The Science of Discworld II

and you are listening to. It is being written …
    Philosophically, there ought to be a big difference between a story that is already written, and one that is being created word by word as you read it. The one is a story whose every sentence is predetermined; not only can there be only one possible outcome, but the outcome is already ‘known’. The other is a story whose next sentence does not yet exist, whose ending in unknown even to the storyteller. You are reading the first kind of story, but while we were writing it, it was the second kind of story. In fact, it started out as a totally different story, but we never wrote that one at all. The philosophers realised long ago that it is no easy matter to determine which kind of story fits our world. If we had the ability to run the world again, we might discover that it does different things on the second occasion, and if so, the history of the universe would be a story that unfolds as it goes, not one already committed to paper.
    But this doesn’t look like a feasible experiment.
    Our fascination with stories lays us open to a variety of errors in our relationship with the outside world. The rapid spread of rumours, for instance, is a tribute to how our love of a juicy story overcomes our critical faculties. The mechanism is precisely the one that the scientific method tries very hard to protect us against: believing something because you want it to be true. Or, for some rumours, because you fear it could be true. A rumour is one example of a more general concept, introduced in 1976 by Dawkins in The Selfish Gene . He came up with this notion in order to be able to discuss an evolutionary system that was different from the Darwinian evolution of organisms. It is the meme . The associated subject of ‘memetics’ is science’s attempt to comprehend the power of story.
    The word ‘meme’ was coined by deliberate analogy with ‘gene’, and ‘memetics’ with ‘genetics’. Genes are passed from one generation of organisms to the next; memes are passed from one human mind to another human mind. A meme is an idea that is so attractive to human minds that they want to pass it on to others. The song ‘Happy Birthday to You’ is a highly successful meme; so, for a long time, was Communism, though that was a complicated system of ideas, a memeplex . Ideas exist as some cryptic pattern of activity in brains, so brains,and their associated minds, provide an environment in which memes can exist and propagate. Indeed, replicate, for when you teach a child to sing ‘Happy Birthday to You’, you don’t forget the song yourself. The Hedgehog Song is an equally successful Discworld meme.
    As the home computer spread across the globe, and became inextricably wired into the Internet’s extelligence, an environment was created that gave birth to an insidious silicon-based form of meme: the computer virus. All viruses so far seem to have been written deliberately by humans, although at least one turned out to be a far more successful replicator than its designer had intended, thanks to a programming error. ‘Artificial life’ simulations using evolving computer programs are often run inside a ‘shell’ that isolates them from the outside world, because of the unlikely but possible evolution of a really nasty computer virus. The world’s computer network is certainly complex enough to evolve its own viruses, given enough time.
    Memes are mind-viruses.
    In The Meme Machine , Susan Blackmore says that ‘Memes spread themselves around indiscriminately without regard to whether they are useful, neutral, or positively harmful to us.’ The song ‘Happy Birthday to You’ is mostly harmless, although it is just about possible to see it as an insidious piece of propaganda for global commerce if you’re that way inclined. Advertising is a conscious attempt to unleash memes; a successful advertising campaign starts to build its own momentum as it spreads by word of mouth as well as overt TV or newspaper ads. Some advertising is beneficial (Oxfam, say) and some is manifestly harmful (tobacco). In fact, many memes are harmful, but still propagate very effectively: among them are the chain-letter and its financial analogue, pyramid selling. Just as DNA propagates without having any conscious intentions of its own, so memes replicate without having conscious objectives. The people