I've heard that when humans become able to upload their brains to a computer, it would realize the dream of immortality... why?

Let's suppose that I upload my brain to my computer and then transfer it to a robot.

This robot will act like me, have my memories, my personality and so on. Now imagine that this robot dies (on a airplane crash or however) - it's ok, I'm fine, it was the robot, not me.

Now let's invert the scenario: I die on a airplane crash and the robot is in my house. I'm dead. What will live in my place will be the robot with my memories and all, and not me.

This doesn't seem to be immortality for me, but for the people who knew me, since the only perceptible difference between me and the robot is only that his body is made of metal (maybe no difference, I've read that they are testing printing organs).

In my opinion, immortality would be true in this way only if we were able to transfer our consciousness to the "fake" body.

That said, why is brain uploading taken to be immortality?

  • $\begingroup$ In a way, this sort of thing is already happening. The people who know you best can imagine conversations with you, and will be able to find out what you would say without ever talking to you. They know how you will act without having to see it. If you pass on, you're not really gone until everyone who ever knew you has passed on. Maybe not even then if you were especially memorable, and they pass on what they knew about you. $\endgroup$ Commented Apr 29, 2016 at 1:42
  • $\begingroup$ Reminds me about a horror game 'Soma'. Very well made. $\endgroup$
    – Exerion
    Commented Apr 29, 2016 at 8:20
  • $\begingroup$ Let's say that we are speaking about a software that has hardcoded optimizations for a specific hardware. An artificial body is not an atom by atom copy of your own body so your personality won't evolve the same from the point it starts to operate in the new body. I understood where you want to go with your question but a better example would be the teleportation ones from the answers. For example, if your artificial body cannot get ill then your evolution chances are completely different. I would not consider the copy the same person. $\endgroup$ Commented Apr 29, 2016 at 12:40
  • $\begingroup$ What about the you before the copy is made? From his point of view it's win-win he gets to live into 2 branches. The 2 versions of him might end up hating each other or not caring about each other but the version of him before the copying can be sure that there will be 2 separate future selves which look back on it and as such it's got a much better chance at survival long term. It's only after the copying that both will look at the other and say "that's not really me" $\endgroup$
    – Murphy
    Commented Apr 29, 2016 at 15:45
  • $\begingroup$ Consider an early version of Star Trek's teleportation. The machine analyzes your atoms, transmits the information to a machine at the other end, which creates another you based on that information. The new you then signals back "I'm here!", and you say "Great!" and then press the button to kill your original body. Would you accept that the person at the other end is the real you? Would you willingly kill yourself? Your only loss would be the three word conversation. The people on Star Trek effectively do this all the time without even thinking about it. So think about it. $\endgroup$ Commented Mar 12, 2019 at 12:44

9 Answers 9


Most who explore the idea of a brain upload as immortality push hard against your intuition of what your 'self' is. You think you're pretty darn sure what your self is, but it's actually a very slippery concept. For example, do you think you can define your "self" as your body? Many of the atoms in your body are changed out rather rapidly. While tooth enamel and some of the crystals in the lens of your eye show very low rates of replacement, a large portion of the body is made of brand new atoms every year!

Which brings up the Ship of Theseus. The Ship of Theseus is the most famous thought experiment on this topic:

The ship wherein Theseus and the youth of Athens returned from Crete had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their places, in so much that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same.
— Plutarch, Theseus

In this story, we start with a famous ship, the Ship of Theseus himself. The Athenians loved that ship so much that they kept it maintained for hundreds of years. Whenever a plank got too worn out and decayed, they'd replace it to keep the ship in prime condition. At some point, every single piece of wood was replaced this way, so there were no original boards left from Theseus's time. The question raise is in three parts:

  • Is this the same ship that Theseus sailed on?
  • If so, why? There's not a single board in common between the ship Theseus used and the one described here. How can we call it the "same?"
  • If not so, then at what point did it cease to be the same ship?

Philosophically, this is an unsolved question. It seems like it should be intuitively easy, but every line of logic which philosophers have gone down ends in an uncomfortable conclusion. Identity is not as simple as we think.

