Ship of Theseus - Wikipedia

The Ship of Theseus is a thought experiment about whether an object which has had all of its original components replaced remains the same object. … Each year, the Athenians commemorated this by taking the ship on a pilgrimage to Delos to honor Apollo. A question was raised by ancient philosophers: After several centuries of maintenance, if each individual part of the Ship of Theseus was replaced, one at a time, was it still the same ship?