cowan@marob.masa.com (John Cowan) (09/21/90)
In article <3894@se-sd.SanDiego.NCR.COM>, jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin, Cognitologist domesticus) writes: >In article <59556@bbn.BBN.COM> BKort@bbn.com (Barry Kort) writes: >>As I see it, emotions are an emergent property of any learning system. >Not to flame, but I wish people would stop using the term "emergence". >I know they won't, but could you state what you mean? My assessment >of the idea of emergence is that it's not possible within our curernt >paradigm of science and rationality. The impression I get is that >people throw the term around when they need a hand-waving explaination >of some mental phenomenon. People certainly do abuse the term "emergent", but it does have a definite meaning. An emergent property is a property of a system that cannot be accounted for by the properties of the system components, relative to some level of explanation. For example: Nitric acid does not dissolve gold. Sulfuric acid does not dissolve gold. A mixture of the two, called aqua regia, does dissolve gold. This property is emergent at the level of commonplace understanding, namely that the properties of a mixture are a mixture of the properties of the components. At the level of acid-base chemistry, of course, the behavior of aqua regia is well understood. So emergent-ness does not make sense as a concept without reference to a level of understanding, either implied or stated. In the original article, the claim that "emotions are an emergent property of intelligent systems" means that emotions arise from the interactions of a set of components, none of which themselves possess emotion. -- cowan@marob.masa.com (aka ...!hombre!marob!cowan) e'osai ko sarji la lojban
jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin, Cognitologist domesticus) (09/26/90)
In article <26FA3460.1C7D@marob.masa.com> cowan@marob.masa.com (John Cowan) writes: >In article <3894@se-sd.SanDiego.NCR.COM>, jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin, Cognitologist domesticus) writes: >>Not to flame, but I wish people would stop using the term "emergence". >>I know they won't, but could you state what you mean? My assessment >>of the idea of emergence is that it's not possible within our curernt >>paradigm of science and rationality. The impression I get is that >>people throw the term around when they need a hand-waving explaination >>of some mental phenomenon. > >People certainly do abuse the term "emergent", but it does have a definite >meaning. An emergent property is a property of a system that cannot be >accounted for by the properties of the system components, relative to some >level of explanation. This sounds like "emergent = I don't know". Your definition I agree with, but I don't think it buys us anything. People usually throw this term around as if it means something when it really means "we don't know how this happens, only that it does". I've seen "emergence" used to try to "explain" things, but how can you explain something using a term that means "unknown"? - Jim Ruehlin p.s. I'll be posting all other responses to this conversation to comp.ai.philosophy.
smoliar@vaxa.isi.edu (Stephen Smoliar) (09/27/90)
In article <3918@se-sd.SanDiego.NCR.COM> jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin, Cognitologist domesticus) writes: >In article <26FA3460.1C7D@marob.masa.com> cowan@marob.masa.com (John Cowan) >writes: >> >>People certainly do abuse the term "emergent", but it does have a definite >>meaning. An emergent property is a property of a system that cannot be >>accounted for by the properties of the system components, relative to some >>level of explanation. > >This sounds like "emergent = I don't know". Your definition I agree with, >but I don't think it buys us anything. If we approach it properly (rather than using it as a euphemism for our own ignorance), it offers the possibility of some intellectual hygiene. Let me return, once again, to one of my favorite examples: the Darwin automata being investigated by Gerald Edelman's group at the Neurosciences Institute. The ability of a Darwin automaton to perform perceptual categorization is an emergent property. What this means is that one cannot point to some specific system component and say, "Here is where the knowledge to recognize the letter A resides." An outside observer will be able to note that there are parts of that automaton which exhibit similar behavior when confronted with various presentations of that letter, but one cannot to a Newell-style knowledge level analysis of the system. What does this have to do with intellectual hygiene? It is a lesson to remind us that much of artificial intelligence has run aground by virtue of our insistence on asking ill-formed questions. It confronts us with the possibility that, for example, asking for a set of necessary and sufficient conditions which will enable some kind of decision logic sitting behind a retina to recognize the letter A may be one of those ill-formed questions. This is not to say that it is giving us any answers. However, when we are having trouble finding answers to our questions, often we would do well to question those questions. The study of emergent properties provokes us to consider how some of those questions might be reformulated into once which might be more accommodating. ========================================================================= USPS: Stephen Smoliar USC Information Sciences Institute 4676 Admiralty Way Suite 1001 Marina del Rey, California 90292-6695 Internet: smoliar@vaxa.isi.edu "It's only words . . . unless they're true."--David Mamet