Another famous question pulling at these threads is a problem involving teleportation between planets. Let's say we develop a way to teleport between planets. However, there's a catch. It's not actually moving matter from one planet to another. That would take too much energy. Instead, the "teleporter" reads the state of your body, the position of every atom, every electric field, from your head to your toes. This information is transmitted to the other planet, where they create a new "you" with exactly the same properties in every way.

This obviously isn't "teleportation," its "cloning." However, what if we destroy the original after we create the copy on the other planet? Now we still have one body, and it has every hope, dream, memory, and desire that the original did. Is this not teleportation of your "self?" If it isn't, consider how hard it is to tell the difference between that and a really fast rocket ship flight empirically. The only difference would be which atoms make up the entity on the other planet, and we've already shown that's a hazy definition of "self" at best.

Now this sounds like a dangerous teleporter. What happens if something goes wrong during the reconstruction? Now you're dead. So let's put a safeguard in. The original is not destroyed until the teleporter on the other planet sends a confirmation that, indeed, the other body is complete. Now let's say the safeguards fail. Now there are two "you's" walking around on different planets, living potentially different lives. We would generally consider the "you" on Earth to be the "original," and the "you" on the other planet to be the "clone" because your Earthbound body was constructed before the clone body on the other planet.

I think this is very close to your argument. Your argument is that the body you inhabit right now is the "original" you, and the robot is a clone. This is very normal. Now let's make the intuition harder. Let's say that, instead of malfunctioning and leaving the body on Earth, it instead sent out two clones: one to Mars one to Venus. The construction of the new body/bodies completed, so the Earth teleporter destroys the old body. Now which one is the clone, which one is the original? Is it the one on Mars, or the one on Venus?

There are no universally accepted answers to these questions. These are philosophical questions that have persisted for thousands of years, and will likely continue for thousands more. However, one thought process to consider:

You gave examples from the perspective of the biological "you," but remember that your robot clone has all the same hopes, memories, dreams, and desires that you do. So how would the robot feel, being in a plane crash. Would he be comforted to know that the "real" you is still alive? If instead, your biological body died in an airplane crash. Would the robot feel any less lucky that it wasn't in the airplane crash? How much actual difference is there between the biological you and the robot you?

I leave with two parting stories. First is Valery Spiridonov, who has requested to be the first human to undergo a full-body transplant. Suffering from terminal muscular atrophy, he intends to have his head cut off and sewn onto the donor body of a brain dead organ donor. How different is this from being implanted in a robot?

The second story is the curious case of Krista and Tatiana Hogan, Conjoined twins joined in the skull (craniopagus). They are a fascinating topic for researchers trying to figure out if they are one consciousness or two. Sometimes they act like independent beings, doing their own thing. Other times, they act so extraordinarily in unison that you have to wonder if there's really just one consciousness controlling the whole body.

These are cases where the easy versions of "self" break down. And, indeed, brain uploads are one such example where the easy versions just get... complicated.

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    $\begingroup$ Great answer, but you skipped my favourite question on Theseus. While you were busy replacing all of the boards, I was pilfering your rubbish heap. I took every board and nail, then reconstructed the original with the original pieces. Which one is the 'real' Ship of Theseus? $\endgroup$ Commented Apr 29, 2016 at 4:01
  • $\begingroup$ Personally I find the idea of being cut & pasted like a file through different filesystems a scary idea (copy content, then delete source). I would never try out teleportation until they tell me I'm just going through a worm hole and the matter that get to the destination is the same that parted from my current location. $\endgroup$ Commented Apr 29, 2016 at 12:31
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    $\begingroup$ @JoelHarmon, neither. One is a cheap replica for the tourists, the other is a rotten hulk. But frankly, as long as the tourists pay to see it, and think it's Theseus's ship, and as long as you pay me for rusty nails thinking you get the "true Theseus'" ship, who cares? Theseus' ship is gone, just like your 5-year-old self. Nobody cares. $\endgroup$ Commented Apr 29, 2016 at 15:53
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    $\begingroup$ Its like "grampa's axe" story: It belonged to him and it keeps going strong. Had the head replaced twice and the handle replaced 4 times... :) $\endgroup$ Commented Apr 29, 2016 at 17:38
  • $\begingroup$ Your teleportation example seems to either be the novella "Think Like A Dinosaur" by James Patrick Kelly, en.wikipedia.org/wiki/Think_Like_a_Dinosaur or a marvelous example of parallel literary evolution. $\endgroup$ Commented Apr 29, 2016 at 17:43

