One:
a physicist, a philosopher, and a mathematician are on a train bound for Omaha.
As they pass the nebraska state line, the physicist looks out the window and says "wow...Nebraska has brown cows"
the philosopher says "you still don't know that. All you know is that there is at least one cow in nebraska, and it is brown."
the mathematician says "at least one side of the cow is brown..."
Two:
An economist washes up on a desert island. After walking some distance, he happens upon a cannibal selling brains. The sign above the cannibal's brain-shack reads:
- Lawyer brains: 5$ per pound
- Doctor brains: 15$ per pound
- Economist Brains: 150$ per pound
The economist walks up and makes conversation, he can't help but show off.
"I'm an economist" he says, "and I theorize that your economist brains are so expensive because they are so highly demanded."
"well there's that." the cannibal concedes, "but do you have any idea how hard it is to get a pound of economist brains?"
Three:
During a flight, a stewardess walks up to Rene Descartes and asks, "Would you like something to drink?" the French philosopher answers, "I think not." And he disappears.
Four...i always use this when I teach dimensional analysis or certain forms of logic:
A metrics expert is sitting alone at a cafe when a waitress walks up to him.
"Can I take your order?" she asks.
"Yes," says the metrics expert, "I would like 22 grams of eggs and .202 liters of coffee with 2.5 grams of sugar and no cream."
a little while later the waitress returns.
"I'm sorry," she says, "we're all out of cream. Would you prefer to have no milk instead?"