n025fc@tamuts.tamu.edu (Kevin Weller) (09/27/90)
In article <3918@se-sd.SanDiego.NCR.COM> jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin, Cognitologist domesticus) writes: > jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin, Cognitologist domesticus) writes: > >This sounds like "emergent = I don't know". Your definition I agree with, >but I don't think it buys us anything. People usually throw this term >around as if it means something when it really means "we don't know how >this happens, only that it does". I've seen "emergence" used to try to >"explain" things, but how can you explain something using a term that >means "unknown"? > >- Jim Ruehlin > >p.s. I'll be posting all other responses to this conversation to >comp.ai.philosophy. No, emergent DOES NOT mean "We don't know how, but it happens." Let me try out a more elaborate definition on you. There are some highly ordered systems in nature with properties which can have no explanation that is solely dependent on the properties of the individual components of the system. That is NOT the same thing as saying that we don't know how to explain them at the component level (although we may not [yet] know how to explain them at any level); it says that a pure component level explanation can *never* be complete, that we must also study *the way the system is put together* to come to an adequate explanation of the phenomenon. Paul Davies puts it best when he asks if a Beethoven symphony is nothing but a collection of notes or if a Dickins novel is nothing more than a collection of words (*). On one level of description, the novel is a collection of words, but is this all we need to know in order to fully appreciate it? There is so much more depth to be found if we only step back and take in the bigger picture! This is the origin of the phrase "the whole is greater than the sum of its parts." The same principle applies to the phenomenon of life, and by extension, to intelligence. Although I am most certainly alive, the individual atoms that I am made of can hardly be called living. Life is an _emergent property_ of the complex and highly organized way in which living systems are put together, and any serious study which tries to explain the higher-level aspects of life by purely reductionistic biochemistry is doomed to failure (not to say that biochemistry is useless; that's the opposite error, and I don't want to make that mistake either). Your confusion is undoubtedly related to the largely reductionistic approach science has historically taken, but the new physics seems to require a more "holistic" (now there's an often-abused word if I ever saw one, but it has its valid applications) approach. Some problems can be solved only by putting the pieces together. The human brain is one of the most (if not *the* most) complex organized system presently known to exist. The complex patterns of operation in this highly organized system are the physical expressions of intelligent information processing. As others have stated in previous articles, my individual neurons may be no more intelligent than those of, say, an earthworm, so we cannot appeal to neuron physiology exclusively to explain my intelligence (assuming you believe I am intelligent, of course :-) ). They are part of the total explanation, but the rest is due to the properly ordered construction of the components into a working whole. Human beings are truly moving collections of atoms, but not *merely* moving collections of atoms. Magic is not invoked here. In fact, this functionalistic understanding precludes any need for a magical life-aura at all (not to say that there isn't any such thing, but by Ockham's Razor, it becomes an unnecessary annex to the concepts of life and intelligence). -- Kevin L. Weller (philosopher, computer programmer, etc.) (*) Davies, Paul. _God and the New Physics_. New York: Simon, 1983. And no, this is not another _Tao of Physics_ Shirley MacLain-type (sp?) book! Davies gives an essentially unbiased discussion of the impact of the new physics on modern religious AND scientific thought. I would recommend it to anyone interested enough to pursue the topic in earnest.
n025fc@tamuts.tamu.edu (Kevin Weller) (09/27/90)
Looks like I forgot to alter the Newsgroups field in my previous, long article which was meant for comp.ai.philosophy. Apologies to any comp.ai readers who might have been inconvenienced.