There's another way to do it, and you stay you this way

#Keep calm and do it incrementally

Ah, but emotionally as a flesh-based mammal with no history of backups, syncs or restores, the concept that you are fundamentally just data makes you uneasy. Who cares that ghost-in-the-machine dualism was disproved centuries ago? We just did not evolve this way.

Think about it: you would never trust that impostor to be you. As the real you lays dying it a futuristic battlefield somewhere, it is in bed with your significant other, touching them, leering over them. All the while perhaps lacking internal subjective existence, a zombie with your memories. The horror.

Your savanna-trained flesh mind recoils in fear and disgust. That thing cannot possibly be you! No. We cannot have that. Two versions of me? At the same time. Impossibru. Div/0!!!!1 (or its flesh-brain equivalent)

The patient AI doctor sighs (we get these nut cases every day), and suggests a different approach.

Instead, we follow this path:

Step 1. Using a complicated machine, we replace just 1 neuron of your brain with a synthetic equivalent, copying its connections and ability to reshape, generate new and prune its existing dendrites as well as accept new connections from other living or synthetic neurons. This should be fine, after all we lose thousands of neurons (without replacement!) every day and never even notice.

Step 2. Take some time, maybe even a few days, if feeling particularly antsy. Once you are satisfied that you still have your own subjective experiences and all, and that you are still you, you replace a second neuron.

Step 85,999,999,999. Once you are satisfied that you are still you and still have your own subjective experiences and all, and that you are still you, you replace a the second to last neuron.

Step 86,000,000,000. Replace the last neuron.

Congratulations! You are now synthetic and the possibility of longer durability (since outright immortality is ruled out by the laws of our universe) is within your reach. You can now back up your self and reload states, store those or memories in nonperishable form.

No longer will you die like the creatures of flesh that are less then you are, no longer will worms and bugs feast on your flesh, but instead you may rise above them and become the master of your own destiny.

If you feel the urge to duplicate yourself now, you may, although for consciousnesses that begin in the flesh, there usually is a certain irrational reluctance and some minor issues & changes that need to be sorted/ironed out to enable a true sync process, such as tearing out your outdated dorsal spinocerebellar tract (you don't need it do you?) and replacing it with something more appropriate for controlling multiple avatars.

  • 1
    $\begingroup$ Slight problem with this approach - replacing one neuron a day is far too slow. To fit the incremental approach within a modern human lifespan, on average roughly three million neurons a day or so will need replacement. There's also going to be the semi-solipsistic fear that all the people who've gone through the operations successfully are merely programmed to say they're still conscious. Philosophical zombies are starting to look rather less hypothetical these days... $\endgroup$ Commented Apr 29, 2016 at 16:32
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    $\begingroup$ @StephenVoris Nobody said a neuron a day. I said take a few days after the first one, to get used to the idea. Take more breaks as needed. Once you get comfortable, we'll yank out millions in quick succession. I'll take durability over semi-solipsistic fears any day. $\endgroup$ Commented Apr 29, 2016 at 16:40

I think your question hinges on intuitions about physical and conscious continuity as necessary prerequisite for personal identity.

In Old Man's War consciousness is transferred to a new body by synchronising the new and the old brain. Imagine you are connected to a new body without any brain activity so far. At first you are only aware of your old body, then you are aware of both bodies and finally you are only aware of your new body (because your old one is euthanised). In this case the transition is experienced as continuous consciousness and you would be hard pressed to argue that "you" aren't "you".

Another idea championed by Ray Kurzweil among others is that you replace small parts of your brain with chips (possibly to counteract age inflicted damage), then these new technological brain cells learn to interact with your biological brain and ultimately your whole brain is only hardware and software. Here you even have a physical continuous identity because the single changes are so small. Also there is no "old you" around.

