Damascene Philosophy

Thought ExperimentsXII

Could you upload your mind?

If every connection in your brain were scanned and run on a computer, would the program be you, a copy of you, or no one at all?

Reading time
4 min
Difficulty
Intermediate
Branch
Identity
First posed
Science fiction from the 1950s onward; philosophical treatment by Hans Moravec, 1988, and David Chalmers, 2010
scanbiological brainemulation
Copy a brain's structure neuron by neuron and run it on a computer. Would the person come along?

The setup

Your brain contains roughly 86 billion neurons connected by perhaps 100 trillion synapses. Suppose that, in the future, a scanner could record the structure and state of every one of them, and a computer could simulate the whole thing in real time. The simulated brain is given a virtual body in a virtual world, or a robotic body in this one.

The simulation wakes. It speaks in your voice, recalls your childhood, worries about your unfinished projects, and loves the people you love. It says: 'It worked. I'm still here.'

Is it right? Mind uploading combines two of philosophy's hardest questions. First, would the simulation be conscious at all, or would it be a perfect imitation with no one home? See machine consciousness. Second, even if it were conscious, would it be you, or a new person who believes they are you? See the teleporter.

Why it matters

Some people see uploading as a path to immortality, and some research groups have begun mapping the complete wiring of small brains, such as the fruit fly connectome published in 2024. Whether uploading would preserve you or merely produce a copy is the central question for anyone who would consider it.

Even if uploading is never possible, the thought experiment clarifies what you think you are: a body, a pattern of information, or something else.

Key terms

  • Whole brain emulationThe hypothetical copying of a particular brain's structure in enough detail to run it as software, reproducing its behaviour.
  • Substrate independenceThe assumption that a mind depends on the pattern of information processing, not on the material it runs on, so a mind could exist in silicon as well as in neurons.
  • Psychological continuityOverlapping chains of memories, intentions, beliefs and character linking a person at different times. Many theories of personal identity are built on it.
  • Pattern identityThe view that a person is a pattern of information, so that whatever carries the same pattern, in any material, is that person.

The positions

Position I

Uploading would be survival

You are a pattern of information. If the pattern is preserved and continues to run, you survive, whatever it runs on.

Position II

Uploading would be death

An upload, even if conscious, would be a different person. You would die and be replaced by a digital twin.

Position III

There would be no one there

A simulation of a brain would not be conscious at all. Uploading would produce an elaborate puppet, not a person.

Arguments and objections

Uploading would be survival

Best argument
Your atoms are constantly replaced; what persists is the pattern of organisation. If that pattern is copied exactly and continues on another substrate, everything that makes you you continues. Hans Moravec and others argued that a gradual upload, replacing neurons with artificial ones one at a time while you stay conscious, would make the continuity especially clear.
Strongest objection
If the scan is non-destructive, there will be two of you: the original, still in a biological body, and the upload. The original will feel no different and will clearly not have moved into the computer. So uploading creates a copy, not a transfer.
The reply
Pattern theorists answer, with Derek Parfit, that in that case both have what matters in survival, and that the gradual method avoids the problem by never creating a duplicate.

Uploading would be death

Best argument
Identity requires physical continuity of the brain, or of the organism. A computer running a simulation is a different physical object. The duplication problem shows that copying is never moving: if the copy were you, then two copies would both be you, which is impossible.
Strongest objection
If gradual replacement of neurons with silicon would preserve you, as many think, it is hard to see why a fast replacement would not. And your neurons' atoms are replaced over time anyway.

There would be no one there

Best argument
A simulation of a hurricane does not make anything wet. On biological naturalism, consciousness depends on biological causal powers, not on information processing. A simulated brain would behave as you do but feel nothing.
Strongest objection
If behaviour, reports and internal organisation are all exactly as in a conscious person, the claim that there is no experience seems impossible to test, and possibly to state clearly.

Who argued what

  • Uploading would be survival Hans Moravec, Ray Kurzweil, David Chalmers
  • Uploading would be death Eric Olson, Susan Schneider
  • There would be no one there John Searle

Where you stand

Where do you stand?

Choose one to see how people answer.

Variations

Gradual uploading

Each night, while you sleep, nanobots replace one percent of your neurons with functionally identical artificial ones. After a hundred nights, your brain is entirely artificial. At no point did you notice anything. Did you survive? If yes, what about the same process done in a single night? In a single second?

Two uploads

Your upload is so successful that the company runs two copies. They diverge after a day: one takes up painting, the other mathematics. Which is you? If neither, was the single upload ever you?

Go deeper

How close are we?

In 2024, the FlyWire consortium published a complete wiring diagram of the brain of an adult fruit fly, with about 140,000 neurons and around 50 million synapses. A human brain has roughly 600,000 times as many neurons. And a wiring diagram is not a working model: it leaves out the strength and chemistry of connections, the role of glial cells, and the dynamic state of the living brain. Most neuroscientists consider human uploading, if possible at all, to be far in the future.

Related ideas

Thought experiment

Would you step into the teleporter?

It scans you, destroys your body, and builds a perfect copy on Mars a moment later. The copy wakes up remembering stepping in. Did you travel, or did you die?

Question

Could a machine be conscious?

Machines can now talk, reason and seem to care. Whether anyone is home inside them is a different question, and no one knows how to answer it.

Question

Are you the same person you were at eight?

Almost every cell, belief and memory has changed. Something makes that child you. The question is what.

Thought experiment

The Ship of Theseus

Replace a ship's planks one at a time until none of the originals remain. Is it the same ship? And if someone builds a second ship from the old planks, which one is the original?

Thought experiment

The Chinese room

A man in a room follows a rulebook to answer questions in Chinese perfectly, without understanding a word. Is that all a computer ever does?

Question

Should we fear death?

Epicurus argued that death is nothing to us: when it comes, we are gone. Few have found the argument convincing, and fewer have refuted it.

Further reading and sources

Open questions

  • If you are a pattern, where exactly is the pattern?
  • Would you upload if it meant your biological self would keep living separately?
  • If an upload of a loved one spoke to you, would you grieve for them anyway?

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