The Science of Discworld (Science of Discworld, #1)

by Terry Pratchett

We could, for example, have pointed out that Darwin’s theory of evolution explains how lower lifeforms can evolve into higher ones, which in turn makes it entirely reasonable that a human should evolve into an orangutan (while remaining a librarian, since there is no higher life form than a librarian).

Dragons don’t breathe fire because they’ve got asbestos lungs – they breathe fire because everyone knows that’s what dragons do.

We have always had a drive to paint stories on to the Universe. When humans first looked at the stars, which are great flaming suns an unimaginable distance away, they saw in amongst them giant bulls, dragons, and local heroes.

To a scientist, a thought experiment is an argument that you can run through in your head, after which you understand what’s going on so well that there’s no need to do a real experiment, which is of course a great saving in time and money and prevents you from getting embarrassingly inconvenient results.

Sometimes, the best answer is a more interesting question.)

PPS Sometimes scientists change their minds. New developments cause a rethink. If this bothers you, consider how much damage is being done to the world by people for whom new developments do not cause a rethink.

Wizards can put up with any amount of deprivation and discomfort, provided it is not happening to them.

You could walk to the Moon in about thirty years – given a path, air, and the usual appurtenances of the experienced traveller – were it not for the fact that it’s uphill most of the way.