A monk asked Joshu, “Does a dog have Buddha Nature?”
Joshu said, “No.”
The monk said, “All beings have Buddha Nature, how come the dog doesn’t?”
Joshu said, “Karmic Nature”
This is the best known of all the koans. It’s the quintessential koan. And so, it exemplifies how we misunderstand these teaching fragments.
I don’t believe the monk is really asking about a dog, or a dung beetle, or any other random thing; he’s really asking about himself: does this dog have Buddha Nature?
And Joshu says no because the monk’s framework is confused. There isn’t a fixed thing called ‘monk’ and there isn’t a fixed thing called ‘Buddha nature’, one concealed within the other. Because there are no fixed and separate things at all, there is Buddha Nature.
In most translations, such as Cleary’s, the ‘karmic nature’ is that of the dog. My teacher would say that the ‘karmic nature’ is that of the monk. That is, it’s the monk’s karma to get confused and ask questions in this way. But I like to think that Joshu is saying that it’s our karmic nature – as teacher and student, as human beings- to keep getting tangled up like this, untangling ourselves or the other, or both, getting entangled again… endless.