Marchal wrote:
> 
> Russell Standish wrote:
> 
> 
> 
> >In Occam's razor, I don't just ignore this problem, I sweep it under
> >the rug. At some stage I have said "Theories of Consciousness have
> >bogged down in a quagmire". I think I must have just said it, as I
> >cannot find it written in any publications. Perhaps I want to distance
> >myself somewhat from the mud-slinging going on.
> 
> 
> If treasures were not hidden in the mud, they would not be treasures :-)
> 

I suspect your words came out wrong here - do you mean "A treasure
hidden by mud is still a treasure"? Which, of course I agree with. I
would be ecstatic if someone developed a working theory of
consciousness. It would be a philosophical triumph. However, I'm
rather pessimistic of living to see such a theory (modulo QTI being
right of course :).

> 
> >Without providing a theory, or even a
> >definition of what consciousness is, in the paper I assume 3
> >propositions to be true about consciousness:
> >
> >i) It is capable of universal computation (in order to interpret)
> >ii) It experiences time (in order to compute)
> >iii) It "projects" out actual events from the set of potential events.
> 
> i) is ambiguous. And doubtful for most crisp interpretation I try.
> For exemple I believe cats are conscious. Cats are capable of universal
> computation only in a very large sense. Still I appreciate, but dangerous
> because most people will derive that animal are not conscious.
> 

In part, this is an effect of the organic nature of science. There are
at least 3 rejoinders to this:

i) Who is to say cats cannot perform universal computation. UC is in
fact a very common property in the universe.
ii) Who is to say that cats are conscious (in the sense of the
anthropic principle - ie sufficiently aware to "instantiate" a
universe).
iii) Universal computation is not necessary in order to obtain a
reasonable prior - the equivalencing mechanism mentioned in "On
Complexity and Emergence". Occam was originally written 18 months ago,
and revised in response to some criticism about 9 months ago. My own
understanding has moved on, but when a paper is under review for
publication, one shouldn't change any more than is necessary.

> ii) needs a definition of time. You will see how time emerges in my
> approach. It is linked to consciousness, and basicaly I would agree,
> although the subject of experience is a person and not consciousness,
> which is a qualitative state of that person experiencing time.
> 

I don't think the time here is too mysterious. All one needs is a one
dimensional parameter t, so one can write down an evolution
equation. That this time is a subjective experience, rather than
inbuilt into the "external physics" is the controversial aspect of
this. However, this seems to be the only of answering the objections
of (eg Julian Barbour, etc).

Besides, assumption i) Universal Compution, actually requires the
subjective experience of time in order for the computation to take
place. It's only upon relaxing this to the equivalencing mechansim,
that i) and ii) are independent postulates.

> iii) is a correct description of the appearances.
> 
> > [...]
> 
> >The reason I say this is that while homo sapiens is capable of
> >universal computation, it is not its primary modus operandi, hence I
> >would be surprised if the prior distribution of descriptions was given
> >by a universal computer.
> 
> I don't see the relation with the prior distribution. I guess I miss 
> something here.

The prior distribution is that the probability of observing a
particular description of the universe depends exponentionally on the
complexity of that description. Here complexity is defined using the
equivalence mechanism as set out in "Complexity and Emergence". In the
case where the equivalence class used is all descriptions
generating a particular output from a universal turing machine, then
the complexity measure is just the usual Kolmogorov complexity, and
the prior is just the usual Universal prior.


> 
> >One can criticse my work on 3
> >grounds:
> >
> >i) My conclusions do not follow logically from this basis 
> >ii) That there are additional hidden assumptions needed, that I've not made
> >clear or precise
> >iii) That one or more of the above assumptions are false
> 
> >[...]
> 
> >I'm am therefore, far more interested in errors of logic or
> >omission. It would seem that you would develop a criticism along the
> >lines of ii) - hidden assumptions, however I've yet to see these spelt
> >out (or perhaps they have, just I haven't understood it because of
> >language barriers).
> 
> 
> In fact I'm not sure what exactly are your assumptions. Are you talking
> on the assumptions about consciousness? 

Yes, plus the Kolmogorov axioms of probability, plus a minimal amount
from set theory needed to support these. Also, of course, that we're
dealing with the set of all descriptions, which is basically the same
as your "Arithmetical Platonism". And the Anthropic Principle.

> 
> I have still the feeling that you attach observers to universes.  
> You don't postulate comp, do you?

No I don't. However, my theory is compatible with COMP.

I still need to understand what you mean by "attaching observers to
universes". Do you mean that the observed universe needs to be
consistent with the fact that we are around to observe it? If so, then
yes I do assume it, ie the Anthropic Principle.

However, one way of justifying this is as follows - consider the
situation of us observing an extremely simple universe that cannot
support intelligent life. The observational fact of observing
ourselves observing would thus appear as a miracle, and the resulting
description has a very high complexity, leading to a vanishingly small
probability compared with the sort of universe that allows
intelligence to naturally develop.

This is fine, but one may then ask the question - why do we need to
observe ourselves? Obviously we do - but why isn't just observation of
an external universe sufficient. On this matter, I shall stay silent -
this is an open problem, I believe. One that I raised before in this
group. It is also related to the question of whether cats can be
"conscious" in this self-aware sense. To date, only humans, chimps and
dolphins are known to be self-aware (at least according to a
television news item from the other night).

> 
> Bruno
> 
> 
> 
> 
> 



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