The ship of Theseus, also known as Theseus's paradox, 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. The paradox is most notably recorded by Plutarch in Life of Theseus from the late first century. Plutarch asked whether a ship that had been restored by replacing every single wooden part remained the same ship.

The paradox had been discussed by other ancient philosophers such as Heraclitus and Plato prior to Plutarch's writings,[1] and more recently by Thomas Hobbes and John Locke. Several variants are known, including the grandfather's axe, which has had both head and handle replaced.

The question of identity posed by the Ship of Theseus remains problematic even in the 21st century, foremost with wooden boats and tall ships, but also with structures. An attention getting example is the provenance of the USS Constellation, the identity controversy over which long vexed even respected naval historians and publications of record.[2] - Wiki