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Complexity and Life



There are complex systems and there are complex living systems (organisms). The (M,R)-System refers to a living system/organism because metabolism and repair are two abilities that living systems-- of any configuration-- must have in order to be alive-- and which atoms do not have. Yet atoms are complex systems.
 
Obviously, there are different types of complex organization; a fact which has never been fully described or "catalogued". I asked my father why that was and he said it never occurred to him to do so. Probably he felt it would send the wrong message; maybe people would think that if there are "levels" of complexity, then going from one level to another would be possible via some sort of addition or accretion. That kind of thinking is what he found fault with in Von Neumann's discussions about complexity-- that it would ever be possible to reach complex organization by adding to simple organization. This is something my father categorically stated was not possible. Adding complex systems together does not necessarily create a complex system-- complexity is in the organization, not in the components. Similarly, adding two organisms together doesn't necessarily create a new organism. It all depends on the organization of the new system and offhand, I can't think of any case where the new system would be of equal or greater complexity. Most of the time, what you have is a simple system or a chimerical complex system.
 
This was one source of major confusion on the old list because my father's statement that atoms are complex systems meant in some minds that all systems must be complex-- but that is not the case. A system's complexity (or lack of it) is determined solely by the organization of that system, not on the complexity of the parts. What my father said was that it is a complex universe; that complexity is a general feature of the universe. Some mistook that to mean that "all material systems in the universe are complex" which was not my father's belief.
 
On the question of what is necessary and what is sufficient...to create a life form or living system-- bear in mind that my father was being extremely careful. His choice of wording would reflect that caution. This ventures into the area he decided not to go in publication. He did not want to provide the equivalent of a "how to" manual. When I asked him if he thought he could do it himself, he said, "I think so." But he had no interest in testing himself to see whether he could. I didn't ask him how he would go about it, if he were to try.
 
Judith
 
 
    Clearly, Rosen was well aware of the Godelian implications for decidability of sufficiency conditions long before he wrote Q1 in Life Itself. So, I have always been puzzled why Q1, and the discussion surrounding it in that chapter, did not qualify the sufficiency condition in any way. Particularly if, as Aloisius suggests, Rosen saw it as a case of a necessary condition being "so close" to being a sufficient condition "that one may as well ACCEPT, or BELIEVE, that it is so", rather than for some more rigorously defensible reason. 
    As such, I do see the tenor of the sufficiency statement in Q4 as being a "softening", to put it mildly, from his sufficiency statement in Q1. Actually, in the way he phrases it using double negatives ("...I see no grounds for refusing..."), I would argue that it does not constitute a sufficiency condition at all. The assertion "I see no grounds for refusing to call such a realization an autonomous life form, whatever its material basis may be" is not at all the same as the assertion 'I see grounds for calling such a realization an autonomous life form, whatever its material basis may be'. I think his wording was precisely chosen so as to suggest a possible locus for a sufficiency condition without actually asserting one.
 
 
 
 
 
I'd be curious what Aloisius thinks of these comments.
 
Regards,
Tim