This kinds of technique could possibly assuage your misgivings about immortality.


This question kind of depends on if you allow for the existence of a soul (as either a spirit or a 4th dimensional part of us or whatever that can exist beyond the death of the body) or not.

If not, then all that we are is electrical signals in the brain, and a complex computer would be able to simulate it.

This is the idea behind the digital eschaton, where every possible brain configuration will be able to be simulated, and everyone that could have existed will exist in the simulation.

If we do have souls then the upload will be a copy, not really you, but the you that is the copy probably won't know the difference.

  • $\begingroup$ Unless your soul is tied to you mind and concept of self, more than the random collection of atoms that is your body. In that case, your soul might leave your body and remain with your uploaded mind. $\endgroup$ Commented Apr 29, 2016 at 3:54
  • $\begingroup$ @Xavon_Wrentaile That's a fair point. I wonder then if your soul would be duplicated then, or if the body would lose it's soul. $\endgroup$
    – AndyD273
    Commented Apr 29, 2016 at 13:05
  • $\begingroup$ False dichotomy here. Between a theologically immortal soul and a classical mechanical or electromechanical network lies quantum physics. We may have a fundamentally un-copyable identity well grounded in physical reality. $\endgroup$
    – nigel222
    Commented Apr 30, 2016 at 11:15

True, you are not immortal. I probably wouldn't bother uploading my brain. What difference does it make for me? But what about the world, and history? Because you wouldn't be immortal. But your self would be. Let's picture we uploaded... I don't know, Donald Trump's brain to a computer.

This computer (or robot if you need a human-like form for interaction, because we humans are so limited) would keep living. Since his mind is equal to a human's it could be argued that is a person a deserves a person treatment. The actual Donald Trump's human body will eventually degrade and die [citation needed] but the Robot Trump would continue existing. It would continue growing, maturing, as a human would given that lifespan

Take Jack Harkness, for example, every time his body rebuilds... is he the same? No! From a "first person point of view", he died. But he is considered immortal For "the world" there's no difference. Hell, even for the "new him" there's no difference, since he keeps his memories.

Eventually, after 300 years people would have forgotten about the long dead human Donald Trump [citation needed] but they would still know Robot Trump. For them, the original Trump would be just a phase of the Trump existence. First he was a human, then he was a robot (with a bit of an overlap but whatever, who cares?). So, to practical effects, the Trump persona would be immortal. It would be for the rest of the world.

For another example, imagine we go back in time and upload Julius Caesar's brain to a robot. And we leave him there. Wouldn't people say that Julius Caesar is immortal? Not the human, but the personality? What difference does it make for you?

Imagine the same with great artists like Picasso, Da Vinci or Van Gogh. They would continue growing and evolving. Sure, maybe they would become disconnected from humanity and their artwork could go worse... but wouldn't you be curious of what could they create in an infinite lifespan? What would they become?

For an inverse case, check Bicentennial Man and ask yourself this question. Do you consider the man at the end the same "person" that the robot at the beginning? (Related to the "Ship of Theseus" that @CortAmmon mentions in his awesome answer) Because if so, the principles still apply the other way around (even if with a bit of an overlap when the both exist).


For all intents and purposes, the robot is you - or at least you were the same person at the time of your last synchronisation.

Your uploaded brain, being purely data, can be copied and synchronised countless times. As the robotic versions of you live their lives and synchronise with each other, they will share memories and grow in ways that you would, where you is the product of your experiences, personality, memories and choices.

Yes, one of you can be destroyed but you (collective) only loose those experiences that have not been synchronised. You are immortal because as long as one of 'you' still exists, the sum of your experiences exist, independent of any singular stream of consciousness.


When someone say they are going to transfer there brain into a new body they usually don't mean just there brain but instead they mean that they intend to transfer their consciousness to the "fake" body. The idea is that this would be more then just there memories or even their personality but something more. There entire consciousness, this a little hard to explain so to keep things simple people just say that there going to transfer there brain.

So to make it simple when says brain upload, they real mean consciousness upload.


