A university professor visits the Zen teacher Nan-in. As tea is poured beyond the cup’s capacity, the overflowing cup becomes an image for a mind so full of opinions that it cannot receive instruction.
Source and historical status
The story is widely circulated in twentieth-century Zen literature. It should not be confused with an ancient Buddhist sutta or treated as a verbatim historical transcript.
The narrative in context
A university professor visits the Zen teacher Nan-in. As tea is poured beyond the cup’s capacity, the overflowing cup becomes an image for a mind so full of opinions that it cannot receive instruction.
What the story teaches
The anecdote is used to teach beginner’s mind, humility, and openness in learning.
How to read the overflowing-teacup anecdote
The Nan-in teacup story became widely known through modern Zen literature, and its exact wording varies across retellings. It is better treated as a teaching anecdote attributed to a modern Zen master than as an ancient kōan or verbatim transcript. Its enduring value comes from the image of intellectual overfilling and the need for openness in learning.
