“A knowledgeable fool is a greater fool than an ignorant one.”

Molière [e-mailed by a friend without further citation]

“‘The optimist goes to the window and says, “Good morning, God.” The pessimist goes to the window and says, “Good God, morning.”‘

“T.J. Park, Oshawa, Ont.” quoted in “Smile” in Globe & Mail September 5, 2001

“doctors joke about a test for insanity: Put someone in a room with an overflowing sink and a mop. And then see if he tries to mop up the mess - or just turns off the tap.”

Peter Brimelow in National Review April 7, 1997

“He who knows others is learned; he who knows himself is wise.”

Lao-Tzu [e-mailed by a friend without further attribution]

“A pessimist is one who has been intimately acquainted with an optimist.”

Elbert Hubbard, quoted in “Social Studies” in Globe & Mail Sept. 13, 2004

Suzanne: “Rob, don’t talk to me when I’m at my wits’ end."
Rob (to Tina): "… Is Suzanne ever at her wits’ beginning?”
Tina: “It’s a very narrow window of opportunity…"

“Tina’s Groove” comic strip in Ottawa Citizen March 9, 2004

“the sanest of all human impulses, the impulse that bids us put our trust in industry and a defined aim.”

G.K. Chesterton, “Lunacy and Letters,” in Alberto Manguel, ed., On Lying in Bed and Other Essays by G.K. Chesterton

“It is not enough to have a good mind. The main thing is to use it well.”

Réné Descartes, Discours de la Méthode (I’ve seen it variously translated; the original is “Ce n'est pas assez d'avoir l'esprit bon, mais le principal est de l'appliquer bien.”)