Now that I've written the previous post, I noticed the addressee on yours, and it occurred to me that you probably weren't talking to me. Oh well. I think it's a useful post whether you want my opinion or not.
-- Russ Abbott _____________________________________________ Professor, Computer Science California State University, Los Angeles o Check out my blog at http://bluecatblog.wordpress.com/ On Thu, Jun 11, 2009 at 11:33 PM, Russ Abbott <[email protected]> wrote: > Hi Nick, > > See below. > > -- Russ > > > On Thu, Jun 11, 2009 at 9:48 PM, Nicholas Thompson < > [email protected]> wrote: > >> Russell, >> >> So, is it Bedau and Philllips you have at hand? I am hoping to get some >> of >> my colleagues in Santa Fe to read that with me next fall. > > > It's Bedau and > Humphreys<http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=11341>. > > > >> >> >> If that is the source you are using, I also had Bedau's contribution to >> this volume in mind when I made the comment below. >> >> I am going to key in some short passages below so we can go over them >> together. >> >> He writes that [strong] emergent properties are supervenient properties >> with irreducible causal powers"...some of which are "macro-to-micro" >> effects[,] termed "downward causation". >> >> Supervenience means, as i understand it, that while each member of some >> enumerable list of microstates is sufficient for the occurence of the >> emergent macrostate, no one of those states is necessary for its >> occurence. >> So in practice one can have many different micro states that can bring >> about the macrostate, but no change in the macrostate without some change >> in a microstate. > > > The necessary and sufficient part isn't part of the definition of > "supervenient." The definition is simply your last clause: no change in the > macrostate without some change in a microstate. > > >> >> Downward causation means, as I understand it, that some macrostates are >> sufficient for some microstates. This brings about the loopiness that some >> of the authors in the book regard as inspired and others regard as >> vicious. >> [Some will argue that if a microstate is sufficient for A macrostate and >> that macrostate is sufficient for a microstate then the macrostate drops >> out of the equasion and we need simply point out that the first microstate >> is sufficient for the second. } >> >> Bedau then writes: "Such [macro] causal powers cannot be explained in >> terms of the aggregationof the micro-level potentialities; they are >> primtive or "brute" natural powers that arise inexplilcably withthe >> existence of certain macro-level entitites." >> >> Which led to my comment that they are, by definition, inexplicable. > > > I understand downward causation to refer to a new causal power. An example > might be dark energy. It causes changes in the universe even though there > are no micro explanations for it. If it operates only at cosmological scales > (and not just because it is weak at other scales, but it simply doesn't > exist at other scales) then it exhibits downward causation. Another example > is vitalism, were it true. It would say that there are new causal powers at > the biological level that simply come into existence at that level and are > not explicable in terms of lower level forces. > > >> >> Bedau goes on to write, "All the evidence today suggests that strong >> emergence is scientifically irrelevant." and goes on to argue that no >> essentially examples exist. In othere words, strong emergence is >> possible, >> it just has never been observed. This seems a very strange resolution of >> the argument, since it seems to define emergence in terms of our inablity >> to explain something, rather than in terms of some measurable property of >> the thing itself. This seems very close to the "surprise" argument that >> Bedau rejects in the early pages of the same article. >> > > His argument is really a rejection of vitalism. No one wants to be a > defender of vitalism, which is the rejected poster boy of downward > causation. > > I've never seen anyone talk about dark energy in this context. It might be > a more respectable candidate for downward causation. But it's not likely -- > in my opinion. It's conceivable that dark energy is a new force of nature > and that it's different from the other known forces -- gravity, > electromagnetic, strong, and weak.But even if that were the case, if it > could be shown to exist at all scales -- or perhaps like time and gravity -- > to be simply a part of the structure of the universe, it wouldn't qualify as > downward causation. Downward causation requires that the new force pop into > existence when and only when some macro condition holds but not as a > consequence of the micro conditions that make it up. > > >> More on this tomorrow, I hope. >> >> Nick >> >> >> >> Nicholas S. Thompson >> Emeritus Professor of Psychology and Ethology, >> Clark University ([email protected]) >> http://home.earthlink.net/~nickthompson/naturaldesigns/<http://home.earthlink.net/%7Enickthompson/naturaldesigns/> >> >> >> >> >> > [Original Message] >> > From: russell standish <[email protected]> >> > To: <[email protected]>; The Friday Morning Applied Complexity >> Coffee Group <[email protected]> >> > Date: 6/12/2009 3:17:44 PM >> > Subject: Re: [FRIAM] quick question >> > >> > On Thu, Jun 11, 2009 at 07:01:38PM -0600, Nicholas Thompson wrote: >> > > Steve, >> > > >> > > My understanding of the meaning of "strong" emergence is "inexplicable >> > > emergence". >> > > >> > > Is there another meaning? >> > > >> > > N >> > >> > Bedau defines it as emergence with downward causation. For example, we >> would say >> > that consciousness is strongly emergent if we felt that we could >> > consciously influence the activities of our neurons, rather than >> > simply our consciousness simply being the result of neuronal activity. >> > >> > I'm not sure this notion has any use in discussions other than >> > consciousness, and even there the notion of epiphenomenalism would say >> > that it is void concept. >> > >> > Cheers >> > >> > -- >> > >> > >> >> ---------------------------------------------------------------------------- >> > Prof Russell Standish Phone 0425 253119 (mobile) >> > Mathematics >> > UNSW SYDNEY 2052 [email protected] >> > Australia http://www.hpcoders.com.au >> > >> >> ---------------------------------------------------------------------------- >> >> >> >> ============================================================ >> FRIAM Applied Complexity Group listserv >> Meets Fridays 9a-11:30 at cafe at St. John's College >> lectures, archives, unsubscribe, maps at http://www.friam.org >> > >
============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
