There are no inconsistencies in the Discworld books; ocassionally, however, there are alternate pasts.

I write books back to back, and I work very hard on them.

So let's not get frightened when the children read fantasy. It's the compost for a healthy mind. It stimulate s the inquisitive nodes, and there is some evidence that a rich internal fantasy life is as good and necessary for a child as healthy soil is for a plant, for much the same reasons.

The trouble is you can shut your eyes but you can’t shut your mind.

In defiance of Miss Maccalariat I'd like to commit hanky-panky with you, Miss Adora Belle Dearheart... well, certainly hanky, and possibly panky when we get to know one another better.

It as true that normal people couldn't hear Gaspode speak, because dogs don't speak. It's a well know fact. ... Besides, almost all dogs don't talk. Ones that do are merely a statistical error, and can therefore be ignored.

When all else failed, she tried being reasonable.