Well, there's one thing I've left out and it's a very important thing philosophically speaking or morally speaking... I don't know how to put it. And that is the so-called idea of value. All of this occurs somatically in an individual according to this theory but it can't occur unless you've already inherited something that we call value. Let me illustrate that by a concept... how do I put it? By... by saying there are, there are anatomical structures in the brain, about six of them, called value systems. For instance if I go like this, your locus coeruleus which is a set of little blue spots about 6000 neurons each, release noradrenalin all over your brain through a leaky hose. If I have you tested and you're trying to perform something for a reward, you release dopamine through another set of signals coming from parts of the ventral tegmentum and also something called the basal ganglia. If I go to other parts of the brain, it's acetylcholine. There are these diffuse ascending systems that you are born with that have been selected by evolution to give you rewards or punishments if you will, according to your behavior. Those condition the selection I mentioned in this ternary relationship, developmental, experiential and re-entry. So you have this system working together and that was the gist of the theory I put together in Zurich.

Well, since then it's been elaborated much more completely and, indeed, in 1987 I published a book called Neural Darwinism. Well, that released a bit of a storm and I found out that, independent of its merits, if you want to have a lot of disturbance around you, theorize in biology. There's no doubt that it's a little bit different than in physics. In any case the book gave a much more extensive analysis of the situation from more points of view and of the developing theory, and it also of course looked for evidence to support the theory. Now, as you know, there's no way you can prove a theory in science; there's only a way you can perhaps disprove it. And so far I'm happy to report the theory hasn't been disproven. I personally believe it is terribly important to have that theory because, unlike the other organs that develop, as complex as they are; say the kidney or the liver, the brain is after all giving rise to these amazing properties of knowledge, consciousness, all of the philosophical notions etc., etc., epistemology, how you know, how it all goes together, language. So how does this all go together in this disparate mess? There are so many different levels of organization in that brain that you're struck through with awe when you really look at the complexity of it.

Well, the position I took on the theory was this: that maybe we can't prove it, because you can't do that with a scientific theory, but at least we can show it's self-consistent. And so, as a result of that, my colleagues and I have run a series of brain models. We've made models of these different processes that I talked about, and shown that at least the theory is self-consistent. If you try to express a theory like this just in words, the complexity is not embedded. You've got to go into details and see how that goes, and in a series of publications we did just that. Again you notice the word ‘we’ because in fact I've been fortunate to be joined by a number of people, particularly at this institute, who are interested in this issue.