Terry Pratchett - The Science of Discworld II - The Globe

They went on staring.

'I mean, elves are just another problem, aren't they?' said Rincewind. Maybe ... maybe they're just another form of big rock? Maybe ... maybe they always turn up when intelligence gets going? And the species is either clever enough to survive them or it ends up buried in the bedrock like all the others? I mean, perhaps it's a kind of, of a test? I mean…

It dawned on Rincewind that he was not carrying the meeting, wizards were glaring at him.

'Are you suggesting that someone somewhere is awarding marks, Rincewind?' said Ponder.

'Well, obviously there is no—'

'Good. Shut up,' said Ridcully. 'Now, lads, let's get back to Mort Lake and get started.'

'Mort Lake?' said Rincewind. 'But that's in Ankh-Morpork!' 'There's one here, too,' said the Lecturer in Recent Runes, beaming.

'Amazing, isn't it? We never guessed. This world is a cheap parody of our own. As Above, So Below and all that.'

'But without magic,' said Ridcully. 'And with no narrativium. It doesn't know where it's going.'

'But we do, sir,' said Ponder, who had been scribbling in notebook.

'Do we?'

'Yes, sir. Remember? In about a thousand years' time it's going to be hit by a really big rock. I keep looking at the numbers, sir, an that's what it means.'

'But I thought we found there'd been a race that built huge structures to get off the place?' 'That's right, sir.'

'Can a new species turn up in a thousand years?'

'I don't think so, sir.'

'You mean these are the ones that leave?'

'It seems like it, sir,' said Ponder.

The wizards looked at the people in the courtyard. Of course, the presence of beer always greases the rungs of the evolutionary ladder, but even so ...

At a nearby table, one man threw up on another one. There was general applause.

T think,' said Ridcully, summing up the general mood, 'that we are going to be here for some time.'

John Dee, who lived from 1527 to 1608, was a court astrologer to Mary Tudor. At one point he was imprisoned for being a magician, but in 1555 they let him out again, presumably for not being one. Then he became an astrologer for Queen Elizabeth I. He devoted much of his life to the occult, both alchemy and astrology. On the other hand, he was also the author of the first English translation of Euclid's Elements, the renowned treatise on geometry. Actually, if you believe the printed word, the book is attributed to Sir Henry Billingsley, but it was common knowledge that Dee did all the work, and he even wrote a long and erudite preface. Which may be why it was common knowledge that Dee did all the work.

To the modern mind, Dee's interests seem contradictory: a mass of superstitious pseudoscience mixed up with some good, solid science and mathematics. But Dee didn't have a modern mind, and he saw no particular contradiction in the combination. In his day, many mathematicians made their living by casting horoscopes. They could do the sums that foretold in which of the twelve 'houses' -the regions of the sky determined by the constellations corresponding to the signs of the Zodiac - a planet would be.

Dee stands at the threshold of modern ways of thinking about causality in the world. We call his time The Renaissance, and the reference is to the rebirth of the philosophy and politics of ancient Athens. But perhaps this view of his times is mistaken, both because Greek society was not then as 'scientific' or 'intellectual' as we've been led to believe, and because there were other cultural currents that attributed to the culture of his times. Our ideas of narrativium may derive from the melding of these ideas into later philosophies, such as of Baruch Spinoza.

Stories encouraged the growth of occultism and mysticism. But they also helped to ease the European world out of medieval superstition into a more rational view of the universe.

Belief in the occult -magic, astrology, divination, witchcraft, alchemy -is common to most human societies. The European tradition occultism, to which Dee belonged, is based on an ancient, secret philosophy; it derives from two main sources, ancient Greek alchemy magic, and Jewish mysticism. Among the Greek sources is the Emeri Tablet, a collection of writings associated with Hermes Trismegist ('thrice master'), which was particularly revered by later alchemists; the Jewish source is the Kabbala, a secret, mystical interpretation of a sacred book, the Torah.

Astrology, of course, is a form of divination based on the stars and the visible planets. It may, perhaps, have contributed to the development of science by supporting people who wanted to observe and understand the heavens. Johannes Kepler, who discovered that planetary orbits are ellipses, made his living as an astrologer. Astrology survives in watered-down form in the horoscope columns of tabloid newspapers. Ronald Reagan consulted an astrologer during his time as American President. That stuff certainly hangs around.

Alchemy is more interesting. It is often said to be an early forerunner of chemistry, although the principles underlying chemistry largely derive from other sources. The alchemists played around with apparatus that led to useful chemists' gadgets like retorts and flasks and they discovered that interesting things happen when you heat certain substances or combine them together. The alchemists' big discoveries were salt ammoniac (ammonium chloride), which can be made to react with metals, and the mineral acids - nitric, sulphuric and hydrochloric.

The big goal of alchemy would have been much bigger if they ever achieved it: the Elixir of Life, the source of immortality. The Chinese alchemists described this long-sought substance as

'liquid gold'. The narrative thread here is clear: gold is the noble metal, incorruptible, ageless. So anyone who could somehow incorporate gold into his body would also become incorruptible and ageless. The nobility shows up differently: the noble metal is reserved for the 'noble' humans: emperors, royalty, the people on top of the heap. Much good did this do them. According to the Chinese scholar Joseph Needham, several Chinese emperors probably died of elixir poisoning.

Since arsenic and mercury were common constituents of supposed elixirs, this is hardly a surprise. And it is all too plausible that a mystic quest for immortality would shorten life, not prolong it.

In Europe, from about 1300 onwards, alchemy had three main objectives. The Elixir of Life was still one, and a second was finding cures for various diseases. The alchemical search for medicines eventually led somewhere useful. The key figure here is Phillipus Aureolus Theophrastus Bombastus [19] Isn't 'Bombastus' a lovely name? Well-chosen, too. von Hohenheim, mercifully known as 'Paracelsus', who lived from

1493 to 1541.

Paracelsus was a Swiss physician whose interest in alchemy led him to invent chemotherapy. He placed great store in the occult. As a student aged 14 he wandered from one European university to another, in search of great teachers, but we can deduce from what he wrote about the experience, somewhat later, that he was disappointed. He wondered why 'the high colleges managed to produce so many high asses', and clearly wasn't the kind of student to endear himself to his teachers. 'The universities,' he wrote, 'do not teach all things. So a doctor must seek out old wives, gypsies, sorcerers, wandering tribes, old robbers, and such outlaws and take lessons from them.' He would have had a high old time on Discworld, but would have learned a lot.

After ten years' wandering, he returned home in 1524 and became lecturer in medicine at the university of Basel. In 1527 he publicly burned the classic books of earlier physicians, the Arab Avicenna and the Greek Galen. Paracelsus cared not a whit for authority. Indeed his assumed name, 'para-Celsus', means 'above Celsus', and Celsus was a leading Roman doctor of the first century.