The presence of those seeking the truth is infinitely to be preferred to the presence of those who think they've found it.

That's why it's always worth having a few philosophers around the place. One minute it's all is truth beauty and is beauty truth, and does a falling tree in the forest make a sound if there's no one there to hear it, and then just when you think they're going to start dribbling one of 'em says, incidentally, putting a thirty-foot parabolic reflector on a high place to shoot the rays of the sun at an enemy's ships would be a very interesting demonstration of optical principles.

Well, the news has got around. The Duchess of Keepsake has invited us to a ball, Sir Henry and Lady Withering have invited us to a ball, and Lord and Lady Hangfinger have invited us to... yes, a ball." "Well, that's a lot of..." "Don't you dare, Sam.

History has a habit of changing the people who think they are changing it

Most of the great triumphs and tragedies of history are caused not by people being fundamentally good or fundamentally evil, but by people being fundamentally people.

Corporal Nobbs had been disqualified from the human race for shoving

The rising sun managed to peek around the vast column of smoke that forever rose from Ankh-Morpork, City of Cities, illustrating almost up to the edge of space that smoke means progress or, at least, people setting fire to things.