On 28 Jun 2012, at 18:16, John Clark wrote:

On Wed, Jun 27, 2012  Bruno Marchal <marc...@ulb.ac.be> wrote:

> comp allows self-duplication. That is the key point.


>> If you really had complete information then you could make 2 predictions: 1) I Bruno Marchal will write in my diary "I Bruno Marchal am now in Washington and only Washington" .2) I Bruno Marchal will write in my diary "I Bruno Marchal am now in Moscow and only Moscow".

> That's better. But still ignore the first/third person distinction.

I don't know what you're talking about. John K Clark, a third party outside observer who also has complete information about the proceedings, makes the exact same predictions that Bruno Marchal, the first person, does about what he will write in his diary. And events will prove that both are correct.

>> Both predictions will turn out to be 100% correct;

> Not from the first person point of view,

I don't know what you're talking about. The first person or second person or third person or the 99'th person can all be shown the entries from both diaries proving that the predictions made by Bruno Marchal and John K Clark were indeed 100% correct about what Bruno Marchal will write.

You said yourself that the first person cannot be defined. How could we verify that prediction? Except by feeling to be one of the W and M reconstituted person. And from their points of viex, the prediction of being in both place is simply refuted.

> the question was bearing on "I", not BrunoMarchal, which refers to a third person description. [...] You don't need to define it [I] to get the point that the proba on the localisation on the future sense of self is 1/2.

So you can't define "I" or even give a example of "I" that remains true for more than a second,

Actually I can define enough good approximation of it, and have done that in two ways (with the personal diary/memory content in UDA, and with Theaetetus' trick in AUDA).

and you believe as I do that you are free to add subtract multiply and divide "I" by any arbitrary integer; and yet you still think assigning a probability to such a vague constantly shifting uncountable specter means something so concrete you can give it a probability that means something. I don't.

But if you use comp you can predict that about all 2^n resulting persons in an iterated self-duplication will agree with me.

You say the probability of something to do with the non-defined ephemeral thing called "I" is 1/2,

There is nothing less ephemeral than "I". You ignore an important data in the discussion: our continuous experience of identity. The duplication experience does not change it, and that is a simple consequence of comp. Like in Everett, the observer does not feel the split.

but to me the meaning would be just as great (or as little) if you had assigned a negative probability to it of -1/2, or a imaginary probability of 1/2i; I have no idea what to do with any of these probability figures including yours of 1/2, I don't see how I could make use of any of them in any way.

Just look at the step 4, 5, 6, 7, 8, and then AUDA, and you can understand that the indeterminacy is absolutely fundamental. It explains the existence of the realm where the physical laws comes from.

> You ignore again the 1-3 distinction that I made precise.

I don't know what you're talking about. You admit you can't define "I" and so although both the Washington and Moscow man use the word "I" without hesitation when referring to themselves you can't know if one or both or neither really deserves to have that title,

They deserve that title because we have already agree that "I survive" in a successful teleportation. I just cannot be sure where I will feel if there is a duplication.

and yet you still assign a probability of 1/2 to something that is supposed to have something to do with "I", although it's unclear exactly what.

If you are willing to believe that the two copies have survived, we don't need a definition of "I", other than what we attribute to others when we say "he is conscious". In fact "I" is conceptually hard to define, but very easy to grasp. It has this in common with consciousness.

That sure does not sound very precise to me!

You invoke an unecessary, for the reasoning, notion of "I". The point is simply that you cannot predict in advance where you will feel to be after the duplication experience. The duplication thought experience has been invented for bypassing the personal identity problem. You have a machine with some button, and you are asked to make a prediction on the immediate personal outcome of a simple experiment. In step seven, you are just throwing a pen, and ask to predict what you will be be observing, in case a UD is run in the universe. I have no clue of what you don't understand, except that you sill confuse 1 and 3 views.



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