I actually studied carefully the Koan from the Japanese Buddhist traditions a few years ago. I can't tell you much about Japanese Buddhism, but I can tell you a

I actually studied carefully the Koan from the Japanese Buddhist traditions a few years ago. I can't tell you much about Japanese Buddhism, but I can tell you a lot about the Koan. Not all Koan share all the same themes with each other, but for my money, a contemporary Koan really should try to embody all of a few important themes that I find repeated throughout the Koan. A lot of non-experts seem to want to emphasize how often someone is struck, but for me I think this comes from a one of the most interesting themes in the Koan: a sense of humor about failing to attain enlightenment. When a person attains enlightenment in the Koan, it is often at the moment when they are forced to acknowledge the duality of two opposing views, as if in the fleeting moment between seeing Rubin's Vase or the faces in its negative spaces. In that sense, at least, it is a perfect Koan.