Terry Pratchett - The Science of Discworld III - Darwin's Watch

What, then, is causality? For Damasio-like reasons, we tend to think that what gives history its dynamic is the big events, the `pivot points'. The fallacy is that we think big causes are needed to produce big effects. This is false (butterfly) but there is a problem: choosing the right tiny change (which butterfly?). And there are always billions of new butterflies, dragging new changes out from previously invisible differences `in the 13th decimal place', unobservable until their effects show up.

Real history is like this; causes are often distributed, with huge numbers of tiny events all coming together. It is just this problem that leads Ridcully to employ such a huge number of wizards, doing such a bizarre set of trivial things, merely to get The Origin written.

We only justify this sort of causality in retrospect: history didn't know `where it was going'. So changing the past creates a context for the future, not a causal chain, and this is how the wizards must operate, which is why we have thousands of them making endless trivial changes to Victorian history, instead of, say, assassinating Queen Victoria. Any Victorian, perhaps particularly the well-trained nursemaid, will tell you just that about your personal history: your heart must be pure (context) rather than your plans being subtle.

CHARLES DARWIN WAS SITTING ON a grassy bank. Three types of bee buzzed among the flowers, and overhead examples of Hirundo rustica swooped after miscellaneous Ephemeroptera.

His thoughts were complex, as human thoughts tend to be when the mind is idling, but included: this is an interesting bank of astonishing complexity; there might be fish for lunch; he had a sore throat; he hoped never to receive another letter about barnacles; the rash seemed to be getting worse; there was a strange buzzing sound; had he really experienced that apparition?; homeopathy transcended all common sense; he really should find out where the ovaria were situated in Phyllosoma; it really was a very loud buzzing ...

Something like a yellow-brown smoke was issuing from a hole in the bank a few yards away, and resolved itself into a cloud of angry Vespula vulgaris. It bore down on the horrified Darwin -

'Over here, waspies!'

Darwin stared.

This mission had created a difficult decision for Rincewind, when he'd been presented with the task of preventing Charles Darwin being stung to death by wasps. Right from the start it was obvious that Darwin would see, him, and if Rincewind was invisible the wasps wouldn't see him. He'd therefore undertaken the mission carrying two buckets of warm jam and wearing a pink tutu, an acid-green wig and a red nose, reasoning that (a) Darwin wouldn't believe that he had seen him and in any case (b) wouldn't dare tell anyone ...

Darwin watched the apparition skip away over the fields. It was quite astonishing. He'd never seen wasps swarm in such a manner.

A piece of paper fluttered to the ground. The curious clown must have dropped it.

Darwin picked it up and read, aloud, "`Return me, Hex". What does-?'

The afternoon dozed on. The grassy bank went back to its buzzing, humming, flowering busyness.

On the forlorn shore, a man appeared, hid two buckets behind a rock, and removed his false nose.

Rincewind scanned the landscape while extracting his hat from inside his shirt.

This was one of the most famous islands in the history of technomancy? It looked, frankly, rather dull.

He'd been expecting forests and streams and a riot of creatures. You couldn't move for vibrant, striving life on Mono Island, home of the God of Evolution. Everything wanted to leave. But this place had a skinflint look. You'd need to be tough to survive here. You'd have to fit in.

He couldn't see any giant tortoises, but there were a couple of large, empty shells.

Rincewind picked up a length of driftwood, baked by the sun into something like stone, and hurried up a narrow path.

Hex was good. The man Rincewind was after was striding ahead of him along the track.

`Mr Lawson, sir!'

The man turned.

`Yes? Are you from the Beagle?'

`Yessir. Heave ho, sir,' said Rincewind. Lawson stared at him. `Why do you wear that hat with "Wizzard" written on it?' Rincewind thought fast. Thank goodness Roundworld had some strange customs.

`Crossing the Line ceremony, sir,' he said. `Took a fancy to it!' `Oh, King Neptune and so forth,' said Lawson, backing away a little. Jolly good. How can I help you?'

'Just wanted to shake you by the hand and say how glad we all are that you're doing such a wonderful job out here, sir,' said Rincewind, pumping the man's unresisting arm vigorously. `We ... that's is very kind of you, Mr - what was that noise?' `Sorry? Shiver my timber, by the way.'

`That ... whistling noise ... ' said Lawson, uncertainly.

`Probably one of the tortoises?' said Rincewind, helpfully.

`They hiss or - wasn't that a thump?' said Lawson. Behind him, a small cloud of dust rose above the bushes.

`Didn't hear one, yo ho,' said Rincewind, still shaking the hand. `Well, don't let me keep you, sir.'

Lawson gave him the look of a man who feels has inadvertently fallen into dribbling company. The hat was clearly preying on his mind.

`Thank you, my man,' he said, pulling his hand away. `Indeed, I must go.'

He headed away at some speed, which increased when he noticed Rincewind following him, and completely failed to notice what was, after all, just another small, rubble-filled hole among many. Rincewind spotted it, though, and after some effort pulled out a small, warm lump.

Something hissed, behind him.

Rincewind had ascertained that the only way a giant tortoise could go as fast as him was by falling over a cliff, and also that they were highly unlikely to savage a man to death. Still, he was ready.

He turned, stick upraised.

Something, a greyish something, something just transparent enough to show the landscape behind it in a dreary light, was hovering a few feet away. It looked like a monk's robe for a very small monk, and minus the monk. The empty hood was more worrying than almost anything that could have filled it. There were no eyes, there was no face, but there was nevertheless a stare, as malignant as razorblade pants.

Other robe-shadows appeared around the shape and began drifting towards it. When they reached it they vanished, and the central shape became darker and, somehow, more present.

Rincewind didn't turn and run. There was no point in trying to run from Auditors; they were certainly faster than anything with legs. But that wasn't the reason. If it was time to run, he'd considered, no other calculations applied. He wouldn't even worry that his escape route was blocked by solid lava; most things could be overcome if you ran at them hard enough. There was, however, another reason. It had pink toes.

`Why meddle?' said the Auditor. The voice sounded windy and uncertain, as if the speaker was having to assemble the words by hand. `Entropy will always triumph.'

`Is it true that you die if you have an emotion?' said Rincewind. The Auditor was quite dark now, which meant that it has assembled enough mass to move something quite heavy, like a human head.

`We do not have emotion,' said the Auditor. `It is a human aberration. In you we detect the physical manifestation recognisable to us as fear.'

`You can't just kill people, you know,' said Rincewind. `That's against the rules.'

`We believe there may be no rules here,' said the Auditor, moving forward.

`Wait, wait, wait!' said Rincewind, trying to back away into solid rock. `You're saying you don't know what fear is, right?'

`We have no requirement to do so,' said the Auditor. `Prepare to cease coherent function.'

`Turn around,' said Rincewind.