Science of Discworld III

action as for judgementand decision, an explanation is only rarely good enough. People find simple explanations satisfying because they enable thin causal chains of the kind we build for our own personal memories and causalities. But the real world, even the world of other people and their likes, dislikes, and prejudices – sometimes so rigidly held that our own lives and those of our loved ones don’t matter to them – doesn’t work like that.
    We owe it to ourselves, and to those for whom we are responsible and those who respect us, to develop multi-causal understanding. We can do that, as suggested here, by simultaneously encompassing several explanations of each puzzle, explanations that disagree productively with each other. Multinarrans : many stories. So one person, even a Newton or a Shakespeare or a Darwin, will not really be enough, despite the story we have just told you. Our fictional Darwin is a symbol for an endless stream of Darwins, challenging orthodoxy and being right , a glorious network of innovative thinkers and radicals. People who try to keep ancient cultures alive by blowing up the competition achieve nothing, except widespread contempt for their objectives. They doom their own enterprise by their methods, and they betray a terrible lack of confidence that what matters to them can survive without coercion and violence.
    Back to sergeants, and the way things are really done: ‘Sergeant, dig a trench.’ This is how Polypan multinarrans gets things done. How many people are needed to understand a jet airliner? To build one? Recursion in technology really is like biological evolution, it really does expand the phase space. It expands it so much that most of us have virtually no understanding of how the world we live in works. In fact, it is essential that we don’t, because there would be too much for anyone to understand.
    But we do need to understand that this is what the world is like. Otherwise we don’t just lose the sergeants: we lose the ability to build aircraft that fly, dishwashers that clean, cars that don’t pollute (as much). We stop being able to cure (some of) the sick, to feed (most of)the planet, and to house, clothe, and wash a burgeoning humanity.
    Our world is changing, and it’s changing very fast, and we ourselves are the inescapable agents of that change. If we stagnate, like our fictional Victoriana, we die. Staying where we are is not an option. Static resources cannot continue to support us.
    We make our world work by introducing new, undreamt-of rules and possibilities, by considering alternatives and making decisions, which feel like ‘free will’, and work that way, even if they are ‘really’ deterministic. We build on the present to create a bigger future. Science standing on technology, and technology standing on science, provide a successful ladder that leads to extelligence.
    Is it, perhaps, the only one?
    The past was another country, but the future is an alien world.
    And yet …
    The most remarkable thing about the universe, as Einstein once said, is that it is comprehensible. Not in every aspect, but in enough to make us feel at home in it. It makes sense – almost as much as a Discworld story. Which is amazing because facts don’t have to make sense: only well-crafted fiction has to obey such rigid rules.
    Part of this comprehensibility can be explained. We evolved in the universe, and we evolved to survive in it. Being able to tell ourselves ‘what if’ stories about it – to understand it – has survival value. We have been selected, by nature, to tell such stories.
    What is less easy to explain is why the universe can be represented by human stories at all. But then, if it wasn’t, we wouldn’t be telling them, would we?
    Which brings us back to Charles Darwin, architect of our own present, which was his future, and would surely seem alien to any Victorian. In Chapter 18 we left him sitting on an ‘entangled bank’, watching birds and insects, and musing on the nature of life. Thefinal paragraph of The Origin , which began with gentle musings about entangled banks, now works its way to its revolutionary conclusion:
    From the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this