The Science of Discworld II

to move us back again.’
    The Librarian watched them go.
    A moment later, the rest of everywhere went with them.

FOURTEEN
POOH AND THE PROPHETS
    T HE U GS HAVE NO REAL STORIES , hence no sense of their place in time. They have no conception of the future, and therefore no wish to change it.
    We know that there are other futures …
    As Ponder Stibbons remarks, we live in a multiplex universe. We look at the past and we see times and places where things could have been different, and we wonder whether we could have ended up in a different present. By analogy, we look at the present and imagine many different futures. And we wonder which of them will happen, and what we can do now to affect the choice.
    We could be wrong. Maybe the fatalist view, ‘it is written’, is right. Maybe we are all automata, working out the deterministic future of a clockwork universe. Or maybe the Quantum philosophers are right, and all possible futures (and pasts) coexist. Or maybe everything that exists is just one point in a multiplex phase space of universes, a single card dealt from Fate’s deck.
    How did we acquire this sense of ourselves as beings who exist in time? Who remember their past, and use it to try (usually unsuccessfully) to control their future?
    It all goes back a long, long way.
    Watch a proto-human watching a zebra watching a lioness. The three mammalian brains are doing very different things. The herbivore brain has seen the lioness, is barely conscious (we guess, watch some horses in a field) of the whole 360 degrees of his environment, and hasmarked some things, like that tuft of grass over there, that female over there who could just be in heat, that male who’s giving her the right signals, the three bushes that could have a surprise behind them … If the lioness moves, she suddenly gets priority, but not totally because there are other considerations. Another lioness could well be behind those bushes, and I’d better move up on that nice grass before Nigella does … Looking at that grass makes me think of the taste of that long grass … THE LIONESS IS MOVING.
    The lioness is thinking: that’s a nice zebra stallion, won’t go for him, he’s too strong (memory of a previous eye injury from a zebra kick), but if I get him running, Dora behind those bushes can probably jump on the young female over there who is trying to attract the male, then I can run after it with her …
    There is probably no more of a plan than that in the zebra’s brain, but it does foresee a little bit of the future and plug memories into present planning. If I stand up now …
    The human is looking at the lioness and the zebra. Even if it’s a Homo erectus , we bet it had stories in its head: that lioness will run out, the zebra will startle, the other lioness will go for … ah, that young female. Then I can run out there and get in front of the young male; I see myself running at him and hitting him with this stone. Homo sapiens may well have done better from the beginning; his brain was bigger and probably better. He may, from the beginning, have had room for several alternative, thought-about ‘or’ scenarios and probably the ‘and’ one which goes ‘and I will be a big hunter and meet interesting women’. ‘If’ probably came along later, perhaps with cave paintings, but making predictions put our ancestors way ahead of their predators and their prey.
    There has been a variety of suggestions about why our brains suddenly grew to nearly double their previous size, from the need to keep the faces of our social group in mind while gossiping about them, to the need to compete with other hunter-gatherers, to the competitive nature of language and its structuring of the brain so that lying could be successful for the li-ar, but then the li-ee got better at detecting lies. Such escalations all have an attraction to them. They make good stories, ones that we can easily imagine, filling in the background just aswe do with hearing sentences or enjoying pictures. That doesn’t make them true, of course, just as our attraction to the supposed seashore phase of our history doesn’t make ‘aquatic apes’ true either. The stories serve as placeholders for whatever the real pressures were: the meta-explanation of why our brain growth took off is that competitive advantage was to be won by All Of The Above routes, and many more.
    Perhaps