Hacker News Reader

Comment by danieltillett | Hacker News Reader

Isn't this the same as saying you are a different person every morning and that the person that went to sleep and the person that woke up are separate people?

View on HN

No, its very probably not the same. The brain doesn't shut off when you go to sleep. It keeps going, it keeps doing it's stuff, messing with memories, thoughts, all the bodily functions and a whole extra stuff that we don't know too well, but which probably still makes you you. Killing that brain and then simulating it somewhere else is not the same.

More importantly, does anyone suggest that running the original brain and the copy doesn't result in two separate diverged intellects? If running two results in separate consciousnesses then obviously they are not the same.

I don't think that follows. If "your" consciousness is just the consciousness that has a continuity of memory with a previous version of you, then the two copies would both be you, but they would not be one another.

Let's say that I a suitably advanced fMRI is developed that is able to map out the connectome non-destructively, I use this device on you to create a copy of your mental state, and then let you go about your day. At some point later I turn on a whole-brain simulation from this data. What do you, the you-that-walked-into-the-scanner expect to experience?

You'd experience nothing unusual.

I agree. But the further implication is that for the same reasons, if your brain is plasticised and later scanned and turned into an uploaded whole-brain emulation, you'd still be dead. Uploading is not a pathway to personal longevity, or whatever you want to call continuation-of-me-not-just-my-memories.

That's the crux of it all, isn't it? Is your self any more than your personality and memories? If so, then you'll have to resort to a soul or some such. If not, then the upload is really 'you', or a copy anyway.

And who's to say a soul wouldn't attach to a copy anyway? Souls are not that well understood. Perhaps it would be fooled by the copy, or have an affinity for it, or some such. As long as we're speculating.

No, there are plenty of perfectly reasonable physical theories for the nature of consciousness that don't equate identity with memories and don't involve souls. There's no reason to resort to dualism.

For example, there is the identity-is-the-instance-of-computation theory which says that it is not the information being computed (memories) that is relevant, but the computation itself.

Agreed, the hardware/wetware is just as important as the bits being uploaded. Especially for chemical brains that store much of personality as neural wiring.

But lets say that's uploaded as well, as part of the 'program' details. Then where are we? An 'instance' of this is not actionably different from any other, if it behaves exactly the same. Its arguable that they are the 'same person' in some sense.

It matters to the person who is now dead and not living on in the machine.

But they are living on! Kind of. Like you are, in that body of yours, once all the cells are replaced by new cells every decade or so. Its ok; you still sound like the same person.

Another strawman. No one is claiming that identity is tied to the molecules that make up the body, even in aggregate. There's a sense in which a car remains the same car even after continuing comprehensive maintenance has replaced every single part, but that car stays different from the next car off the production line. Does that example make sense?

Come on! If its a new car, its a different car. Doesn't matter how convoluted the path to get there (replace every part or build new). Not a strawman; an example pointed right at the argument that 'a copy isn't the same thing'. Be fair.

You be fair too. The instance-of-computation model of personal identity allows for cells of your brain to come and go, but as long as the whole thing is operating continuously, you remain. It is exactly analogous to my car example.

Its also exactly analogous to my build-an-entirely-new-one and program it exactly as the previous one was programmed. It has exactly the same result. If I did it without anyone looking, they would never be able to tell the difference.

Except the original that you replaced with your copy. You're opting for an external functional description of identity but the discussion is about the individual.

It should be understand as conceded that a perfect copy of me would pass any Turing-style test applied by an external auditor that the copy is me, but that doesn't mean that I am the copy.

Its different in a sense, sure. But consider: if I replaced it so perfectly that it was atom-by-atom identical, then God himself would not be able to say if it was you or not. Unless we admit to some external agency that defines 'you' that is not present in the mechanism e.g. a soul.

That's obvious to me, but I've learned that it's not obvious to everybody. It's an instance of the mind projection fallacy that your or I think that is a simple obvious truth but others think the opposite is just as intuitive. I sometimes wonder if different people have different experiences of consciousness and self-identity...

What about what happens during hypothermia? Both during Cardiopulmonary bypass and cold water immersion, the brain is cooled enough that activity stops.

I personaly subscribe to that opinion. Even if the change is negligible. This is why I would like to be sober and conscious in case of any uploading.

Reply on news.ycombinator.com