Philosophical
Ship of Theseus
If you replace all parts of a ship, is it still the same ship?
Overview
A thought experiment that raises the question of whether an object that has had all of its components replaced remains fundamentally the same object.
The paradox questions identity over time. If Theseus's ship has every plank replaced, one by one, is it still the same ship? What if someone builds a new ship from the old planks - which is the real Ship of Theseus?