I thought that there were two steps in this process. And the two steps I defined in a paper, which I wrote at the time, much later, but they had been defined earlier, and that is you ask the question: how do you build nervous systems? That's one question, and that's what the genes do. And then you ask: how do these nervous systems work to generate behaviour? And the important idea there is exactly the one that we had in molecular biology. You can't understand how this… how the gene corresponds to the phenotype without understanding the paradigm of construction between them, the construction paradigm. Once you understand that phage is put together by molecules into sub-assemblies and these sub-assemblies are glued together to make a phage, you can then understand how the gene, the genetic, the genes correspond to this geometrical structure. And so the same must be true of these higher organisms. And that you then separate the construction issue, the developmental issue, the building issue, from that of function, and the two are then interlocked, because clearly what organisms do is an output from the machines they have to do things with. What machines they have to do things is an output of their genes. So I think that made a clarification and showed that from a genetic point of view the most important question, at least for me, was: how do genes build nervous systems? And that is why I have… I just could not understand how all these people that have this endless argument in the field of behavioural genetics, which was very popular in the early '60s. And there were arguments about genes and intelligence, for example, which aroused tremendous anger of people saying it's just impossible that genes specify intelligence. And what you'd have to do, according to my view, is you'd have to show what is the machine inside the organism that generates intelligence and how do genes affect it? And until you have satisfied that… so that means you have to understand how people display intelligence, and that's one issue, and then you can go to the genes, and of course genes will affect it in the sense that they… they are needed to build your brain – you can't get rid of them, because if you don't have any genes you don't exist, so in that sense you have to do this. And that just means it's not a question of philosophy or belief or any… it's just a question of what it is. And of course you can see that the whole constraint of this is everything has had to be produced by evolution. Intelligence has had to be produced by evolution. Presumably unintelligent people in the early days didn't survive; they couldn't cope with the environment so they were eliminated. And once everything comes to us through this sieve, through this filter, and that filter has to work with genes, then you can see how all of these things are interrelated. And the one thing we can do in a laboratory is to dissect these… separate all these issues and define them in this way. The nematode seemed to be the best way of doing this, and I therefore started what is now known as the C. elegans Project.