Moderator Tom Brokaw prefaced the last question of last night’s presidential debate (offered by “Peggy of New Hampshire”) by saying it had a “certain Zen-like quality.”

The question was: “What don’t you know, and how will you learn it?”

It’s not exactly the kind of koan, or Zen question, you’d likely hear in a zendo (Famous koans are: What’s the sound of one hand clapping? If a tree falls in a forestâÂ?¦) Generally, the answer to the question is supposed to be inaccessible to the rational mind. One could easily answer Brokaw’s question rationally: “I don’t know anything about the history of World War II; I will learn it by reading books on the history of WW II.”

That aside, it’s still an interesting question.

In Zen Buddhism such question-and-answer exchanges between novices and Zen masters are called “dokusans.” Let’s see how Obama-san and McCain-san fared.

Obama answered: “The nature of the challenges that we’re going to face are immense and one of the things that we know about the presidency is that it’s never the challenges that you expect. It’s the challenges that you don’t (expect) that end up consuming most of your time.”

In other words, “I don’t know what I don’t know.”

Zen grade: A-

McCain answered: “I think what I don’t know is what all of us don’t know, and that’s what’s going to happen both here at home and abroadâÂ?¦There are challenges around the world that are new and differentâÂ?¦.So what I don’t know is what the unexpected will be.”

In other words, “I don’t know what I don’t know.”

Zen grade: A-

Both candidates then said what they do know is, they’re the best man for the job, which is why they only get an A-. There’s more than a little ego in that; also they may have dodged the question because politicians generally like to act like they know everything (until they’re subpoenaed). Ideally, there’d be a follow up question to test their knowledge. But as you can see, neither man gave an overly rational answer to the Zen question, which is why I gave them an A for effort.

UPDATE: The Takeway talks to “Peggy of New Hampshire.” Turns out she’s asked the same question of presidential candidates since the early 1990s at small-town meet-and-greets in the primarily popular Granite State. In fact, she says she asked the question of McCain in 2000; he said “it truly stumped him,” Peggy says.

“I think it’s crucial to find a question that engages them … that doesn’t allow for a facile answer,” Peggy says.

Peggy gives them both an F, by the way. “I’m not sure we learned anything,” she says. She also says she’s not a Zen Buddhist.