Case 1 of the Mumonkan goes like this:
A monk asked Joshu, “Has a dog the Buddha nature?” Joshu replied, “Mu.”
That’s it. A monk asks a question. Joshu gives him one word.
The question comes from a traditional Buddhist teaching: all sentient beings have Buddha nature. A dog is a sentient being, so perhaps the expected answer would be yes. Instead, Joshu says Mu.
In Japanese, mu can mean “no” or “not”, but treating it simply as Joshu’s answer to the monk’s question doesn’t get us very far. If the answer were simply no, there wouldn’t be much of a kōan left to practise with.
So what do we do with Mu?
I’ve been practising with Mu for some time, and every time I return to it, it brings up something new. It works on you. Or maybe it wears something away.
I recognise something of myself in the monk’s question. I like to understand things. I studied philosophy, and I’ve always had a tendency to analyse, explain and try to make sense of things. There is nothing wrong with that. Thinking is useful. Asking questions is useful. Sometimes we actually need an answer.
But Mu doesn’t seem particularly interested in giving me one.
I can read commentaries about it. I can study what different teachers have said. I can learn about Buddha nature, emptiness and the history of the kōan. All of that may be interesting and useful.
And then the monk asks:
“Has a dog the Buddha nature?”
Mu.
Back to the beginning.
When practising with Mu in meditation, there is always the temptation to turn it into another object of thought. What does it mean? What am I supposed to experience? Am I doing it correctly? What should happen next?
Before long, Mu has acquired an entire committee.
And yet there is still only Mu.
Perhaps this is one reason the kōan continues to interest me. I can’t think my way to the end of it. Every explanation I produce eventually becomes another thing I can look at, question and put aside.
Mu remains.
There is a saying: “There is only one big Mu in the entire universe.”
How would you express that?
I don’t know.
And saying “I don’t know” doesn’t solve it either.
I can take Mu with me onto the cushion. It can appear while I’m walking, cycling, eating or working. Sometimes it is very present. Sometimes I forget about it completely. Sometimes I find myself constructing another beautiful explanation of what Mu really means.
And sooner or later I notice what I’m doing.
Mu.
What I increasingly appreciate about this kōan is that it doesn’t require me to settle the matter. I don’t have to produce a theory about Joshu, the monk, the dog or Buddha nature.
The question can remain a question.
After all the commentaries, explanations, meditation, philosophy and attempts to understand, Case 1 of the Mumonkan is still remarkably short.
A monk asked Joshu, “Has a dog the Buddha nature?”
Joshu replied:
“Mu.”
