1. What are your latest ideas about the mind, as set out in The Emotion Machine?

The theme of the book is that humans are uniquely resourceful because they have several ways to do everything. If you think about something, you might think about it in terms of language, or in logical terms, or in terms of diagrams, pictures, or structures. If one method doesn’t work, you can quickly switch to another. That’s why we’re so good at dealing with so many situations. Animals can’t imagine what the room would look like if you change that couch from black to red. But a person has ways of constructing mental images or sentences or bits of logic.

Neuroscientists’ quest to understand consciousness is a hot topic right now, yet you often pose things via psychology, which seems to be taken less seriously. Are you behind the curve?

I don’t see neuroscience as serious. What they have are nutty little theories, and they do elaborate experiments to confirm them and don’t know what to do if they don’t work. This book presents a very elaborate theory of consciousness. Consciousness is a word that confuses possibly 16 different processes. Most neurologists think everything is either conscious or not. But even Freud had several grades of consciousness. When you talk to neuroscientists, they seem so unsophisticated; they major in biology and know about potassium and calcium channels, but they don’t have sophisticated psychological ideas. Neuroscientists should be asking: What phenomenon should I try to explain? Can I make a theory of it? Then, can I design an experiment to see if one of those theories is better than the others? If you don’t have two theories, then you can’t do an experiment. And they usually don’t even have one.

So as you see it, artificial intelligence is the lens through which to look at the mind and unlock the secrets of how it works?

Yes, through the lens of building a simulation. If a theory is very simple, you can use mathematics to predict what it’ll do. If it’s very complicated, you have to do a simulation. It seems to me that for anything as complicated as the mind or brain, the only way to test a theory is to simulate it and see what it does. One problem is that often researchers won’t tell us what a simulation didn’t do. Right now the most popular approach in artificial intelligence is making probabilistic models. The researchers say, “Oh, we got our machine to recognize handwritten characters with a reliability of 79 percent.” They don’t tell us what didn’t work.

Neuroscientists like Oliver Sacks and V. S. Ramachandran study people who have brain injuries; to them, what is not happening in the brain is more informative than what is happening. Is that similar to what you’re saying?

Yes. In fact, those are just about the two best thinkers in that field. Antonio Damasio is pretty good, but Ramachandran and Sacks are more sophisticated than most. They consider alternative theories instead of trying to prove one particular theory.

2. Is there other work in neuroscience or ai that interests you?

Very little. There are 20,000 or 30,000 people working on neuronetworks, and there are 40,000 or 50,000 people working on statistical predictors. There are several thousand people trying to get logical systems to do commonsense thinking, but as far as I know, almost none of them can do much reasoning by analogy. This is important because the way people solve problems is first by having an enormous amount of commonsense knowledge, like maybe 50 million little anecdotes or entries, and then having some unknown system for finding among those 50 million old stories the 5 or 10 that seem most relevant to the situation. This is reasoning by analogy. I know of only three or four people looking at this, but they’re not well-known because they don’t make grandiose claims of looking for a theory of everything.