So this audience was ripe for persuasive texts that could take them out of simple biblical knowledge into new theologies, even into atheism. Huxley, `Darwin's Bulldog', promoted Darwinism as the antithesis of a God-made world. From the aspiring middle class of Victoriana grew our modern secular age, with God relegated to the plaything of a few of the less modern clergy. Modern clergy don't believe in a twelve-foot Englishman up there in the sky, with Heaven as an eternal Buckingham Palace garden party. Particularly from those French philosophers who continued sophisticated theological criticism in lineages derived from Voltaire, our clerics learned to do without that strong Victorian style of Christianity. That form of Anglicanism, confident that God really was looking after the English, didn't need to embarrass itself with overt prayers. The rituals would suffice (provided they weren't noisy like the Welsh, or showy like the Catholics).

We have lost strong simple religion, we have lost academic excellence, we have gained a secular society that maintains the heterogeneity that made it so robust in Victorian times and later. However, we are now pursuing policies, particularly in education, that fail to provide society with all those able people who built the Victorian and Edwardian edifices, both material and theoretical.

There are routes away from this pessimism. In The Science of Discworld 2 we referred to humans as Pan narrans, the storytelling chimpanzee. Our overall message was that humans need to make stories to motivate themselves, to identify goals, and to distinguish good from evil.

Here we go a step further.

Technological and Civilised Man, we believe, must become Polypan multinarrans,[1] to extend the metaphor rather further. Human beings must become ever more diverse, valuing and enjoying each other's differences rather than fearing them or suppressing them. And mere explanation is not enough. To gain understanding, a useful working philosophy as appropriate for action as for judgement and

[1] Sorry, it's one of those horrible Graeco-Latin hybrids. But, like `television', it's comprehensible.

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. The final 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 planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.

THE ENTANGLED BANK

IT WAS MIDNIGHT IN THE museum's Central Hall when the wizards appeared. There were a few lights on; just enough to see the skeletons.

`Is this a temple of some kind?' said the Chair of Indefinite Studies, patting his pockets for his tobacco pouch and a packet of Wizlas. `One of the weirder ones, perhaps?'

+++ Indeed +++ boomed the voice of Hex from the middle air.

+++ In all the universes of the The Ology, it was the Temple of the Ascent of Man. Here, it is not +++

`Very impressive,' muttered the Dean. `But why don't we just show him the big snowball? He'd be pretty pleased to know it was because of him humans got away.'

`We've scared the poor chap enough, that's why!' snapped Ridcully. `He'll understand this. Hex says they started building when Darwin was alive. Stuffed animals, bones ... it's the kind of thing he knows. Now stand back and give the chap some air, will you?'

They stepped away from the chair on which Charles Darwin had been transported, wreathed in the blue light. Ridcully snapped his fingers.