byland@iris.cis.ohio-state.edu (Tom Bylander) (09/27/90)
In article <15132@venera.isi.edu> smoliar@vaxa.isi.edu (Stephen Smoliar) writes: >... one cannot point to some specific >system component and say, "Here is where the knowledge to recognize the letter >A resides." An outside observer will be able to note that there are parts of >that automaton which exhibit similar behavior when confronted with various >presentations of that letter, but one cannot to a Newell-style knowledge level >analysis of the system. As I understand it, a knowledge-level analysis of a system specifies what knowledge can be ascribed to the system based on its external behavior. There is no problem in ascribing "the knowledge to recognize the letter A" to machines that actually recognize the letter A, no matter how the machines are constructed. Talking about the knowledge within components of a system is what Newell called a "mixed model" (which is elaborated upon by Sticklen's JETAI article "Problem Solving Architecture at the Knowledge Level"). The structure of the components and their interaction are described at the symbol level, and the components themselves are described at the knowledge level. In this style of analysis, one must be careful. Knowledge can be ascribed to a component only if the component by itself *behaves* as if it has the knowledge. Merely having a representation of the knowledge is insufficient because, for appropriate behavior to occur, some other component is needed to use the representation. So I would reword your first claim quoted above as follows: "One cannot point to some specific system component and say, `Here is where the knowledge to recognize the letter A is *represented*'". I don't why this kind of situation is so surprising because it is true for most ordinary programs. For example, a sorting program "knows" that less-than is transitive, but, for typical sorting algorithms, it is not possible to point out a "component" that represents this knowledge. (Knowing transitivity would appear to be an "emergent" property of sorting algorithms.) Finally, I don't think you want to claim that "one cannot do a Newell-style knowledge level analysis" of such systems or their components. Certainly, it might be difficult to determine how the component interaction results in recognizing the letter A, but this is a problem of symbol-level analysis. With regard to ascribing knowledge to components, I understand why it is difficult (because it requires considerable experimentation and analysis), but not why it is impossible. Tom Bylander
fostel@eos.ncsu.edu (Gary Fostel) (09/28/90)
Some of the recent posts have criticised the term "emergent property"
as a euphamism for "we don't understand" and some have defended the
term by examples of the application of the term and some have tried
to justify the term as a valid one more abstractly.
If I assemble a device from wheels, pedals, metal tubes and such,
and it happens to become the most efficient transportation device
around, is that an emergent property of the parts? I doubt that
defenders of the term would like it to be so. But why not? Probably
because the transportation property was a goal of the design process
that controlled the assembly. Now suppose a Venusian engineer viewed
this as a process of putting wheels, metals tubes, pedals, and an
engineer, and a few tools, in a room. These "parts" may well have
an emergent property, from the perspective of the Venusian, since
they had no expectation of a transportation function arising from
the collection of parts. (Yes the engineer is a part in this view.)
I identify this as an emergent property because I believe it would
satisfy most of the ad hoc definitions I have heard.
I do not expect most supporters of the "emergent property" term to
like this use of the term. They will not like it (I am guessing of
course) becuase they will feel that they can identify the source
of the property which has emerged ... but of course the Venusian,
having utmost contempt for the large water based carbon compound in
with the metal parts, will not be able to identify the source and
the "emergence" is viewed from that creatures perspective.
A second example: if you put large pine forrests, rabbits and foxes
together in northern Canada, you will get a 10 year cycle of boom
and bust in the populations of rabbits, foxes and young pine trees.
(Rabbits LOVE to eat pine needles, far more than carrots.) Is this
pattern an emergent property? From the perspective of a naive and
innumerate individual, the answer is certainly yes. The cycle is
there, it was not predicable (by them) and it is not easy to
identify the source in myopic analysis of rabbits, foxes, or pines.
From the perspective of an ecologist or someone versed in simple
dynamical systems theory, it is not an emergent property. It can
be predicted, modeled, and well explained, based on properties of
the constituent elements, e.g. kilocalories needed, supplied,
gestation period, etc.
Again, I would expect advocates of the "emergent property" term to
be somewhat bothered by this situation, but I believe it is because
they will tend to automatically associate with the technically
astute view of the dynamics. Two hundred years ago, ecologists
knew it happenned but did not understand at all why.
