Classmate JJ Snidow told me this joke, but it was supposedly an actual exchange between Oxford Philosophy of Language Professor J.L. Austin and Columbia philosopher Sidney Morgenbesser (who was apparently the man?)
“In English,” Professor Austin said, “a double negative forms a positive. However, in some languages, such as Russian, a double negative remains a negative. But there isn’t a single language, not one, in which a double positive can express a negative.”
A voice from the back of the room piped up, “Yeah, right.”
Isn’t linguistics funny?