MU

I'm rereading Zen and The Art of Motorcycle Maintenance and had forgotten how much I love the word "mu." I remember how excited I was the first time I came across it- how satisfying it was to find that there was a word for "no thing" ...

"Because we're unaccustomed to it, we don't usually see that there's a third possible logical term equal to yes and no which is capable of expanding our understanding in an unasked direction. We don't even have a term for it, so I'll have to use the Japanese mu.

Mu means "no thing." Like "Quality" it points outside the process of dualistic discrimination. Mu simply says, "No class; not one, not zero, not yes, not no." It states that the context of the question is such that a yes or no answer is in error and should not be given. "Unask the question" is what it says."

-Robert Pirsig