On Mon, Jul 9, 2018 at 12:23 PM, John Clark wrote:
> On Mon, Jul 9, 2018 at 7:03 AM, Bruno Marchal wrote:
>
> That would be true if the man were like you and didn't understand what the
> words "YOU WILL BE DUPLICATED" mean.
>
>
>>> >>
>>> Bruno, you're always talking about definitions but this is one of those
>>> rare occasions where one is desperately needed, so if you want me to answer
>>> that question you must first give me a PRECISE definition of exactly what
>>> you mean by "the Helsinki man".
>>
>>
>> >**
>> *It is guy who will survive in both Moscow and Washington,*
>>
>
> If that's what "the guy" means then obviously "the guy" will see 2
> cities. And before you start with the from the peepee not the poopoo stuff
> remember it was you who said "the guy" means "the guy who will survive in
> both Moscow and Washington", if that definition is too simple then give me
> a better one. I don't have a fetish about definitions as you do but in this
> case I have a precise unambiguous logically self consistent definition of
> "The Helsinki Man". Do you?
>
> >
>>> and before I can say we agree about the H-guy I need to know exactly
>>> precisely what you mean by "the H-guy”.
>>>
>>>
>>
>> *>The guy before the duplication.*
>>
>
>
> OK, now with this new definition of yours about what "the H-guy" means
> "the H-guy" will never see any city **after** the duplication or see
> anything else for that matter because the defining characteristic of "the
> H-guy" that you just mentioned is existing **before** the duplication.
> Try again, maybe the third time is the charm. As for me I think a more
> useful definition is "the H-guy is anybody who remembers being in Helsinki
> before the duplication".
>
>
Perhaps this will be precise enough for you:
Referring to Informal definition 3.2, it is clear that every guinea pig
state X has many (possible) successor states Y , arguably infinitely many.
As a colorful example, think about Abby the guinea pig’s state when she is
sitting in a caf´e, drinking water and thinking about the weather. One
possible successor state describes her experience while still sitting in
the caf´e a moment later, still drinking water, and asking herself whether
she has enough winter coat for the predicted cold snap next week. Another
possible successor state describes Abby, terribly frightened because
another guinea pig with a face mask storms the caf´e, shouting and
performing a robbery.
So far, Informal definition 3.2 seems completely unproblematic — it does
not seem to lead to any conclusions that differ significantly from any
layman’s perspective in everyday life. It can even be very practical for
the advanced civilization of guinea pigs. Suppose that the guinea pigs
have decided to take the hypothesis seriously that it is the information
content of successor states that determines the firstperson perspective,
not the material body itself. Then the guinea pigs may decide to build
teleporters.
Here, a teleporter is understood as a hypothetical device that is currently
beyond our technological abilities, but that does not contradict known
physical laws. We can imagine a teleporter as consisting of two devices, a
“scanner”, and a “replicator”. Suppose Abby the guinea pig wants to travel
long distance, say from Earth to Mars. On Earth she enters the scanner
which scans her body and brain cells in great detail at an instant of time,
down to all molecular details that are functionally relevant. At the same
time, her body is instantly destroyed, and the scanned data is sent to the
replicator station located at the journey’s target. There, the replicator
instantly builds a perfect copy of Abby’s body and brain, based on the
transmitted data.
Clearly the material body is destroyed (and rebuilt) in this process, which
leads to instant feelings of unease to most guinea pigs or humans who think
about this scenario. However, if the guinea pigs accept the conclusion from
the previous section (and so will we for the rest of this paper), then
there is no need to worry: Abby’s information content is replicated
perfectly. The state of the replicated brain on Mars will be a successor
state of Abby’s state on Earth in the sense of Informal definition 3.2.
Hence Abby’s first-person perspective of temporal experience will persist.
The previous argumentation has already brought us a long way into
unintuitive and discomforting territory; we have to go one step further to
make real progress and draw surprising conclusions. This will be done via a
particular thought experiment, inspired by the Star Trek episode “The Enemy
Within”. It has been described before in similar form by Parfit [65].
Thought experiment 4.1 (Teleporter malfunction). Like every morning, Abby
the guinea pig uses a teleporter to travel to her workplace at a hay farm
on Mars. The teleporter scans her body and brain cells in great detail at
an instant of time, down to all molecular details that are functionally
relevant.
