One of the hoariest of science fictional archetypes is the idea of the artificial intelligence — be it the tin man robot servant, or the murderous artificial brain in a box that is HAL 9000. And it’s not hard to see the attraction of AI to the jobbing SF writer. It’s a wonderful tool for exploring ideas about the nature of identity. It’s a great adversary or threat (‘War Games’, ‘The Forbin Project’), it’s a cheap stand-in for alien intelligences — it is the Other of the mind.

The only trouble is, it doesn’t make sense.

Not only is SF as a field full of assumed impossibilities (time machines, faster than light space travel, extraterrestrial intelligences): it’s also crammed with clichés that are superficially plausible but which don’t hang together when you look at them too closely. Take flying cars, for example: yes, we’d all love to have one — right up until we pause to consider what happens when the neighbour’s 16 year old son goes joy riding to impress his girlfriend. Not only is flying fuel-intensive, it’s difficult, and the failure mode is extremely unforgiving. Which is why we don’t have flying cars. (We have flying buses instead, but that’s another matter.) Food pills out-lived their welcome: I think they were an idea that only made sense in the gastronomic wasteland of post-war austerity English cuisine. I submit that AI is a similar pipe dream.

This is not to say that we’re never going to know what the basis of consciousness is, or that it’s going to turn out to be non-computable. If anything, the prospects for scientists working to discover just how our own brains work to generate this strange phenomenon are very promising. While the initial direction of research in artificial intelligence (from the 1960s to the 1980s) turned out to be frustratingly inapplicable — consciousness does not, it appears, run on easily encoded symbolic logic — we’ve developed a lot of useful techniques along the way. Indeed, computer scientists joke that if we know how to do something it isn’t artificial intelligence any more. The world’s best chess player is a computer program; likewise the champion of the TV quiz show Jeopardy. Meanwhile, neurobiologists are mapping and decoding the deep structure of our brains using a variety of non-invasive imaging techniques, and our understanding of how brains are put together at the neural level is deepening rapidly.

But knowing how to build a flying car is not the same thing as making a business case for mass producing them. And knowing how human minds work isn’t the same as making a case for deploying synthetic minds in software.

For one thing, there are huge ethical problems associated with attempting to simulate a human brain, or building a piece of software that could become self-aware. If you terminate a conscious program, are you committing murder? Quite possibly. Worse: if you use genetic algorithms to evolve a conscious AI, iteratively spawning hopeful mutants and then reaping them to converge on a final goal, are you committing genocide? (Australian SF author Greg Egan reluctantly came to this conclusion a couple of years ago: I can’t fault his logic.) And if you create an AI solely for the purpose of doing some kind of cognitive function, does this amount to slavery?

These questions ought to give advanced researchers pause for concern — and a swift referral to the nearest academic ethics committee. But leaving aside ethics — positing for the time being that any use we make of a software intelligence is no more morally questionable than using a spreadsheet — there are further problems. Consciousness appears to be an emergent property of a bunch of converging non-conscious processes within the brain. And it’s not a primary actor — rather, it’s a monitoring and coordinating function. It comes with a whole bunch of undesirable characteristics. Conscious minds experience boredom and emotional upsets (and it appears emotions play a fairly significant role in generating consciousness). They are self-motivated and go off on wild goose chases. If we ever could produce a true artificial intelligence in a box, we’d probably find it utterly useless for any productive purpose — more inclined to watch Reality TV all day, troll the internet, or invent crankish new religions than to open the pod bay doors on demand.