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Can you solve the famously difficult green-eyed logic puzzle? - Alex Gendler


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TEDEd Animation

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One hundred green-eyed logicians have been imprisoned on an island by a mad dictator. Their only hope for freedom lies in the answer to one famously difficult logic puzzle. Can you solve it? Alex Gendler walks us through this green-eyed riddle.

Additional Resources for you to Explore

See a couple of different formulations of the puzzle here, here, and here, along with discussions that show why the precise details of the puzzle setup make a huge difference. Read more about common knowledge at the Stanford Encyclopedia of Philosophy, or check out David Lewis’s original book: Convention: A Philosophical Study on the subject. To see how the concept can apply to economics and game theory, take a look at the work of Robert Aumann, Shyam Sunder, and John Allen Paulos.

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Meet The Creators

  • Educator Alex Gendler
  • Director Outis
  • Narrator Addison Anderson

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