Hi Jacques,
>After having discussed with Bruno Marchal about our metaphysical ideas, I
>would like to summarize them and to note their similarities and their
>differences. (Bruno, please correct me if I said something wrong about your
>ideas).
>
>Both Bruno and me do not say we know the absolute truth. Bruno considers his
>thesis as a logical consequence of the hypothesis of mechanism (even I feel
>that this hypothesis seems probable to him). I consider my ideas as
>speculations and I think that particularly in such transcentental questions
>we cannot be sure to know the truth.
I do think mechanism is plausible. I do also think that mechanism could
be refuted.
(And I certainly think mechanism is fascinating ...).
>Bruno and me believe that there might be an infinity of description levels
>or approximative theories of the world, ...
OK. At least in a very large sense of "world".
> ... but according to Bruno's hypothesis
>of mechanism, there exist one level L at a finite depth which describes us
>completely,...
"completely" not in the logical sense, but in a "Shannon" or
code-theoretical sense, like a Xerox machine don't need an understanding
of the bible to make a copy of it.
I don't need a complete theory of "me". I doubt there is any ... (with
mechanism there are provably no such complete theory of "me" or "you", or
any universal computing machine).
>and according to my conception of the spirit, there is no such
>level.
Don't forget that I showed (or at least intended to show) that if there
is a level at which I can be duplicated, I can never prove or communicate
correctly that I know that level. So with mechanism there is no (in any
provable way) such level (although it exists, by definition with Mech in
a highly non constructive sense of "exist").
>See http://www.website2u.com/log/text/reflmph/english/naturesp.htm :
>"whatever is the degree of precision reached by a theory, there would always
>remain a part of unknown, of undetermination, which would let a place for
>spirit".
I don't understand the link between indetermination and spirit. And also,
if there is such a level, there will be, from the point of view of the
observer, necessary indetermination too, for, if the observer is a
machine, it will necessarily ignore which machine it is.
>According to Bruno, at this level L, our choices are determinated by the
>laws of physics, but at this level, we do not exist : in fact I do not chose
>but the laws of physics chose what my body does.
I think that here you confuse context of the discussion. Remember that
with mechanism, if I am correct, it is (our belief in) the law of physics
which are supernening on the possible computationnal histories ...
But, there, we were discussing free will, and what I was saying, is that,
at the local "physical" level (let us say), we are indeed "obeying
physical law", but we are not living at that level : just remember the
poorness of the lawyer argument : "my client is not guilty, he was just
following the law of physics".
I don't think the free will question is related to the
indeterminisme/determinisme problem. I guess free-will is related with a
kind of self-perception of our relative ignorance, and with the question
of making decision with incomplete information, + the personnal taste,
history, etc. I guess it is also linked whit the recognition of our high
"degree of freedom".
With Mech there is also (of course) a level -the arithmetical level-
where there is no free-will, but we are not living at that level.
>Here I have some
>difficulties to accept the idea of Bruno which considers that we are free
>because we cannot know which machine we are. Is it a real freedom or an
>illusion of freedom ?
It is real freedom because we are necessarily ignorant of which machine
we are and we will be. It is even a constructive ignorance in the sense
that if you pretend I am such or such machine, I can (at least in
principle) contradict your statement.
But sometimes, by introspection, I doubt I have free-will, or I doubt
there is a genuine meaning for the word. Indeed, I never succeed doing
something really for free. There is always a web of (conscious or less
conscious) reason to act as we do.
In Mind's I (edited bay Hofstdtate & Dennett) there are very interesting
paradoxical stuff on free will by Smullyan).
>According to my conception of spirit, at any level our choices are not fully
>determinated by the approximative laws corresponding to this level, so we
>exist, but the more the level is deep, the more we "become small".
So what ? If at any level we are not determined, then the only thing you
will get is a kind of pure and objective randomness. But I think there is
less room for free-will with randomness than with anything else. A random
choice is not at all a free choice.
>Bruno says that if we look at a level deeper than L, we see a fuzzy reality
>(like in quantum physics, but it seems to me that it's fuzzy until we
>observe it : when we make a measurement, we get a determinate value) : our
>consciousness supervenes on several parts of the Universal Doveteller (the
>program which runs all programs) which are so near that we don't perceive
>any difference. But if we look under the level L, there are some differences
>between these parts of the U.D. Bruno compares this with lucid dreaming.
Indeed. This is also nicely illustrated by the science-fiction novel by
Galouye : SIMULACRON 3, where the hero begin do detect the virtual nature
of his environment by looking at curious feature of his neighborhood.
>This made Bruno say that paradoxically my conception is more determinist
>than his conception, because in my conception we cannot find such a level
>below L in which the reality is not determinated.
>According to Bruno, the world is less determinated than the spirit.
If we interpret the word "world" as a relative machine dream (or
history), and if we interpret spirit by arithmetical truth : then I agree
with you.
I am not sure you are willing to accept these interpretations. Please
tell me.
>According to me, the spirit dives down to the deepest levels of the world
>and therefore has an absolute existence.
I should (re)read your web pages. I am not quite sure what you mean here.
>A problem raised by Bruno's idea according to which our consciousness
>supervenes on an infinity of parts of the U.D. is to explain why the world
>seems coherent. Why for example the table in front of me does not fly in the
>air in most of the parts of the U.D. on which my consciousness supervenes ?
>I suggested to Bruno that in these worlds, other strange things will
>probably happen, for example my brain will explode, and I will not be able
>to perceive anything in these worlds. Bruno has another interesting
>explanation : he thinks that the coherent worlds are infinitely more
>numerous because there is a continuous infinity of such worlds (Aleph 1) and
>there are only an enumerable infinity (Aleph 0) of incoherent
>("pathological") worlds.
I hope so. But this remains to be proved, ... or disproved. In which case
Mechanism will be refuted.
Cheers, Bruno.
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Received on Mon Jan 25 1999 - 03:07:08 PST