But, it was not called "an emergent property of rabbits, foxes and
pines". It was simply an unexplained experimental observation. That
does not have nearly the same gloss, but it is more accurate. By
saying that X is an emergent property of {A,B,C...} and by providing
some sort of definition for the term "emergent" an unsubstantiated
conclusion has been reached. A few people seem to make this part
explicit in the use of the term, directly or indirectly saying the
explanation WILL NOT come from reductionist methods, not simply that
it HAS NOT come from that source. Certainly, in the case of neural
systems (real or synthetic) it is not known that a suitable means
of reductionist explanation will not be found. Just that it has not
been found.
(So-called "chaotic systems" are an interesting counter point, since
there is some analytic evididence that there are classes of systems
for which it is not possible to predict specific behavior, based on
ANY measurement of the system. But in these cases, it IS often
possible to characterize the sorts of behavior that the system is
capable of. I take it that emergent properties deal in the currency
of behavior characterizations, not specific predictions, so the
behavior of a chaotic system is not an "emergent property".)
People studying intelligent systems seem to operate as if they already
know what the suitable "atoms" of the systems are. Since they
are unable to explain the observations based on properties deduced
from these atoms, they reach for terms such as "emergent properties"
rather than doing good science and looking to reformulate the basic
hypothosis in new ways. Hiding behind a pseudo-science of "emergent
properties" will probably delay the real struggle: to find more
suitable analytic tacts and more suitable atoms to form the
foundation of a "proper" scientific explanation.
I doubt advocates of "emergent properties" will like that either.
----gary----
sarima@tdatirv.UUCP (Stanley Friesen) (09/28/90)
In article <3918@se-sd.SanDiego.NCR.COM> jim@se-sd.SanDiego.NCR.COM (Jim Ruehlin, Cognitologist domesticus) writes: >In article <26FA3460.1C7D@marob.masa.com> cowan@marob.masa.com (John Cowan) writes: >>An emergent property is a property of a system that cannot be >>accounted for by the properties of the system components, relative to some >>level of explanation. > >This sounds like "emergent = I don't know". Your definition I agree with, >but I don't think it buys us anything. I do not think this is what John Cowan meant by his definition, nor is it what I mean by 'emergent'. Another way to put it is that an emergent property is one that makes the whole into more than the sum of its parts. We could quite well know how the parts combine to cause the added property. In fact, I would maintain that the term is only legitimately used where there is at least an educated guess about the mechanism of emergence. Thus if I say (and I do) that self-awareness is an emergent property of a system with a certain level of 'intelligence', I mean that I can see a mechanism by which the various compinents of intelligence combine to cause the phenomenon that we call self-awareness, but that it is not inherent in the descriptions of the individual components of intelligence. > People usually throw this term >around as if it means something when it really means "we don't know how >this happens, only that it does". I've seen "emergence" used to try to >"explain" things, but how can you explain something using a term that >means "unknown"? And I would say this is a mis-use of the term, and is the reason why it is so controversial. -------------------- uunet!tdatirv!sarima (Stanley Friesen)
cowan@marob.masa.com (John Cowan) (09/28/90)
In article <1990Sep27.185805.21493@ncsuvx.ncsu.edu>, fostel@eos.ncsu.edu (Gary Fostel) writes: > > Some of the recent posts have criticised the term "emergent property" > as a euphamism for "we don't understand" and some have defended the > term by examples of the application of the term and some have tried > to justify the term as a valid one more abstractly. I'm not sure which camp I fall into, as I gave both an abstract definition and a concrete example (aqua regia). > If I assemble a device from wheels, pedals, metal tubes and such, > and it happens to become the most efficient transportation device > around, is that an emergent property of the parts? Not exactly. It is an emergent property of the whole transportation system, because "most efficient ... around" is a notion that depends critically on what else is around. You certainly cannot (on the explanatory level of common understanding) point to any part of the transportation system and say "This part makes bicycles the most efficient". You can only do that on the explanatory levels of mechanics + thermodynamics. > I doubt that > defenders of the term would like it to be so. But why not? Probably > because the transportation property was a goal of the design process > that