Theseus
The Ship of Theseus is a thought experiment about identity: if you replace every plank of a ship one by one, is it still the same ship?
The Meaning of Theseus
The Athenians preserved the ship Theseus sailed to Crete in their harbour for centuries as a sacred relic. As planks rotted, they were replaced with new timber. Plutarch asked: at what point does it cease to be Theseus's ship? If all the original planks are replaced, is it the same ship? And if you reassembled the old planks into a ship, which one is the "real" ship of Theseus? This became one of Western philosophy's foundational problems of identity, still debated in philosophy, law, and computer science.
Symbols
Fun Fact
The Ship of Theseus paradox has been used to debate everything from personal identity to patent law to the question of whether a restored building is "original."
Words We Inherited
English words and phrases that trace back to this myth. See our full guide to English words from Greek mythology.
Explore Further
Ship of Theseus
💭 conceptphilosophy
The paradox of identity: the Athenians preserved Theseus's ship by replacing rotting planks until no original wood remained.
Aporia
💭 conceptThe productive state of philosophical puzzlement
The state of intellectual impasse that Socrates deliberately induced — the recognition that you do not know what you thought you knew.
Metanoia
💭 conceptTransformative change of heart
The profound shift in understanding that occurs when someone recognises their error and fundamentally changes their outlook.
Mnēmosynē
💭 conceptmythology, philosophy
Memory personified — Titaness, mother of the nine Muses, and the principle through which knowledge and identity persist across time and death.
Philosophy
💭 conceptLanguage and thought
An English word for the study of fundamental questions about existence, knowledge, and ethics, derived from the Greek philosophia meaning love of wisdom
Symposium
💭 conceptPlato's dialogue on the nature of love
Plato's Symposium was a philosophical dialogue set at a drinking party where guests give speeches about Eros — including Aristophanes' myth that humans were once doubled beings split in two.
Nous
💭 conceptPhilosophy and Mind
The Greek concept of pure intellect or mind, the highest faculty of the soul and the organizing principle of the cosmos.
Logos
💭 conceptWord, reason, and the rational principle of the cosmos
The multifaceted Greek concept meaning word, speech, reason, account, and the rational principle governing the universe.
Plato
💭 conceptPhilosophy, myth, forms
Athenian philosopher who both critiqued traditional myths and created powerful new ones in his dialogues
Anamnesis
💭 conceptPlato's theory that learning is remembering
Plato's doctrine that the soul possesses innate knowledge from before birth, and that learning is really recollection.
Poiesis
💭 conceptphilosophy, aesthetics
Making or creation — the act of bringing something into existence that was not there before, encompassing craft, poetry, and all productive activity.
Neoplatonism
💭 conceptPhilosophy
A late antique philosophical system teaching that all reality emanates from a transcendent, ineffable One