Getting an education was a bit like a communicable sexual disease. It made you unsuitable for a lot of jobs and then you had the urge to pass it on.

Ankh-Morpork had dallied with many forms of government and had ended up with that form of democracy known as One Man, One Vote. The Patrician was the Man; he had the Vote.

Evolution was far more thrilling to me than the biblical account. Who would not rather be a rising ape than a falling angel? To my juvenile eyes, Darwin was proved true every day. It doesn't take much to make us flip back into monkeys again.

You never knew about people, like you never knew how deep a pond was because all you saw was the top.

What's the orbital velocity of the moon?

Once you've ruled out the impossible then whatever is left, however improbable, must be the truth. The problem lay in working out what was impossible, of course. That was the trick, all right. There was also the curious incident of the orangutan in the night-time.

They can ta'k our lives but they can never ta'k our freedom!' Now there's a battle cry not designed by a clear thinker