# Ship of Theseus **Domain:** Metaphysics / Persistence / Replacement **Doc Type:** Thought-Experiment Node **Classification:** Gradual-Change Identity Test **Maturity:** Foundational **Related:** [[wiki/Migration Right|Migration Right]], [[wiki/Durable Identity|Durable Identity]], [[wiki/Substrate Transition|Substrate Transition]] --- ## The Puzzle The **Ship of Theseus** asks whether an object remains the same when its components are replaced one by one. A stronger Hobbesian variant reconstructs a second ship from the discarded original planks, forcing a choice between continuity of organization and continuity of matter. ## Continuity Application Gradual neural replacement is often treated as intuitively safer than destructive copying because causal and functional organization never ceases. The ship puzzle shows why this supports an intuition without proving it. If removed biological components could also be reassembled, organization and material lineage would point to different successors. ## Decision Consequence Migration policy should record replacement sequence, causal continuity, retained material, interruptions and branching possibilities. Gradualness is evidence, not a metaphysical solvent. It may reduce operational discontinuity while leaving consciousness and numerical identity unsettled. ## Sources - Plutarch, *Life of Theseus*, section 23. - [Stanford Encyclopedia of Philosophy — Ordinary Objects, Ship of Theseus note](https://plato.stanford.edu/entries/ordinary-objects/notes.html) ## See Also [[wiki/Teletransportation Paradox|Teletransportation Paradox]] · [[wiki/Fission and Fusion of Persons|Fission and Fusion of Persons]] · [[wiki/Substrate Independence|Substrate Independence]]