Nan-in's Tea Cup
A university professor visited Nan-in to inquire about Zen.
Nan-in served tea. He poured his visitor's cup full, and then kept on pouring.
The professor watched the overflow until he could no longer restrain himself. "
It is overfull. No more will go in!" "Like this cup," Nan-in said,
"you are full of your own opinions and speculations.
How can I show you Zen unless you first empty your cup?"
Reflection
Nan-in's teacup parable repeats the teaching of emptying the cup of preconceptions. The professor's overflowing cup is a vivid image of the mind closed by its own knowledge. The koan is a universal reminder that all genuine learning requires an open, receptive state. The cup must be empty to receive; the mind must be empty to see clearly.