Logic puzzle

Six logicians finish dinner.  The waitress asks, “Do you all want coffee?”
First logician: “I don’t know.”
Second logician: “I don’t know.”
Third logician: “I don’t know.”
Fourth logician: “I don’t know.”
Fifth logician: “I don’t know.”
Sixth logician: “No.”

Who gets coffee and why?  Click “read more” for the answer.

The waitress has asked, “Do you all want coffee?”  In saying “I don’t know,” each of the first five logicians is saying, “I want coffee, and at this moment it does appear possible that all six of us do, but we don’t yet have enough information to say so definitely.”

The sixth logician doesn’t want coffee, so he’s able to say for certain that not everyone in the group does.  So the waitress serves coffee to the first five logicians.

Hat tip to the Futility Closet for the game!


Author: Kleiner

Associate Vice Provost and Assistant Professor of Philosophy at Utah State University. I teach across the curriculum, but am most interested in continental philosophy, ancient and medieval philosophy as well as Catholic thought, all of which might be summed up as an interest in the ressourcement tradition (returning in order to make progress). I also enjoy spending time thinking about liberal education and its ends.

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