If a machine copied you atom by atom, would the copy be you?
A philosopher argued the question has no answer, and that this is good news. Believing it, he said, felt liberating.
▶ Start the storyPhilosophers split, and the most famous modern answer is that the question may have no fact to settle it. The British philosopher Derek Parfit imagined a teleporter, straight out of Star Trek, that scans you, destroys you on Earth, beams your information to Mars at the speed of light and rebuilds you there atom by atom. The person on Mars remembers your morning and feels like you. Is that you who travelled, or did you die and get replaced?
Step 1: Scan
You're put to sleep and every atom is recorded
Step 2: Destroy
Your body on Earth is broken down
Step 3: Send
The information travels to Mars at light speed
Step 4: Rebuild
A machine on Mars recreates you, memories and all
Step 5: Is it you?
And what if the original was never destroyed?
Common sense offers two candidates for what makes you you. One is your body, but bodies keep swapping out their matter as they age and grow. The other, defended by John Locke in 1689, is your consciousness and memory. Parfit's machine breaks both. Then he upgrades it: the original isn't destroyed, and the machine can print several copies, each one sure it is the real you. They can't all be you, and nothing about the atoms or the memories picks a winner.
Parfit's conclusion was radical. He argued there is no further fact about identity beyond the physical and psychological facts, so the question "will it be me?" need not have an answer. What really matters, he said, is the chain of memory and character, which he called Relation R, not identity itself.
He found this freeing. Before, his life had felt like a glass tunnel heading toward darkness; afterward, he wrote, "I now live in the open air", less worried about his own future and more concerned with other people's.
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Recap
For Parfit, what matters in survival is the chain of memory and character, not identity itself.
Surprising fact · Parfit argued there may be no fact about whether a teleported copy is you, and that identity isn't what matters.
Sources (4)
No source, no claim. Every fact in this lesson (28 claims) cites at least one of these.