On 12 Nov 2012, at 19:41, John Clark wrote:

On Mon, Nov 12, 2012  Bruno Marchal <marc...@ulb.ac.be> wrote:

>> I have no idea what " its personal memory of the past in the future" means

> It is the content of the diary that the candidate brings with him in the teleportation box, and in which he will put the result of his self-localization after having push on the button

According to your protocol the Helsinki Man is destroyed

Precisely: after having been scanned, at the correct level (which exists by the comp assumption), the body is destroyed. The expression "the Helsinki man is destroyed" is ambiguous in the comp frame, as "helsinki man" can both denotes the body, or the person, which of course is not destroyed in the comp theory, given that the helsinki man survive in M and in W.

when he pushes that button so he writes nothing at all in his diary after that.

"he" is ambiguous. If you mean the body, I am OK. If you mean the person, I am not OK, as, by definition of comp, the person survives.

As for what the Helsinki Man imagines will happen to him after he pushes that button I really don't care because that depends entirely on the particular personal beliefs of the man involved.

That is non sense.

I'm not interested in what the Helsinki man believes will happen to him

But it is part of the reasoning to address that question. The fact that you find a line in a reasoning interesting or not interesting has nothing to say on the validity of the reasoning.

I'm interested in what will really happen to him and to find that out the Helsinki man is of no use because he no longer exists in the future.

By comp, it exists in the same sense than you exist after a successful clinical operation.

To find out what happened to him we need to rely on memory not prediction and we need to interview all the parties that still exist, and that means the Washington and the Moscow man.

I agree 100% with this. But keep in mind that the question is a prediction, and the memories of what they have lived will be used as confirmation or refutation of the prediction done in Helsinki.

If we do that we find that the Washington man remembers being the Helsinki man and remembers that man walking into the booth and being instantly teleported to Washington where he is alive and well,

OK. He feels alive and well, and he has kept his identity. he is the Helsinki man. So he can verify if his prediction done in Helsinki is correct. If he predicted "Washington", that is correct, for him. If he predicted "Moscow", that is incorrect for him, and if he predicted "Washington and Moscow", that is incorrect for him (and for the other). If he predicted "washington OR Moscow" that is correct for him, and for the other.

and we find that the Moscow man remembers being the Helsinki man and remembers that man walking into the booth and being instantly teleported to Moscow where he is alive and well.

Same remark. You are correct in both case, but fail to verify the prediction which was asked to him in Helsinki.

>> or who "its" refers to

> Up to the duplication, it concerns the Helsinki person, and after the duplication, it concerns all the copies. As the diary has been duplicated too in the two places, it will contain W, or it will contain M, from all possible subject being interrogated.

And if John Clark had been the Helsinki man you would find that his diary contained a correct prediction of what was going to happen as can be easily verified by asking everybody that still existed. If Bruno Marchal had been the Helsinki man you would find that his diary contained a lot of mystical stuff that can only be verified by asking the Helsinki man to remember the future.

I have no clue what you mean by "remembering" the future, nor to what mystical stuff you allude too. On the contrary, you can replace the humans by simple proving machine having simple means to localize themselves, and simple means to do simple inductive inference. This comes from the fact that all notions involved, including the notion of first person, in this setting, admits transparent third person description, like the diary, the bodies, etc.

In general the only way to know if a mind has survived from point A to point B on a timeline is to look back from point C, there is no way to know for sure from point A because predicting is hard, especially the future :>), and because we remember the past and not the future.

OK, but nowhere anyone is ask to try to remember the future. You (in Helsinki) are just asked to predict a future outcome of a well defined experience: localizing oneself in a city.

>> but I can predict that in the future there will be 2 people who call themselves John Clark

> That's correct.
>> and BOTH of them will remember being me, the Helsinki man of right now.

> That's correct.
>> I can also predict that one of those people will feel like he's in Washington and only Washington and the other will feel like he's in Moscow and only Moscow.

> That's correct.

Thank you.

> And from this it follows that one will write W in the diary, and the other will write M.


> Both will agree that they were unable to predict this individual particular outcome.

WHAT?!! Both will agree that was exactly precisely what the Helsinki man predicted would happen,

No, as you predicted W and M. But "W and M" never occurs. It is always refuted by all copies. You are still confusing "the guy in in this city" and "I feel now to be in this city", that is you forget that the question concerns the future first person experience, as described by the result of self- localization in a city written in the diary after reconstitution and self-localization.

even if the Helsinki man was Bruno Marchal, even he made the correct prediction. Bruno Marchal predicted that 2 people will feel to be the Helsinki man and Bruno Marchal predicted that nobody will be experiencing Helsinki anymore because the body there has been destroyed, and Bruno Marchal predicted that both people who feel like the Helsinki man will be experiencing one and only one city

Yes. And the question was "which one?". And as you say, after poushing the button, he knew that it is only one city, and not both, so "W & M" is refuted.

and Bruno Marchal predicted that the Washington man will be the one experiencing Washington and the Moscow man will be the one experiencing Moscow. I just don't see what more is needed for a successful prediction.

