On 16 Nov 2009, at 17:45, Brent Meeker wrote:
> Bruno Marchal wrote:
>> On 11 Nov 2009, at 19:52, Brent Meeker wrote:
>>> But how is the "first person point of view" defined? Can this
>>> tell me how many persons exist at a given time?
>> I come back on this. The question "how many persons?" is a question
>> which remains very hard in the mechanist theory.
>> To answer it, let me ask you a question. Suppose that old fashioned
>> travel is possible, and that Brent Meeker of the future decides to
>> travel in the past, and to say hello to the younger Brent Meeker.
>> met in a kitchen and drink coffee. Nobody else is present in the
>> kitchen. How many person are there in the kitchen? What would you
>> I think this: if you answer one, then I will tend to say that there
>> only one person in the multiverse, but it manifests itself in
>> overlapping contexts. If you answer "two", then I will tend to say
>> there are an infinity of persons in the multiverse.
>> What do you think?
> I think closed time-like loops are probably impossible. But your
> just points to possible equivocation on "person". The time traveling
> Brent is a different person from the untraveled Brent because he has
> different memories just as the 70yr old Brent is a different person
> the 10yr old Brent. But in another sense - causal continuity - they
> the same person. It isn't necessary to introduce time travel to
> create this confusion of terms.
> But the first part of my question was about how a "first person
> view" is
> defined in this mathematical abstraction? What computations must my
> computer perform so that it has a first person view?
UDA has been constructed so that we don't have to answer this question
to understand that the physical laws emerge from numbers (assuming
It is just enough that we accept that there is a level of
substitution. Then we can prove that we cannot know-for-sure which
computations support consciousness, yet that we have to take into
account an infinity of those computations (below the substitution
level) to get the first person experiences measure.
But AUDA provides a hint of a more precise answer. Consciousness is
associated to the universal machine having the cognitive ability of a
Lobian machine(*). So PA and ZF are already conscious. Their
provability predicate obey Bp -> BBp. And their knowledge pseudo-
predicate defined by Kp = Bp & p, obeys it too: Kp -> KKp.
But remember that, by the movie graph (UDA step 8) consciousness is
not associated to the performance of a computer (= one computation/one
universal machine), but to the existence of the computations
(=infinity of computations and universal machines as defined in the
standard model of arithmetic). Consciousness is associated to the
logical relations between numbers which defined the alternate
consistent extensions of the "subject". You are, in that sense, the
same person as PA, and probably ZF, like you are the same person as
the young baby Brent.
And probably: rich qualia (like our owns) need long and deep stories
(very long computations capable of stabilizing on the interference of
the infinity of computations which exists below our level of
(*) Formally: it means they provability predicate obeys B(Bp -> p) ->
Bp (Löb Formula).
Bp -> BBp can be derived from this. It is actually done in Smullyan's
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To post to this group, send email to everything-l...@googlegroups.com.
To unsubscribe from this group, send email to
For more options, visit this group at