ship of theseus, or theseus's paradox

• origin: plutarch, life of theseus, late first century
• variants: grandfather's axe
• noted philosophers: heraclitus, plato, thomas hobbes, john locke

the ship of theseus is a thought experiment that raises the question of whether an object that has had all of its components replaced remains fundamentally the same object.

• plutarch asked whether a ship that had been restored by replacing every single wooden part remained the same ship

original version

— the ship wherein theseus and the youth of athens returned from crete had thirty oars, and was preserved by the athenians down even to the time of demetrius phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their places, in so much that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same... —