What makes you, you · Quiz question 15/35

The Brain Transplant

The Brain Transplant (Brown–Brownson Case)

Your brain goes into someone else's body. Is the person who wakes up you? From Locke's prince and cobbler to Shoemaker's Brownson case.

As it appears in the quiz

Surgeons successfully move your brain into someone else's body. The new body talks with your memories; your old body is on life support with no brain.

The person who wakes up in the new body is me.

Who came up with it

The prototype is John Locke's "prince and the cobbler," added to the 2nd edition of the Essay (1694): if the prince's soul and consciousness moved into the cobbler's body, that person would think of himself as the prince and be accountable for the prince's actions. The modern version is American philosopher Sydney Shoemaker's 1963 Brown–Brownson case: Brown's brain is put into Robinson's body, and the resulting "Brownson" has Brown's memories and personality — we'd judge him to be Brown.

Original papers & key readings

What it's really asking

A brain transplant looks like the sharpest split between psychological and bodily criteria. Interestingly, bodily theorists split here too: if you treat the brain as the key "body part" for identity, a bodily theorist can also say the person in the new body is you.

The most challenging answer comes from animalists. Eric Olson says that even here you stay with the original body on life support — the original human organism — as long as the brainstem keeps its life functions going. Most people find that wildly counterintuitive, but Olson accepts it as the price of being an animal. This question shows most sharply whether you see "you" as a stream of thought or as a living body.

Where philosophers stand

Psychological continuity (agrees)

Where your memories and personality go, you go.

Key names: John Locke, Shoemaker, Derek Parfit

Brain-based view (agrees)

The body part that carries your identity is the brain. Where it goes, you go.

Key names: Thomas Nagel (The View from Nowhere, 1986), Jeff McMahan

Animalism (disagrees)

You're an organism. Even if the brain leaves, the original body whose life continues is you.

Key names: Eric Olson

Philosophers to check out

Sources