A man who speaks no Chinese can answer questions in Chinese using only a rulebook

Imagine someone locked in a room with a rulebook that tells them exactly which Chinese symbols to output for any symbols slipped under the door, producing flawless replies without understanding a single word. John Searle used this thought experiment to argue a computer, like the man, might perfectly simulate understanding through symbol manipulation while genuinely understanding nothing at all.

— John Searle, Minds, Brains, and Programs — Behavioral and Brain Sciences, 1980