2009/1/29 Bruno Marchal <marc...@ulb.ac.be>
> On 28 Jan 2009, at 21:25, Quentin Anciaux wrote:
> 2009/1/28 Bruno Marchal <marc...@ulb.ac.be>
>> Hi Quentin,
>> > I was thinking about the movie graph and its conclusions. It
>> > concludes that it is absurd for the connsciousness to supervene on
>> > the movie hence physical supervenience is false.
>> OK. It is a reductio ad absurdo. It assumes that consciousness
>> supervenes on the physical activity of a brain (Phys. Sup.), it shows
>> that it leads to the fact that consciousness suoervenes on a movie
>> "qua computatio", and this is considered as an absurdity, and so it
>> concludes that Phys. Sup is false.
>> > But if I simulate the graph with a program, and having for exemple
>> > each gates represented by a function like "out = f(in)" each
>> > functions of the simulated graph is in a library which is loaded
>> > dynamically. I can record a run and then on new run I can
>> > selectively replace each libraries/functions by another one with the
>> > same function contract but which instead of computing the out value,
>> > it takes the value from the record. I can do it like in the movie
>> > graph for each gates/functions.
>> > Then it seems that means in the end the consciousness has to
>> > supervene on the record...
>> Why? Consciousness supervenes on the computation(s), not on his
>> physical implementation, be it with record or with the original modules.
>> > then it is the same conclusion than for physical supervenience. What
>> > is wrong ?
>> The physical supervenience. Consciousness does not supervene on any
>> implementation "in particular" of a computation. It supervenes on all
>> (immaterial) computations going through the (relevant) states. This is
>> in Platonia.
>> Tell me if I miss something, but it seems to me there is no problem
>> here. It is just, again, a problem if you believe in some physical
> The problem I see is that the movie graph is used to show that phys-sup is
> wrong (having as condition that I know consciousness is turing-emulable, as
> we have a "conscious" graph which is the physical implementation), the
> argument shows that consciousness does not supervene on this physical
> implementation because we should be forced to accept it also supervene upon
> broken graph + movie. But what I think with my exemple is that it does not
> supervene on the particular simulation of the functionnal graph nor does it
> supervene on the non-functionnal lookup record sumulation of the graph.
> I understand the thing is that it supervene on all computations not a
> particular computation... but I don't see how then movie graph rules out
> phys sup and not any kind of supervenience.
> Why would the movie graph rule out a notion of *computational*
> supervenience. We can keep comp and abandon materialism. We can still say
> yes to the digitalist doctor, by betting on our more probable
> relative computational histories.
Because here there was no "physical" graph at the start... it's just a
program and we replace various subpart of it which instead of computing make
a lookup. Now frow what you are saying I should understand that the program
is a "description" of a computation, not a computation and "consciousness"
supervene on computation but not description of computation ? Then I'm lost
about what is a computation ? I would thing a computation is the act of
"running" the program, execute each step and modifying the internal state.
I'm talking about a modified version of the movie graph where instead of
starting with a conscious physical gates machine, I start with a conscious
program and transform it accordingly (broken gates + projection of the film
in the movie graph, in my case, stub subpart which do a lookup instead of
computing the value)
> The absurdity with the movie graph is that it shows that associating
> consciousness to the *physical* implementation leads us to attribute
> consciousness to a description of a computation, and that is ridiculous.
> (Well at least, once you understand what is a (mathematical) computation, I
> think many are confused here, I will come back on this).
> Computations and descriptions of computation are related, but differs and
> are not of the same type, nor level. It is hard to be clearer without going
> through computer science. Probably more in my next post to Kim on the
> Seventh Step.
> I am not really sure I get your "ruling out all kinds of supervenience".
Because from what I understand (which is surely wrong) it's absurd at all...
(supervenience of consciousness) :
A supervenes on a set of properties B, if and only if any two objects x and
y which share all properties in B (are
must also share all properties in A (are "A-indiscernible").
> http://iridia.ulb.ac.be/~marchal/ <http://iridia.ulb.ac.be/%7Emarchal/>
All those moments will be lost in time, like tears in rain.
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