I think that classifying the world, which we do as babies, we start doing it as babies. I mean what you can eat and what tastes rotten or hurts you or damages you, you know, goes right to the very beginning, doesn’t it, of experience, and then explaining, how is explaining linked to classifying? I mean a baby obviously won’t ask why is this particular food sweet and that sour or this upsets my tummy and that one’s all right, but as you go through adult life you gradually learn why certain things are good or bad, why they work the way they do. You classify them in many, many ways and the classification is generally related in some degree with explanation. For example, you’d say that something is part of physics, something is part of psychology or it’s God affecting things, or it’s spooky or something, you know, I mean you get the sort of primitive and then subtle kinds of explanation, classification, of phenomena, and I think one of the really interesting things is how- the way you classify the world of events and objects relates to the kinds of explanations that you adopt. How do you get the appropriate explanation to the phenomena? And I think this is very, very difficult in psychology, to relate the kind of explanation to the kind of problem the person has or the process going on in the brain or the mind. I think this is a really tricky business. Now, I’ve taken illusions because these are clear cut phenomena, some of them are due to the physiology going wrong, others to the strategies, cognitive strategies, cognition of the brain, the mind being inappropriate, and this is very, very different if it’s working inappropriately to the problem, or if the mechanism’s not working correctly, these are quite different, like a hardware fault or a software fault in a computer, it’s an initial classification. So what I’ve been trying to do is to develop a sort of detailed classification, a visual phenomena. Now, that’s relatively easy because the phenomena clear cut, for example, there are illusions where you get lines which get bent like that, distortion illusion, or something that looks too big or it looks too small. You get other illusions where you see something that simply isn’t there, you can make ghosts, visual ghosts very, very easily. You can have other illusions which flit from one thing to another, they’re ambiguous like a wire cube or flip inside out or duck and a rabbit will interchange and the same shape or even the same object will suddenly become a duck, suddenly a rabbit. Now, the question is, since one can classify these phenomena fairly easily, for example, you’ve got distortions, you’ve got ambiguities, you’ve also got paradoxes, some objects look absolutely impossible, which is interesting. Why can’t one use the clear cut cases of perception to find out how to classify mental phenomena on the grounds that these are easy, simple, easy to study, we can all see them, we can pretty well agree on the classes. Then you think of the explanations and it then becomes a scientific question, whether the explanations are adequate or not or appropriate, you do experiments for that but I think to get that straight, then to move into difficulties of the mind, abnormal problems, mental disease, if you like, continue the classification, develop it, develop the discipline of studying each one and testing whether it’s the right way of thinking about it or not, could be a way to do psychology, starting really with perception because it has rich phenomena which is clear cut which we can all agree about and one can quite easily do experiments on them. One can relate them to brain physiology with FMRI, brain imaging and so on, and then from there move in to the really difficult stuff that people like Freud were talking about, which is much, much harder for real science to penetrate. My feeling is this might be the way to do it, by classifying, explaining each class of phenomenon in its own way, relating the classification to the kind of explanation as in astronomy with stars, if you like, and then move into the mind that way. I think this is perhaps how the science of psychology might work, might continue into the future. So what I’m trying to do in my humble way is to develop this classification of phenomena of illusions and explain them, that’s what I’m trying to do.