The robe is black, with a rope around the waist and fabric that drapes voluminously through the sleeves. So now, as Mike Zimmerman stands before his teacher and prepares to sit, he must arrange the robe just so, folding and tucking and folding some more.

He once was chief justice of the Utah Supreme Court. In those days he wore a different black robe, but that was then and this is now, and, as any Buddhist knows, then is not so important. In those days he sat on the bench. Now he is sitting, cross-legged, on the floor.

In his deep, serious voice he begins: "Goso said, 'To give an example, it is like a buffalo passing through a window. The head, the horns and the four legs have already passed through, but the tail has not. Why is it that the tail cannot?"

In Zen Buddhism, this is called a koan — the kind of inscrutable paradox most famously expressed in the question "What is the sound of one hand clapping?" There are hundreds of koans, and according to the Zen masters it's impossible to figure them out intellectually, the way you might an algebra problem or a riddle. To really solve a koan, they say, it is necessary to be the koan. Koan work, they say, is a lifetime process.

His teacher sits on a mat in front of him as Zimmerman begins his answer, an answer that takes into account the symbolism of the buffalo, and the possibility of the relative and absolute both existing simultaneously. "You're on the right track," says his teacher. "But there's a very subtle thing that's eluding you."

So Zimmerman begins again, noting that it is impossible to separate personal liberation from the liberation of all sentient beings. Yes, says his teacher, but there is one more thing.

"Where are we going if we go through the window?" the teacher asks.

"Outside."

"Where is outside? Is there such a thing?"

"No."

"If we're going outside the window, the whole thing is dualistic," says the teacher, a cheerful man named Daniel Silberberg. "But the place the buffalo and the tail are is right here. Wherever we're going, we're going together, and wherever we're going, we're already there."

Zimmerman rises and straightens out his robe. It is 7 a.m. There is no outside, but he goes there anyway. He drives home. He puts on a suit and tie. He drives to work. He retired from the Utah Supreme Court in 2000, and now he is a lawyer. A Zen Buddhist monk who is also a partner in the firm of Snell & Wilmer.