On Daniel Dennett's Darwin's Dangerous Idea.
Darwin's Dangerous Idea changed my life - or perhaps it was the illness that gave me time to read it. I got flu, the flu changed to chronic fatigue, and for many weeks I was incapable of work. But I could read and think.
From my vast pile of "books to be read" I took down Darwin's Dangerous Idea. One reason was my admiration for Dennett's Consciousness Explained. Some reject it as "Consciousness Explained Away" but I agree with Dennett that we are confused about consciousness because the brain spins a false story about a mythical self inside the brain who experiences the world and makes the decisions. I use it in my teaching, even though it is 468 pages long and every page dense with argument. DDI is even longer but then, for a change, I had plenty of time.
Darwin's great insight was that you need only three things: heredity, variation and selection - and then evolution is inevitable. If you have creatures whose offspring resemble them, variation among those offspring and an environment in which only some can survive, then inevitably whatever helps survival will be passed on to the next generation, and the creatures will gradually become better adapted to their environment. For me, Darwin's theory is the most beautiful in all of science.
For Dennett, evolution is an algorithm. This is Darwin's Dangerous Idea - that the algorithmic level is the level that best accounts for the speed of the antelope, the wing of the eagle - and so on. It is "a scheme for creating design out of chaos without the aid of mind". It is a "universal acid" that rips through other explanations and destroys them. It is a recipe for exploring the vastness of design space. And this is how we humans came to be. No God is needed, no grand designer, just a mindless algorithm.
Now algorithms can run on different substrates. What if there were other realms susceptible to Darwin's dangerous idea?
Back in 1976 Richard Dawkins's best-selling book The Selfish Gene came out. I remember enjoying its explanation of genes as selfish "replicators" competing to get into the next generation. But did I notice the last chapter? Perhaps I wrote it off as one of those speculative flings at the end of a great book. In any case I had forgotten all about it until Dennett reminded me. Dawkins had asked the provocative question - are there any other replicators on the planet? - and answered "Yes". Ideas, fashions, behaviours and skills are passed on by imitation and compete to replicate themselves from one brain to another. He called them "memes". A science of memetics has not yet become established, but Dennett took the idea seriously and applied Darwin's algorithm to the design of minds. A person, says Dennett, is a certain sort of ape infested with memes. So that is who I am.
As I lay in bed I began to see the world in a different way. From a "meme's eye view" we are just machines for ensuring their own selfish propagation. Mysteries of human behaviour suddenly began to make sense.
As I get better I am determined not to return to the hectic madness of my previous life or the frustrations of studying paranormal phenomena that almost certainly do not exist. I learnt that what I like doing best is reading and thinking - and writing, of course. Now I am writing my own book on the science of memetics, inspired by the three Ds: Dennett, Dawkins and Darwin.
Susan Blackmore is senior lecturer in psychology, University of the West of England.