You know, if Pauling and Delbruck hadn't written a paper the replication would be best involved complementarity. And that paper was in '39. So the, so the idea had been there. So the moment you say, yeah, this has separated two strands...

[Q] What about complementarity of RNA to DNA? When did that? Because you had already written DNA RNA the protein.

No, no, I... so I think I tried to take an x-ray... I know I did, RNA x-ray photographs that spring. So I was thinking that way because, you know, protein synthesis occurred in the cytoplasm DNA in the nucleus otherwise you... something had to take it out there. So, you know, it was the simplest idea. I wouldn't have felt... there would be so many ways you could get around it, maybe there was another form of DNA, you know, you could... but it seemed to me... it made sense to always try and follow the consequences of the most obvious idea rather than to say, well, there can be 100 different possibilities. If one is... if there is no DNA in the... But, of course, there is DNA in the cytoplasm in the mitochondria but we did... but then there were little cells so the exception would prove, you know, yeah.

[Q] Can you think of another instance in history where someone would see their place in the universe instantaneously in such a dramatic way?

No. Probably the Kekule, you know, the Benzene structure. Well, you know, some... somehow you, somebody... but I, you know, when... Bohr in the simple electron orbits and so on, and then agreements with spectroscopy. I don't know the field well enough to know of... how instantaneous, but the answer had been proposed. And then we... we have complementarity, and so it wasn't novel.

[Q] No, but the knowing how important you are now going to be in history to count so quickly and so...

And also I didn't know how, but...

[Q] When did you know?

Well, that moment, sure. But what... because just solving the structure of DNA if nothing else happened afterwards, and seeing how genetic information is stored in a linear fashion, that was a colossal step forward. And you know, the... we could sequence DNA and go on to personal genomes. You know, we'd found the... the structure of the DNA and how it was copied we didn't know how it functioned, and that was, you know... then we had that by '61, in principle, we had transfer in messenger RNA, ribosomes.

I wrote a paper in '64 on the two side model of protein synthesis. Again, it was a simple... that turned out, you know, to be right except there are three sides to a... that didn't really change anything. You know, I just saw it, we were just very lucky that the structure hadn't been solved by Wilkins and Franklin or by Pauling. That is... it was... turned out it was only a three horse race and the first two stumbled. They shouldn't have, neither should have stumbled, but they stumbled. And... and part of the reason they stumbled is that only I really thought that the problem was important, you know? So it was... I wanted to win more than they did because I... I somehow thought it was a bigger prize. Rosalind had virtually never heard of DNA until Randall had told her that she should work on it. Maurice was trained in physics and was always more interested in preventing nuclear war and working for peace than on DNA and feeling there was a bigger problem. And it is.

So, yeah, Francis intellectually knew it was important, but mostly wasn't driven to it until he saw the answer. Because, you know, he saw getting the three-dimensional structure of protein as sufficient intellectual achievement, the main part of that is staying with that was fine. So I was the only person in the world who valued the problem correctly. And you could say, well, why did I? I think it was just... flowed from, you know, the sort of reasoning from facts, you know, and Robert Hutchin's exams. It started with his saying, what is the logical, most likely conclusion? If you start with it you arrive at DNA. The others you can always argue your way out of it, but it's always harder to argue out of it than to say it's yes.