The big idea: Over a lifetime your body swaps out most of its cells, your beliefs shift, your memories fade. If everything is replaced, in what sense are you still the same person? This is the puzzle of identity over time.
Imagine: the ship of Theseus: A wooden ship has its rotten planks replaced one by one. After years, every plank is new. Same ship, or a different one?
Swap 'ship' for 'you': your body replaces its parts too. If the ship might not survive a full rebuild, do you?
Free preview
This is the free notes preview
You're reading the free notes. Aimnova Pro unlocks the full study experience — and you can try it free for 7 days:
- FlashcardsLock in vocabulary and key terms with spaced repetition.
- Practice questionsAnswer exam-style questions and get instant AI marking.
- Mock exams & past-paper vaultSit full mocks and see exactly how examiners award marks.
- Personalised study planA daily plan built around your exam date and weak areas.
Start your 7-day free trial Full access to Aimnova Pro · cancel anytime
A sharper version pushes even harder on what 'staying the same' means.
Imagine: the teleporter: A machine scans every atom of your body, destroys the original, and builds an exact copy on Mars from new atoms. The copy walks out sure it is you.
Did you travel — or did you die, and a copy now lives your life?
"You survived"
- What matters is the pattern, not the atoms
- The copy continues your mental life
- We already replace atoms slowly
"You died"
- Your original body was destroyed
- A copy is only qualitatively identical
- Make two copies — they can't both be you
Go further — higher-level insight: The 'two copies' move is the killer objection to pattern-based survival: if the machine builds two perfect copies, neither has a better claim to be you, yet numerical identity can't split. Keep this in reserve for a top-band paragraph.