Hobbes' Ship of Theseus: On the Limits of Surviving a Gradual Replacement of Parts

ABSTRACT In the ancient example of the Ship of Theseus, a ship is restored, having all its parts replaced. Ancient philosophers in Athens wondered if the restored ship was identical to the original ship. About 2000 years later, Thomas Hobbes introduced a twist; after all of the parts of the original ship had been replaced, what if the original parts of the ship had been kept and were now reassembled into a ship? If so, which ship would be identical to the original ship (if any)? In this article, I argue that if an object has all its parts replaced and all those parts are reassembled in the same structural order as the original object, then the reassembled object is identical to the original one. Moreover, in response to the original query, I argue that the original ship survives restoration in cases when its old parts are destroyed in case none of the original parts are too significant . The arguments will rely on a philosophical method that—unlike standard methods of metaphysics—depends on bottom‐up rather than top‐down intuitions, by which I mean that I will rely on intuitions about ordinary macro‐world events rather than theories that depend on intuitions about fundamental metaphysical properties.