I was reading Steven Heine’s Opening A Mountain: Koans of the Zen Masters. I really like him. He is a first rate scholar who at the same time loves koan literature and appears to be profoundly disinterested in koans as they are used within formal Zen training. What I really like is how this allows him to approach koans from left field, often offering something of genuine value to all of us, including those who do use koans as a central part of our spiritual discipline.
Anyway, early on in the book while reflecting on the origins of koans, Heine writes, “Furthermore, there is a medieval genre of detective story literature based on tales of intricate, suspenseful legal investigations that is also known by the term ‘kung-an.’ Most people in modern China who are aware of the term recognize it as referring to this literary genre, and the significance of kung-an/koan for Zen is less well known.”
I was quite taken with this, particularly as a fan of the mystery genre. While it is true that koans emerge within medieval China inspired by numerous sources, it’s unlikely the mystery genre was a major current. Still, tantalizingly, the term koan (gongan or kung-an depending on one’s preferred transliteration of the Chinese) is the same word used for Chinese medieval mysteries. But they probably both derive from the fact the term is a term of law; a koan is a “public case” as in a court case.