Lies-to-children, even the broadsheet newspaper sort, are mostly benign and helpful, and even when they are not, they are intended to be that way. They are constructed with the aim of opening a pathway that will eventually lead to more sophisticated lies-to-children, reflecting more of the complexities of reality. We teach science and art and history and economics by a series of carefully constructed lies. Stories, if you wish ... but then, we've already characterised a story as a lie.

The science teacher explains the colours of the rainbow in terms of refraction, but slides over the shape of the rainbow and the way those colours are arranged. Which, when you come to think of it, are more puzzling, and more what we want to know about when we ask why rainbows look like they do. There's a lot more to the physics than a raindrop acting as a prism. Later, we may develop the next level of lie by showing the child the elegant geometry of light rays as they pass through a spherical raindrop, refracting, reflecting, and refracting back out again, with each colour of light focused along a slightly different angle. Later still, we explain that light does not consist of rays at all, but electromagnetic waves. By university, we are telling undergraduates that those waves aren't really waves at all, but tiny quantum wave-packets, photons. Except that the 'wave-packets' in the textbooks don't actually do the job ... And so on. All of our understanding of nature is like this; none of it is Ultimate Reality.

LACK OF WILL

The wizards were never quite certain where they were. It wasn't their history. History gets named afterwards: The Age of Enlightenment, the Depression. Which is not to say that people sometimes aren't depressed with all the enlightenment around them, or strangely elevated during otherwise grey times. Or periods are named after kings, as if the country was defined by whichever stony-faced cut-throat had schemed and knifed his way to the top, and as if people would say, 'Hooray, the reign of the House of Chichester - a time of deep division along religious lines and continuing conflict with Belgium -is now at an end and we can look forward to the time of the House of Luton, a period of expansion and the growth of learning! The ploughing of the big field is going to be a lot more interesting from now on!'

The wizards had settled for calling the time they'd arrived 'D' and, now, they were back there, in some cases quite suntanned.

They had commandeered Dee's library again.

'Stage One seemed to have worked quite well, gentlemen,' said Ponder Stibbons. 'The world is certainly a lot more colourful. We do seem to have, er, assisted the elves in the evolution of what I might venture to call Homo narrans, or "Storytelling Man".'

'There's still religious wars,' said the Dean. 'And still the heads on spikes.'

'Yes, but for more interesting reasons,' said Ponder. 'That's humans for you, sir. Imagination is imagination. It gets used for everything. Wonderful art and really dreadful instruments of torture.

What was that country where the Lecturer in Recent Runes got food poisoning?'

'Italy, I think,' said Rincewind. 'The rest of us had the pasta.'

'Well, it's full of churches and wars and horrors and some of the most amazing art. Better than we've got at home. We can be proud of that, gentlemen.'

'But when we showed them the book the Librarian found in L-space, of Great Works of Art with the full colour pictures ...' mumbled the Chair of Indefinite Studies, as if he had something on his mind but wasn't certain how to phrase it.

'Yes?' said Ridcully.

'... well, it wasn't actually cheating, was it?'

'Of course not,' said Ridcully. 'They must have painted them somewhere. Some other dimension.

Something quantum. A parallel eventuality or something with that sort of a name. But that doesn't matter. It all goes round and round and it comes out here.'

'But I think we said too much to that big chap with the bald head,' said the Dean. 'The artist, remember? Could've been the double of Leonard of Quirm? Beard, good singing voice? You shouldn't have told him about the flying machine that Leonard built.'

'Oh, he was scribbling so much stuff no one'll take any notice,' said Ridcully. Anyway, who'll remember an artist who can't get a simple smile right? The point is, gentlemen, that the fantastic imagination and the, er, practical imagination go hand in hand. One leads to the other. Can't separate them with a big lever. Before you can make something, you have to picture it in your head.'

'But the elves are still here,' said the Lecture in Recent Runes. 'All we've done is do their work even better! I don't see the point!'

Ah, that's Stage Two,' said Ponder. 'Rincewind?'

'What?'

'You're going to talk about Stage Two. Remember? You told us you wanted to get the world to the right stage?'

'I didn't know I had to make a presentation!'

'You mean you don't have any slides? No paperwork at all?'

'Paperwork slows me down,' said Rincewind. 'But it's obvious, isn't it? We say Seeing is Believing ... and I thought about that, and it's not really true. We don't believe in chairs. Chairs are just things that exist.'

'So?' said Ridcully.

'We don't believe in things we can see. We believe in things that we can't see.'

'And?'

'And I've been checking this world against L-space and I think we've made it the one where humans survive,' said Rincewind. 'Because now they can picture gods and monsters. And when you can picture them, you don't need to believe in them any more.'

After a long silence the Chair of Indefinite Studies said, 'Is it just me, or has anyone else noticed how many huge cathedrals they've been building on this continent? Big, big buildings full of wonderful craftsmanship? And those painters we talked to have been very keen on religious paintings ...'

'And your point is ... ?' said Ridcully.

'It's just that this has been happening at the same time as people have been really taking an interest in how the world works. They're asking more questions. How? and Why? and questions like that,' said the Chair of Indefinite Studies. 'They're acting like Phocian but without going mad. Rincewind seems to be suggesting that we're killing off the gods of this place.'

The wizards looked at him.

'Er,' he went on, 'if you think a god is huge and powerful and everywhere, then it's natural to be god-fearing. But if someone comes along and paints that god as a big bearded chap in the sky, it's not going to be long before people say, don't be silly, there can't be a big bearded man on a cloud somewhere, let's go and invent Logic.'

'Can't there be gods here?' said the Lecturer in Recent Runes. 'We've got a mountaintop full of

'em at home.'

'We've never detected deitygen in this universe,' said Ponder thoughtfully.

'But it's said to be generated by intelligent creatures, just like cows generate marsh gas,' said Ridcully.

'In a universe based on magic, certainly,' said Ponder. 'This one is just based on bent space.'

'Well, there's been lots of wars, lots of deaths and I'd bet there's lots of believers,' said the Chair of Indefinite Studies, now looking extremely uncomfortable. 'When thousands die for a god, you get a god. If someone is prepared to die for a god, you get a god.'

'At home, yes. But does that work here?' said Ponder.

The wizards sat in silence for a while.

'Are we going to get into any sort of religious trouble for this?' said the Dean.

'None of us has been struck by lightning yet,' said Ridcully.

'True, true. I just wish there was a less, er, permanent test,' said the Chair of Indefinite Studies.

'Er ... the dominant religion on this continent seems to be a family concern, somewhat similar to Old Omnianism.'