- Duration
- 5 min
Ship of Theseus, Digital
At what point in a gradual replacement do you stop being you?
Replace a mind, neuron by neuron, with functionally identical silicon. Mark the point where you think the original person is gone. Then compare your answer to teleportation, copying and rollback.
The experiment
The ancient puzzle asks whether a ship whose planks are replaced one at a time is still the same ship. The digital version replaces the planks with something that could not be more different in material and could not be more similar in function.
Drag the replacement forward. If you find no point at which to stop, you are treating identity as a matter of continuity — and continuity, notoriously, tolerates any change as long as it is gradual enough. If you do find a point, ask what happened there that did not happen one step earlier.
What to notice. The scenarios at the end — teleport, copy, rollback — all preserve as much as gradual replacement does, but most people judge them differently. Derek Parfit thought the discrepancy shows that identity is not what actually matters to us. See whether you agree.
Other instruments
The Mind Detector
What are you actually measuring when you decide something has a mind?
Run experimentThe Epistemic Chain
Where does responsibility for a belief live when it arrives through a machine?
Run experimentAgency Without Consciousness
Can something act for reasons with no one home?
Run experiment