Let's begin with the arguing monks. If we're going to make this old story relevant to our current practice, we have to begin by acknowledging that we spend most of our time behaving more like them than like either Nansen or Joshu! Even if we're not arguing out loud, our heads are filled with arguments. Arguments about what's right and wrong, true or false, fair or unfair. Thoughts of self- improvement and self-hatred. Back and forth and back and forth, we fill our heads with that endless internal dialogue.
So let's not dismiss the arguing monks too quickly, but instead let's imagine what they're arguing about. Sometimes it's said they're arguing about whether the cat has the Buddha-nature or not, but that's not one most of us can imagine getting too worked up over. I like to imagine they are arguing over the ethics of keeping a cat in a monastery. As good vegetarian Buddhists they don't want to voluntarily kill any sentient beings but mice are eating up their rice supply! Is it ethical for monks to keep a cat to do their killing for them? That might provoke a heated argument in some places even today. Now maybe we can empathize with them a little better and not just see them as foils for Nansen and Joshu.
So Nansen comes upon the argument, and what he sees is the endless back and forth and all the monks caught up in the dualism of right and wrong. Can he get them to see from another perspective? He demands they 'say a word" or he'll kill the cat. What does "say a word" mean?"
I'm reminded of a passage in one of J.R.R. Tolkien's books where Gandalf and company have come upon a enormous stone gate blocking their way through the mountains. On top of the gate is an inscription carved in some old half-forgotten language that Gandalf thinks can be translated, "Say the word, friend, and enter." So Gandalf tries every secret password and magical spell he can think of, trying to say the word that will open the giant gates. All to no avail. Then, finally, he realizes the inscription says, " Say the word 'friend' and enter." The "secret" word was written right there in front of him all along.
But none of Nansen's monks can say a word and he kills the cat. Is it fair to kill a living creature just to make dramatic point? A fair question, but one that will toss you right back into the midst of the monks' original argument.
That night when Nansen tells Joshu what happened, Joshu immediately puts his sandals on his head and walks out. What do you make of that? How is putting your sandals on your head "saying a word" of Zen? The danger here, of course, is if we think Joshu's gesture has some deep, esoteric "Zen" meaning. People have interpreted that gesture in all sorts of ways. Some say it's a way of illustrating how topsy-turvy the arguing monks thinking was. In Aitken Roshi's commentary on the case, he says that in old China putting your sandals on your head could be a show of mourning. Maybe a Catholic would automatically make the sign of the cross when hearing about a death. Whatever it "means," it was simply Joshu's spontaneous response to the story, and the immediacy of that response stands in stark contrast to the monks (who up until then had no shortage of words) standing around speechless when asked to "say a word".
Traditionally, Nansen and Joshu are said to each wield a sword: Nansen the sword that kills; Joshu the sword that gives life. Nansen's sword cuts through all thought, all dualism. Nothing is left. What then? Joshu shows how we must respond from that place of no thought. It's not enough to empty our heads of dualistic thinking, we must act.
One of the things I like about beginning sesshin by chanting the Heart Sutra and the Sandoki in their Sino-Japanese versions, as well as in English, is the way that makes us concentrate on them as pure sound. You must concentrate fully on just making a sound, with no room for any thought about what it means. If you think about it, you're lost. With all our attention on those "nonsense" syllables, there's no room for a thought in our heads. And yet our attention is sharp and we chant vigorously and in unison. Our whole day needs to be like that. We label our thoughts as "thought" and see them as the background noise of old monks arguing, arguing. We come back, without thought, to awareness of breath and body and of all the sounds that penetrate the zendo. But we can't disappear into that "thoughtless" place - at any moment we have to be prepared to act, to pay attention to how we bow, how we walk, how we do oryoki or our work assignments. We must be ready to "say a word."