Re: Question

[John Kineman <***>]

Howard et al.,

This addresses the metaphysical difference I started to ask about before
reading this. I suppose I am obligated to comment having professed to be
interested.

Speaking entirely from the perspective of underlying beliefs about
reality, I see Langton's statement to be a little shallow on both sides,
in that he is throwing a bone to the idea that artificial life must in
some way be artificial. So, he says life must be associated with the
non-material part. If we have only this statement to work from, he is
also saying that non-material "logical form" is what he is representing
in a computer, and thus is a calculable form.

Now, RR, on the surface, said keep the "organization." We know from his
work that he expressly did not mean this as a calculable organization,
but as one that cannot be calculated, that incorporates impredicative
loops. Langton's logical structure does in fact simulate an
impredicative loop using iterative methods, but it becomes the same as
impredicativity only in the limit when the time step goes to zero.
Elsewhere, in Essays I believe, RR describes the difference in his view
of complexity by analogy with the idea of infinity. One may approach
very large numbers, but no large number is anything like the idea of
infinity.

Ultimately, if locked in a room, they may be made to agree, since
Langton would prabably admit that only in the limit does this get at
true complexity. But clearly he was involved in developing and applying
this iterative approach as a simulation of complexity. So, the remaining
question I have, and why I asked Howard to comment on the metaphysics,
is this. Does something very different occur at infinity? (or rather
when Langton's time step is zero)? Or are all such situations in fact
simulable by iterations with t>0??

In solving orbital dynamics one must deal with the n-body problem, and
my understanding is that is done by precisely this kind of simulation.
In that case, as t -> 0 one does expect the simulation to get very close
to reality. This works, as we can see on the NASA web site because we
did in fact get to Mars. But this is simulation of a physical system.
Would it be different for biology? I honestly don't have an answer. I
read RR as implying it would be different, but I don't know how.

In any case, however, I think this very question is what demarcates the
philosophies, aside from the degree to which each focused on the
problems of simulation vs. non-simulable life -- that should not be lost
here either, as a few comments are not equivalent to a life's work on
one side of this divide vs the another, regarding their depth of
understanding.

JJK



Howard Pattee wrote:

> Here is a question that I suspect will elicit several opinions:
>
> Rashevsky’s relational biology is the study of life at a level of abstraction that does 
> not address any particular material physical realization of life, but looks at its most general 
> logical organization. Rosen contrasts relational biology with reductionist biology in the 
> following words:
> “In any case, I can epitomize the reductionist approach to organization in general, and life in 
> particular, as follows: throw away the organization and keep the underlying matter. “The relational 
> alternative to this says the exact opposite, namely: when studying an organized material system, throw away 
> the matter and keep the underlying organization.” (LI, p. 119)
>
> Langton’s and other’s view of Artificial Life is that they also want to get beyond 
> particular material realizations of life. Langton says:
> “Of course, the principle assumption made in Artificial Life is that the ‘logical form’ of an organism can be 
> separated from its material basis of construction, and that ‘aliveness’ will be found to be a property of the former, 
> not of the latter.” (Artificial Life, Langton, ed., Addison-Wesley, 1989, p.11.)
>
> Question: What substantial philosophical differences do you see here, if any. Of course, the actual research programs are quite different.
>
> Howard

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© 2004 John J. Kineman
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