[Parfit](derek-parfit.md) laid out three arguments against [[endurantism]] in his piece "Identity," aka his theory of survival. First argument from fission thought experiment: (1) Remaining one and the same thing over time is a relation which is one-one (2) What matters for survival is a relation which is one-many So (3) what matters for survival isn't remaining one and the same thing over time Second argument from fusion thought experiment: (1) Remaining one and the same thing over time is a relation which is all-or-nothing (2) What matters for survival is a relation which admits of degree So (3) what matters for survival isn't remaining one and the same thing over time Third argument from eternal being thought experiment: (1) Remaining one and the same thing over time is a relation which is transitive (2) What matters for survival is a relation which is non-transitive So (3) what matters for survival isn't remaining one and the same thing over time In summary: Endurantism is characterized by Parfit as one-one, all or nothing, and transitive. Parfit's [[perdurantism]] is contrary to that by being one-many, admits of degree, and non-transitive. Up: [[metaphysics]]