Bruno Marchal wrote:
>> since an uploaded digital mind could also
>> be part of a lot of dreamy realities
> It is a part of a lot of "dreamy realities", without any uploading. By  
> definition of the body and of the digital level of substitution, if we  
> upload ourself in a computer, we conserve the same relative proportion  
> of the "dreamy realities".
Yes, if a correct substitution level exists. My point is that it in the
general case no digital substitution level can exists, because of a
self-referential loop between the substitution and the environment / between
the computation and the instantiation of the computation (see below for a
more detailed argument).

Bruno Marchal wrote:
>> Our brain avoids that by being a structure with a quite unique
>> instantiation,
> Current physics makes this very doubtful. Assuming QM, there is only  
> quantum clouds of brains. Unless you presuppose the old copenhagen QM,  
> which does not make sense to me.
I don't mean unique in a physical way, but in a subjective way. It is
subjectively easier to see the difference between brains, but harder to see
the difference between computers (that may be physically equal, but running
different code). The uniqueness of the brain is its uniqueness of subjective

Bruno Marchal wrote:
>> and a quite clear subjective dividing barrier to virtual
>> realities (I am not a/ in a computer).
> How do you know that?
I can't know that, indeed I suspect that even just my local personal self is
to some extent distributed among all computations.
I only say that I do not have a perspective of being a computer. When I look
at myself, I see (in the center of my attention) a biological being, not a

Bruno Marchal wrote:
>> It's harder to dinstinguish
>> yourself from other simulated selfes than from other biological  
>> selves,
>> because of the natural biological barriers that we have, that  
>> computers
>> lack.
> Ah?
I can see that I am physically/biologically seperate from you, while we
could be both simulated on one computer, without any clear physical dividing

Bruno Marchal wrote:
>> We can only say YES if we assume there is no self-referential loop  
>> between
>> my instantiation and my environment (my instantiation influences  
>> what world
>> I am in, the world I am in influences my instantiation, etc...).
> Why? Such loops obviously exist (statistically), and the relative  
> proportion statistics remains unchanged, when doing the substitution  
> at the right level. If such loop plays a role in consciousness, you  
> have to enlarge the digital "generalized" brain. Or comp is wrong,  
> 'course.
I think it is self-refuting if we not already take the conclusion for
granted (saying YES only based on the faith we are already purely digital).
Imagine substituting our whole generalized brain (let's say the milky way).
Then you cannot have access to the fact that the whole milky way was
substituted, because otherwise the whole milky way would have to appear to
be a computer running a simulation of the milky way, making our experience
drastically different (which is not possible, given that our experience
should remain invariant). But if we don't have access to the fact/the way
that we are being substituted, it makes no sense to say YES, because we
can't even say whether are being substituted. If a substitution is not
taking place subjectively, the question of saying YES becomes meaningless
(making COMP meaningless).
The only way we could know we are being substituted is if there is something
other than the milky way to communicate with (which can see we are being
substituted). But then we have no reason to suspect that this other will
remain invariant, because from its perspective we have shifted from being
the milky way to being a computer running a simulation of a milky way, which
is such a big difference that it will inevitably totally change its response
(to the point of not being the same other / the same relative world anymore
- a a totally different interaction s taking place).
Or we just *believe* we are being substituted (for whatever reason) and say
YES to that, without any evidence we actually are being substituted, but
then we are not saying YES to an actual substitution but to the conclusion
(I am just a digital machine that is already equal to the substitution).
Either way, our experience doesn't remain invariant, or we have no way to
state we are being substituted (making COMP meaningless).

How is that not a reductio ad absurdum?
The only situtation where COMP may be reasonable is if the substitute is
very similar in a way beyond computational similarity - which we can already
confirm due to digital implants working. 
This would make COMP work in a quite special case scenario, but wrong in

Bruno Marchal wrote:
>> OK, we could say YES based on the faith that subjective self- 
>> reference will
>> develop a world for the digital brain that is similar to the old world
>> (though that seems very unlikely to me), but this is not YES qua  
>> computatio.
> That is exactly the YES qua computatio. You let the artificial machine  
> handling the 3-person self-reference (at the hopefully right level),  
> and you bet you are still confronted with the local "persistant true  
> illusion".
This is impossible since 3-person self-reference behaves differently that
1-person self-reference. The computations may remain invariant (and thus 3-p
self-reference), but the implementation is not, and we can't avoid 1-p
reference to the implementation. If I am substituted with a digital brain,
the computations at first may be the same, but I can see that the
implementation has changed (if only indirectly through my environment),
making the computation different again.
An attempt of substitution leads to an infinite regress of self-reference. I
substitute myself at the right level, but then my implementation has changed
and I can see that, which necessarily changes the computations that are
going on. Then we have to change the substitution again (or take the change
of computations into account in the begining) if I see I am being
substituted. But this also has to be taken in to account... This infinite
regress could only terminate if at some point I can't know I am being
substituted, in which case there is no way to say YES to a substitution
(except as an exclamation of faith in the conclusion of COMP). This means
that according to COMPs assumption (YES) it can't terminate at a finite
number of steps, so we can't have a finite substitution level. But we would
need that in order to say YES. In any case, COMP is false in the general
COMP only works relatively if subjective self-reference *happens* to arrive
at a similar state of consciousness. But this is not (purely) due to the
computations that are going on. It is due to subjective self-referential

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