Again correct, but trivial, and evading the question asked.

>> So Bruno, what part of my prediction do you think I got wrong?
> You said "W and M". here you were correct on all point,

Thank you.

> but did not give the answer to the question asked to the Helsinki person: "where you will feel to be after pushing the button",

I did not answer the question for 2 reasons:

1) It's a incomplete question because with that machine and all its duplication and destruction it is not clear who "you" is; it's the same reason I don't answer the question "how long is a piece of string?".

You are all the guys involved. By comp, the M-man and the W-man are the H-man. But the H-man knows in advance that, from its first person perspective, after pushing the button, despite being the two man, he will feel being only one of the two men, as he has differentiated from the copy. There is no identity problem, other than the usual one. We might use that tought experience to put light on the identity question, but that would be a different topics. The reason is that: wheoever you will feel to be, you will feel to be a unique person in a unique city, and the question was about evaluating, before oushing the button, the chance of being the W or the M man, after pushing the button.

2) The question demands a single answer but in this case there is not one.

This contradicts what you said above, that the guy knows in advance, that whoever he will feel to be, he will feel to be in a unique city. So there is a single answer "W or M, but I can't be sure of which one". There is nothing mysterious, as it is equivalent, phenomenologically, with a perfect coin throwing. Of course the reason of the indeterminacy is different. With a coin throwing the indeterminacy is brought by the complexity of the coin motion, but here the indeterminacy comes from the numerical identity of the two reconstituted body in two different environment.

I won't answer the question "what is the one and only number that solves the equation X^2 =4 ?" either because the answer is 2 AND -2, there is no one and only one answer.

But there is only one outcome for the WM- experience. It is either W or M, as "W" means "I feel in W", and "M" means "I feel in M", and that you know in advance that you will feel, whoever you might be, to be in only once city. You argument is either criticizing the notion of probability, or is again a confusion between a 3p description of the issue, with the 1p description asked.

> or "what do you expect to write in the diary after pushing the button and proceed to the self-localization?"

It doesn't matter what the Helsinki man expects to happen it only matters what will happen,

This is eliminativism, and besides, a simple refusal to handle the question asked.

Somehow I am happy you make this points, as you are in trouble. Your posts show that you do understand the difference between the 1-views, and the 3-views, as you notice that the 1-views, after the experience is completed, are unique (feeling to be in only one city). So to object on the indeterminacy, you need to pretend that the question does not make sense. But the reason you give consists in either contradicting that 1-3 difference, or in eliminating the sense of the assertion made by the reconstituted person "I feel to be in one city", which is a from of (opportunist) elimination.

and to determine that we need to examine memory not predictions, and in this the Helsinki man is of no use to us because he can't remember the future.

But he can predict it. With that protocol the prediction is P(Vienna) = 0, P(Brussels) = 0, P(Moscow) = 1/2; P(Washington) = 1/2, P(Sidney) = 0, P(beijing) = 0, etc.

> from their 1p view, in only one city,


> and the question was "which one?".

If you're the Washington man then the city you'll see is Washington and if you're the Moscow man then the city you'll see is Moscow; and you become the Washington man by seeing Washington and you become the Moscow man by seeing Moscow. I know this sounds trite but you asked the question not me, and tautologies do have one virtue, they're true.

The question is asked to the Helsinki man, before the experience is done. The helsinki man does survive, by definition of comp, in both Moscow and Washington.

So we can interview the Helsinki man in Moscow, and the Helsinki man in Washington. Both can understand that the prediction "W and M" is refuted, but that the predictions "W or M" is confirmed.

> With comp the helsinki man survives the double teleportation, despite his body has been annihilated,

I agree with that,


but if there was a delay and the destruction of the body in Helsinki had not happened immediately after the copying then the Helsinki man would not survive because then he would have had time for a last thought. How long is immediately? About a second or two.

In step three we suppose such delay null. You are answering step 4, here. Nice.

> and so I can interview the Helsinki man in both M and W places, and both assess to be now in one precise and particular city.

Exactly precisely the outcome that John Clark predicted.

So it makes sense, in case we were redoing the experience to ask for an evaluation of the chance of living one among the two exclusive first personal outcomes. You have just to interview each copies, and remember that the question was about that exclusive experience, and not about a 3p description of all the possible exclusive experiences.



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