Rationality Quotes November 2012

Here's the new thread for posting quotes, with the usual rules:

Please post all quotes separately, so that they can be voted up/down separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself
Do not quote comments/posts on LW/OB
No more than 5 quotes per person per monthly thread, please.

Here's the new thread for posting quotes, with the usual rules:

Please post all quotes separately, so that they can be voted up/down separately. (If they are strongly related, reply to your own comments. If strongly ordered, then go ahead and post them together.)
Do not quote yourself
Do not quote comments/posts on LW/OB
No more than 5 quotes per person per monthly thread, please.

Previously approximated here.

I still habitually complete this joke with:

"Actually," says the stage magician, "we merely know that there exists something in Scotland which appears to be a sheep which is black on at least one side when viewed from this spot."

Though I'm now tempted to add:
"Hmph," snorts the cognitive psychologist. "Such presumption. An event occurred that we experienced as the perception of a black sheep, only one side of which was visible, standing on what we believed to be a field in Scotland."

And the biologist says, "guys, that's a dog"

10DanArmak14y

"Bah", says the thermodynamicist. "All I know is that your brain is in a configuration that makes you say you saw a black sheep a minute ago."

19A1987dM14y

I've heard a version in which after the mathematician speaks, the shepherd yells “Snowy White [the name of the sheep]! Stop rolling in the mud!”