You should research the Turing Test

The basic idea of the Turing Test is the ability to create a computer that you cannot distinguish from a human. So, maybe it's possible to put a "human" into a computer in some way. And if that were a copy of a person, then based on the idea of the Turing Test, that new "person" would be indistinguishable from the person that was copied...

The basic idea is this - while you can argue about soul, spirit or even the concept of consciousness, consider this:

Are "you" defined by the cells that make up you body? Most of your cells die over time, and by some estimates you have "all new cells" over a 3-5 year period. So, 5 years from now ... are "you" still "you" if all your cells are different?

Brain cells and bones are the exception. So... it seems "reasonable" that if what your brain contains defines "you" because everything else died and was reborn, then an "upload" of that information would basically be a copy of "you". The rest (besides the bones) define another aspect of your existence, but not "soul" or "spirit" or whatever you might define as "you".

However, your behavior is also defined by the body you occupy. If you occupied a robot body, you will experience life in a different way - and a flesh version of you and a robot version of you, even if they start the same - would likely be dramatically different over time. Even two robot versions of you would have different experiences, leading to different thoughts, lessons, conclusions and even beliefs. Different souls???

Anyway, the idea that "you" are defined by your thoughts and ideas is much more compelling than including the body, which is really just the system that supports keeping the brain alive (and propagation of our species...).


Here is what I will call the "Jim Test" (based on the Turing Test, but somewhat of the reverse):

Assume I fall asleep and my brain is copied into a clone body of mine. Then keep my original body asleep artificially (drugged or whatever). When my clone body woke possessing all my memories and having just fallen asleep, would it know anything happened at all? Would anyone else be able to determine that anything happened? (Besides those performing the "operation" or experiment or whatever; and remove all ability to put chemicals or markers on the "new" body. And probably ignore that the new body may be exceptionally hungry or weirdly disoriented from the procedure.)

That's the idea behind problems like creating a "clone" - if in every way I appear to look and act the same, but I am really a "copy".. how would anyone know but me? In fact, would I know? So if the above experiment worked, I could move my brain into a younger clone of me. Then "kill" the old body and go about my business. Then continue to grow younger clones of myself, make "backups" of my brain every night and every few decades (or whenever it might be convenient) I upload to the new body and destroy the old one. If I can't tell the difference, what do I care?

In fact, if the next clone I make include carbon-fiber reinforced bones, I might not notice much of a change, but I would probably benefit from that. And the next time maybe throw in plastic lenses for eyes to correct my vision? You get the point - eventually I could go through a series of transfers where I'm essentially "me" but a robot me... and now what? I'm clearly not "me" but in some way clearly I still am me.

However, such a thing seemingly violates the concept of a "soul" or "spirit" ... an immeasurable attribute of identity and self that is intertwined with both my body and mind, to make a complete "me". Some would take that as proof such a thing does not exist.

  • $\begingroup$ Do I understand your point correctly: as long as people cannot distinguish a human and his robot clone by talking to them, these two can be considered the same person? $\endgroup$
    – user8808
    Commented Apr 29, 2016 at 14:31
  • $\begingroup$ I edited my response to try to clarify. I think you are essentially following the logic. Does my edit help? $\endgroup$
    – Jim
    Commented Apr 29, 2016 at 14:47

In your example, the "immortality" lies in the perception of other people.

Assuming the technology yields a perfect replica of your brain and everything to do with it, to your family and friends it's you that is in that computer or robot.

You have an influence on your environment:

  • When you die, your loved ones go through the grieving process.
  • When you interact with them, they have learned behaviour around you. You affect their decisions, their life, and even their personality.
  • Your significant other has brain chemicals flowing dependent on your presence.
  • You likely have a job, or some career, that produces work for society.
  • If you have children, you're raising them and leading them to be a member of society.

So when they have access to this entity that is a copy of you, all of those details are carried over, with the differences that may arise from the different body.

Your significant other's brain doesn't go through withdrawal from your absence. Your family still benefits from your presence. Your consciousness can still produce work, especially with a body to go with it. So your business/career continues without the biological copy, too.

So to the rest of the world, they have a copy of you that's not subject to things like cancer. They have access to something they can likely continue to copy as well.

So the immortality is more like the abstract immortality we attribute to things like legacy.


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