort of, general ideas, as in the case of DNA. We had the general ideas, we then had to build the structure and show that it actually could be built, but the important thing was having the idea of what we were trying to build and although there is a certain scope for… for people doing that, usually it’s better if that’s combined with doing experiments. And if I were younger I think I would try to do more of this… some sort of experiments in some area of brain research, but the ones that particularly interested me… interest me are very demanding and time consuming and take rather a long apprenticeship, so I don’t do them. So, I think you… what is important really is that different experimentalists should talk to each other and exchange ideas and that is probably as important. After all, the theory of natural selection was an idea, you see, when you think about it, and sometimes ideas come out of the experiments and sometimes the ideas come first and then… and then the experiments are designed round them and course there’s a constant flux to and fro in most cases.

[Q] I mean, is it temperament which takes… or accident which takes a scientist in one direction or another?

Yes, well it’s not so much temperament, it’s also ability. Some people are very good at doing experiments and… doing experiments is not easy because first of all you have to be fairly meticulous and not too sloppy and do things in the right sort of way, and then secondly you have to have a sort of feeling, a sort of green fingers as when it doesn’t work as to what it is that you can make it to work, and that is very difficult to teach and… some people seem to have the ability to do that and some people don’t – they just get bogged down in the details.

[Q] And how about you?

Well, I’m not sure I’m so good at that. I mean the only good experiments I’ve done, when we blundered on, essentially, were doing… I was doing some phage genetics, genetics on bacteria phage. I was doing some bacteria phage genetics and found an odd phenomenon and then did explore it and then I’d… and… but the experiments were relatively easy to do and could be done rapidly and… and you could get results very quickly. And there was something to think about because it turned out you could… it was a formal scheme that you could put them into which wasn’t at all obvious and was novel and was not unimportant. But I don’t think I was particularly good at biochemical experiments although, again, it may be if I’d been apprenticed to somebody who was doing biochemical experiments and had stuck at it, I would have acquired the… the expertise and… and could then could use my intellectual ability together with the experimental know-how.