William: "I'm sure we can all pull together, sir." Vetinari: "Oh, I do hope not. Pulling together is the aim of despotism and tyranny. Free men pull in all kinds of directions.

Imagination is only intelligence having fun. A healthy mind knows how to switch between worlds, and which one you need to eat and sleep in.

It was the heart of any scam or fiddle -- keep the punter uncertain, or, if he is certain, make him certain of the wrong thing.

I don’t think it's weak to admit you made a mistake. That takes strength, if you ask me.

After a while, another voice said: One, two, three, four- And the universe came into being. It was wrong to call it a big bang. That would just be noise, and all that noise could create is more noise and a cosmos full of random particles. Matter exploded into being, apparently as chaos, but in fact as a chord. The ultimate power chord.

The merest accident of microgeography had meant that the first man to hear the voice of Om, and who gave Om his view of humans, was a shepherd and not a goatherd. They have quite different ways of looking at the world, and the whole of history might have been different. For sheep are stupid, and have to be driven. But goats are intelligent, and need to be led.

The Library didn't only contain magical books, the ones which are chained to their shelves and are very dangerous. It also contained perfectly ordinary books, printed on commonplace paper in mundane ink. It would be a mistake to think that they weren't also dangerous, just because reading them didn't make fireworks go off in the sky. Reading them sometimes did the more dangeous trick of making fireworks go off in the privacy of the reader's brain.