First Thoughts are the everyday thoughts. Everyone has those. Second Thoughts are the thoughts you think about the way you think. People who enjoy thinking have those. Third Thoughts are thoughts that watch the world and think all by themselves. They’re rare, and often troublesome. Listening to them is part of witchcraft.

By the time you've reached your sixties, you do know that one day you will die, and knowing that is at least the beginning of wisdom.

Granddad was superstitious about books. He thought that if you had enough of them around, education leaked out, like radioactivity.

People are often so busy living that they never stop to wonder why.

One of the things forgotten about the human spirit is that while it is, in the right conditions, noble and brave and wonderful, it is also, when you get right down to it, only human.

But is all this true?" said Brutha. Didactylos shrugged. "Could be. Could be. We are here and it is now. The way I see it is, after that, everything tends towards guesswork." "You mean you don't KNOW it's true?" said Brutha. "I THINK it might be," said Didactylos. "I could be wrong. Not being certain is what being a philosopher is all about.

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.