Achilles and the Tortoise on Koans

:

Achilles: My pleasure. I can tell you a pair of kōans which go together. Only …

Tortoise: What's the matter?

Achilles: Well, there is one problem. Although both are widely told kōans, my master has cautioned me that only one of them is genuine. And what is more, he does not know which one is genuine, and which one is a fraud.

Tortoise: Crazy! Why don't you tell them both to me and we can speculate to our hearts' content!

Achilles: All right. One of the alleged kōans goes like this:

A monk asked Baso: “What is Buddha?”

Baso said: “This mind is Buddha.”

Tortoise: Hmm … “This mind is Buddha”? Sometimes I don't quite understand what these Zen people are getting at.

Achilles: You might prefer the other alleged kōan then.

Tortoise: How does it run?

Achilles: Like this:

A monk asked Baso: “What is Buddha?”

Baso said: “This mind is not Buddha.”

Tortoise: My, my! If my shell isn't green and not green! I like that!

Achilles: Now, Mr. T—you're not supposed to just “like” kōans.

Tortoise: Very well, then—I don't like it.

:

When I originally read this dialogue, I assumed Hofstadter was just inverting a legitimate koan to make a point, but it turns out it isn't so: the two koans really are both widely told, and in fact both appear in Zen Flesh Zen Bones. This makes the whole thing even more amusing.