The interest in cell adhesion molecules was at its peak in about 1974. I'd spoken about the sciences of recognition which are to my mind evolution itself – development, immunology, and finally the brain... and finally neuroscience. And by that I mean in every case there is a kind of confrontation with an unknown which is solved in one way or another, depending on the mechanics of the system. And I told you that I was deeply influenced by this idea of population thinking, which I think pervades all of these efforts in one way or another, although not everybody would agree with me about that, particularly about the brain. So, as time went on, it became more and more obvious to me that I was going to have to bite the bullet and confront, not only the origin of anatomy which is morphogenesis, but the origin of function and dynamics and all of the things that go along with having a brain. I'd always been interested in this but obviously was filled with trepidation at the thought of having to go near it.

I will date the beginnings of my theoretical interest to an airport crisis which happened in Zurich. In those days we didn't travel as much as we do these days, but a fair amount of my time was spent going back and forth to various places and particularly to Europe, and it was in the Zurich airport that I missed a plane. Now, you have to understand that the texture of travel was quite different then. There was not the same degree of terrorism and fear of it and so you could sort of say, 'Well, you know, I'll wait for another plane.' Well, in this case I couldn't because I'd had the last plane of the day, and I was quite irritated with myself for not showing up on time, but I did have what I think is an original thought. It was: stop being so compulsive, don't worry about going to a hotel; just hang around the airport the way the kids do; sit in a corner and write down your thoughts about the brain. And that's exactly what I did. I stayed there for something like six hours of that effort, and another two hours before I could get another plane. And, in that time, I wrote down what were the skeletal aspects of a theory, a global brain theory. How does the higher order brain work? How does a vertebrate function? And I have to say that this was prompted by two things: the first is my work in embryogenesis which was very focused on the nervous system and on how you made neuroanatomy, and I'll come to that in a moment. The other was the fact that I was a very early member of the Neurosciences Research program.