How much could we replace of us before we're no longer ourselves?

[Deleted]

Artificial limbs, more and more advanced. Stuff like implants, nanites etc, being developed as we speak. It's quite interesting, being able to repair an injury faster, to perform as good or better than healthy humans even after terrible accidents etc., isn't it?
Yet it also raises a question, how much could we replace of us before we're no longer ourselves? I'm not talking as a race, or as culture, I'm talking about what makes you be you.

Some people think the heart of a person is where their soul is. On the other hand there was a person who had his heart removed and replaced by a machine. He didn't live long enough after to see how that truly affected him though.
What about the spine? It transmits all the info from the nerves to the brain, from the brain to the muscles, would we not be us if a machine did that? would we be different?
And last, but not least, our brain. Where all our decisions are made, where all our information is stored. Replacing any part with a machine or nanites might seem like suicide yet... people get brain tumors, they get accidents, they get parts of their brain removed due to this. While many can't adapt, some can by using other parts of their brain.

So how much of us could we replace before we're no longer us? In the end, could we replace every organical part if we transferred the info to a robotical one, like a hard drive? I don't think so, while the copy might still think it's the same person, the original would still be dead. Of course, if the original was not tied to any organical part but rather it was tied to energy or a soul, that could theoretically be transferred to a new body, could it not? But if said soul does not exist, how much of the organical you could be replaced before the true you ceases to exist? If parts of the brain would be replaced piece by piece, would you even realize it?

Now that is the question. What do you think?

[Medusa Cascade]

Everything but the brain

[hulkgor]

You will always remain yourself as long as you keep your brain, i'd say.

No matter how many organs or limbs you replace, you'd still be you, even if a bit traumatized or shocked by whatever situations led to it.

[Realsykes]

http://boards.straightdope.com/sdmb/...d.php?t=310743

^ Read that.

Poses solid questions, and maybe you'll find answers.

[Sanguiris]

As long as you still have your brain youre still yourself imo, the rest are just hardwares

[Kronik85]

If we are defining the soul as the thing that gives your individual identity then you can replace everything providing the end result is still "you". If the net result is that you start saying "kill all humans" then obviously this needs revision but for the time being I don't see why you can't replace everything.

[Polybius]

Here's a good article on that:

http://www.utne.com/mind-and-body/ship-of-theseus-identity-ze0z1311zjhar.aspx

[May90]

Let's take an analogy. Suppose you have a house. Over ages, the house is constantly repaired, revamped, modified in multiple ways - but it still remains a house. At some point, the house becomes so old, it is time to destroy it. It is at that point that it is no longer a house.

So, until we die, we are ourselves. Whether we die when everything in our body is replaced or not is the real question.

[Independent voter]

If they can digitize your thoughts and upload them, so you're floating around in the digital cloud as an artificial intelligence, all your memories hopes and desires intact, aren't you still you? If you are you, then you're still human.

[Egregious]

Literally everything except your memories and all the information you have accumulated over the course of your life (in other words, memories).

[crazymack]

Any change at all would change one self, the signal developed because of the system it is propagating through. But another bit of information you need to consider is the amount of "change" as well as propagation delays for individual signals.

Everyday I am dying only to be born a different person.

[Nurvus]

Everything but the brain

What if we develop nanites that are capable of repairing and replacing brain tissue?
How much of the brain, then?

[Deleted]

If they can digitize your thoughts and upload them, so you're floating around in the digital cloud as an artificial intelligence, all your memories hopes and desires intact, aren't you still you? If you are you, then you're still human.

Ah, but here's the deal. Let's say I make a movie on my camera. I then copy it on my computer and then on a cd. It's exactly the same movie, isn't it? Well... no. If I delete what's on the camera, even if I have a copy on the computer and one on a cd, I'd still have destroyed the original.
Same for the human. Even if you copy everything, the desires, wishes, memories etc but in the process the original is destroyed... aren't you dead?
This reminded me, this was the plot in Star Trek regarding the teleporters. Some people would say that a teleporter simply destroyed the original and created a copy at a location. Everyone said this is dumb. Yet in one episode there is a storm on a planet and when Riker wants to get teleported... he can't be, yet the ship leaves. Years later he founds out that due to that storm the teleporter created a Riker on the Enterprise yet the original didn't disappear... so thus confirming the fact that the teleporter actually destroys the original and creates a copy, meaning that every single time anyone used a teleporter in Star Trek, they died. Of course, the copy wouldn't know that, they'd look the same and have same memories etc as the original. But if you were the original, you'd still be dead.

[Primalthirst]

I think a lot of people are discounting the body. Our brain might hold our memory and consciousness, but it doesn't know how to relate to existence outside of the confines of the human body. Literally no-one has any idea what putting your brain in a monster truck or a hard-drive or in a glass jar would do to your consciousness, there's a fair chance you'd go into shock and insanity.

[Space Troll]

What if we develop nanites that are capable of repairing and replacing brain tissue?
How much of the brain, then?

that's an augmentation, not full replacement.

[Deleted]

Everything except my brain and dick.

Good point. Being still able to biologically reproduce is rather important when you think of it.

- - - Updated - - -

I think a lot of people are discounting the body. Our brain might hold our memory and consciousness, but it doesn't know how to relate to existence outside of the confines of the human body. Literally no-one has any idea what putting your brain in a monster truck or a hard-drive or in a glass jar would do to your consciousness, there's a fair chance you'd go into shock and insanity.

Obviously the artifical body should provide the brain with similar stimulation as the biological one. Just putting human brain in a jar or a machine and keeping it alive, but without the ability to perform any natural human functions and activity, would certainly drive the brain crazy. No, it should be an android-like humanoid body that obeys the conscious commands of the brain just like your normal body does, and also gives feedback just like our nervous system does.

[Deleted]

Replacing your biological body sure has effects on your personality and perception of the self. As you become less human you probably also feel less human and you would feel less like yourself. Imagine looking at yourself in a mirror and all you see are prosthetic parts, a foreign element that you now call yourself even though you know it's not really you. It's like waking up one day in an entirely different body than you were born in. That would fuck you up in the long run, I'm sure of it.

And if we're talking cognitive enhancements then it becomes even worse. Your personality comes from how you interpret events in the past. Those interpretations aren't really accurate and they are definitely biased; It's your brains version of reality and that has shaped you into the person you are today. If you have a perfect memory there's no telling what that would do to your personality. There would be no room for personal interpretation, you'd have perfect and factual memory of every event in your life, it would just become stored information.

So yeah, I don't believe it would require a lot to destroy our current personalities.

[Atrea]

0%.

Ask anyone who has lost a limb if they are the same person as before. The person you are is never some permanent, immutable thing; it is comprised of our life's experiences. Losing your arm would change who you are, just like losing your job would.

[Deleted]

Everything but the brain

This. Unless we manage to actually transfer our conscience aswell without just making a copy and deleting the original.

[Primalthirst]

0%.

Ask anyone who has lost a limb if they are the same person as before. The person you are is never some permanent, immutable thing; it is comprised of our life's experiences. Losing your arm would change who you are, just like losing your job would.

I agree that every little piece would affect you. But how much of the change that amputees etc experience is due to them no longer having a functioning limb and how much is due to it being prosthetic. I'd wager if the artificial limb performed identically to the original and didn't have issues with rubbing etc on the wound site then the change in a person's outlook would be less severe. I can't speak with authority on the issue, but I feel like no longer having a usable limb (due to limitations of modern science), rather than what the limb is made of is the more critical factor.