Comment by EGreg | Hacker News Reader

Comment by EGreg | Hacker News Reader

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This is all basic stuff. Think deeper.

You go to sleep every night. When you wake up the next day, how do you know you're the same person as yesterday? What does that mean?

Now consider if you didn't have memories of the past. What would make you "you"? The body would be the same but your amnesia would change things, eh?

Now what if you knew next week you would lose your memories for sure, but this week you can go on an amazing vacation. Does it matter where you go? It matters to your current self but to your future self.

Now think about sacrificing pleasure now so you can live a longer life. Or feel good about your life at 80.

Now think about the afterlife. What if you are reincarnated with no memories of the past? We already kind of established that "reincarnated you" wouldn't care about current you. But will current you care about reincarnated you?

Consider this: if a "future you" doesn't remember being "current you" how are they really different than a random person with a similar body who also has amnesia?

In short, long term, is it all about the memories?

What is the self preservation instinct about?

Finally the big one... if there were no conscious observers at all, in what sense would anything exist? That is, if I described to you a universe that you can never detect or deduce must exist from any observations in this one, how would saying "that universe EXISTS be different than saying it DOESN'T EXIST? It seems the word itself requires concious observers. Thus, the concept of consciousness and existence may be two sides of the same amazing conundrum.

Your comment made me recall this classic comic: http://existentialcomics.com/comic/1

I personally try to resolve this quandary in my head by defining my consciousness not as a single state at an instant in time, but rather a pattern over a time continuity - just as mass and matter occupies a continuum of space instead of a single point.

Going even deeper, from one moment to another - how do you know that you're you? After all, you're not _exactly_ the same, since each moment brings new experiences, ever so slightly changing your memories. Quantum entanglement, perhaps? If not, aren't we a collection of particles with a certain probability distribution that we're able to influence ourselves?

(Maybe this whole discussion is less interesting to Buddhists trained in not-self thinking. :)

The classic question, if a tree falls in a forest and no one is around to hear it, do the air molecules still vibrate?

wait - didnt you just break the question? It's not about molecules vibrating, it's about whether the concept of "sound" has meaning without a hear-er

It's just a throwaway snide remark about expecting metaphysics to have concrete answers for anything (It's not even coherent; if the air molecules don't vibrate without an observer, there probably isn't a tree or a forest either).

(metaphysics is still an interesting and useful exercise, but the state of not having an answer to a particular question isn't much more of a real conundrum than not having asked the question in the first place. I mean, when you are hungry, eating feels pretty good regardless of whether the food exists or not.)

You know you're the same person as yesterday because without you, there is no knowing. A clone is no more you than an identical twin is you. What makes you you is the ability to ask the question in the first place. If you were dead, there would be no question.

I don't follow.

You know based on your ability to ask the question that you currently are you and not a clone of yourself, but you don't know that the person yesterday was you and not some other person that you were cloned from.

but you don't know that the person yesterday was you and not some other person that you were cloned from.

The parent did not say anything about this and neither did I. Of course you cannot know whether you are a clone or not. My point is that if a clone is made of you and you are killed, you will be dead, you won't be the clone.

You both did.

> When you wake up the next day, how do you know you're the same person as yesterday?

> You know you're the same person as yesterday

Why is there no knowing without a you? Won't the clone know just as well as you that he's you?

What defines "you"? The matter you're made of?

Is it a particular arrangement of that matter? (Would you care if your neurons were replaced one by one, while keeping the same arrangement?)

Is it your memories, your thoughts, your inclinations?

Or is it something else?

Because when I die (or anybody else dies), the universe ends for me (or them). The clone is just a different person who can't tell that he's not me. But he is him.

The only thing you can really know for sure is that you're still alive. When you're dead, you know longer have the ability to know.

I guess my question is, yes, you can know that you're still alive, but how can you know that you're still _you_?

What a weird question. You're always you, until you die. Even if you became totally paralyzed, blind, deaf, etc. (total sensory deprivation) you'd still be you. All that is you is just the voice in your head, the ability to ask the question, and to think about an answer.

As for what happens to your body or anything else in the world? You can't ever get rid of those doubts. The only thing you can know without a doubt is that a doubter exists. Cogito ergo sum, as Descartes wrote.

In context of the thought experiment there can be more than one person with equal claim to be the person that you believe yourself to be. For example, given the postulated copying technology there could be Two or ten or a hundred people with the same claim 91 you to be today's version of who you remember yourself to be. The only thing that makes one person's claim better than another's is a perceived continuity of physical substrate. But even that perceived continuity is at least partly a fiction, since the physical substrate isn't really the Same from one day to the next, or even from one moment to the next. Bits of it are always being swapped out, lost and replaced. It's a valid question to ask, in that context how do you know when you wake up that you're the same person who went to sleep? Why do you think you are the same person, as opposed to an entirely new person who happens to have inherited a particular batch of ingredients of memory for assembling a story about who you are?

My argument is that you don't really know other people, you only know yourself. Clones don't even have to be physical replicas of people, they need only be entities or systems which can pass the Turing test. The fact that a clone may think it is me makes zero difference to my friends who have no way of knowing and it makes zero difference to me because I can clearly see that it is a separate person from me.

Now, you could contrive a thought experiment where you clone me in such a way that neither I nor the clone know which one of us is the clone, but then, how is that any different in principle from babies switched at birth in a hospital?

Your memories don't define you, since they may be false. The only thing that defines you is your consciousness in the present. Everything else is I/O, and subject to interpretation and trust.

My point is that you don"t know yourself, either. You know in any given moment whatever self you have constructed from the sensations, emotions, inferences, and memories available to you. It "s conventional to assume that there is continuity with the selves that you remember, and that"s the default common sense position to take--a sort of pragmatic shorthand--but we don"t actually know that the continuity is real.

In fact, we do know that human memory is spectacularly unreliable, and, moreover, that it is a virtuoso liar, very accomplished at convincing us that we vividly remember things that never actually happened. It's proficient at rearranging memories and sensory impressions into ad hoc stories that we uncritically accept as true records of events.

From this point of view it seems a little over optimistic to me to say that we know ourselves, or to say that I know that the me of today is "the same person" (whatever I might mean by that) as the me of yesterday or last week or 1965.

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