The Ship of Theseus is a thought experiment about whether an object that has had all of its original components replaced remains the same object. According to legend, Theseus, the mythical Greek founder-king of Athens, had rescued the children of Athens from King Minos after slaying the minotaur and then escaped on a ship to Delos. Every year, the Athenians commemorated this legend by taking the ship on a pilgrimage to Delos to honor Apollo. The question was raised by ancient philosophers: After several centuries of maintenance, if every part of the Ship of Theseus had been replaced, one at a time, was it still the same ship?

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