" A man is in a room with a book of rules. Chinese sentences are passed under the door to him. The man looks up in his book of rules how to process the sentences. Eventually the rules tell him to copy some Chinese characters onto paper and pass the resulting Chinese sentences as a reply to the message he has received. The dialog continues."

"To follow these rules the man need not understand Chinese."

"Searle concludes from this that a computer program carrying out the rules doesn't understand Chinese either, and therefore no computer program can understand anything. He goes on to argue about biology being necessary for understanding. "