controlled the assembly. Now suppose a Venusian engineer viewed > this as a process of putting wheels, metals tubes, pedals, and an > engineer, and a few tools, in a room. These "parts" may well have > an emergent property, from the perspective of the Venusian, since > they had no expectation of a transportation function arising from > the collection of parts. (Yes the engineer is a part in this view.) > I identify this as an emergent property because I believe it would > satisfy most of the ad hoc definitions I have heard. I agree. On the explanatory level of the Cytherean ("Venusian" is a barbarism, on all fours with "Marsian", "Earthian", or "Jupiterian"), who does not recognize the human engineer as a purposeful system. Again, the concept "emergent property" makes no sense without reference to a level of explanation. > I do not expect most supporters of the "emergent property" term to > like this use of the term. They will not like it (I am guessing of > course) becuase they will feel that they can identify the source > of the property which has emerged ... but of course the Venusian, > having utmost contempt for the large water based carbon compound in > with the metal parts, will not be able to identify the source and > the "emergence" is viewed from that creatures perspective. Right. > A second example: if you put large pine forrests, rabbits and foxes > together in northern Canada, you will get a 10 year cycle of boom > and bust in the populations of rabbits, foxes and young pine trees. > (Rabbits LOVE to eat pine needles, far more than carrots.) Is this > pattern an emergent property? From the perspective of a naive and > innumerate individual, the answer is certainly yes. The cycle is > there, it was not predicable (by them) and it is not easy to > identify the source in myopic analysis of rabbits, foxes, or pines. > From the perspective of an ecologist or someone versed in simple > dynamical systems theory, it is not an emergent property. It can > be predicted, modeled, and well explained, based on properties of > the constituent elements, e.g. kilocalories needed, supplied, > gestation period, etc. Exactly. This fits in with my original statement about aqua regia. At the level of commonplace understanding of mixtures, "aqua regia dissolves gold" is an emergent property. At the same level, OTOH, "salt water dissolves sugar" is a resultant (non-emergent) property, because it depends on the minor premise "water dissolves sugar" and the major premise "the properties of mixtures are a mixture of the properties of the things mixed". At the level of acid-base chemistry, to say nothing of more detailed levels (quantum mechanics, e.g.) this property of aqua regia is resultant, because there is a complete explanation at the component level. In your example, the corresponding levels of explanation are "naive" and "dynamical systems theory". Consider Hofstadter's joke about how to fix the timesharing system that works fine with 35 on-line users but starts thrashing with more: poke around in the kernel, find the "35" and change it to a "60"! That this procedure does not work is evidence that the number 35 is an emergent property; it cannot be explained at the level of "kernel tuning parameters". OTOH, at the level of "tuning parameters" you can fix such superficially analogous problems as "this system provides 20 files per process fine, but chokes when 21 are required". In this case, we really do just need to change the 20 to a 21 (and recompile the kernel). This obviously does NOT mean that there is no explanation at ANY level of why 35 is the simultaneous user limit. It simply means that AT THE SPECIFIED LEVEL OF EXPLANATION, we don't know why. So you are correct that "emergent property" states a negative, but the negative is by no means absolute. Someone who understands the kernel time-slicing algorithms, the speed of the disk drives, the details of the various simultaneous jobs, etc. etc. will come up with a very good understanding -- perhaps even an analytic model -- that predicts the onset of thrashing. It's just that that kind of information is hard to gather and harder to validate. Most precisely, the claim that "P is an emergent property" states a limitation on the power of a given explanatory framework, to wit: it cannot account for P. Whether one looks for a more powerful framework, shrugs and accepts the unexplained fact, or just buys a faster disk drive depends on one's purposes, a matter outside the scope of this discussion. -- cowan@marob.masa.com (aka ...!hombre!marob!cowan) e'osai ko sarji la lojban
BKort@bbn.com (Barry Kort) (09/28/90)
In article <1990Sep27.185805.21493@ncsuvx.ncsu.edu> fostel@eos.ncsu.edu (Gary Fostel) writes: > If I assemble a device from wheels, pedals, metal tubes and such, > and it happens to become the most efficient transportation device > around, is that an emergent property of the parts? A good example of an emergent property in automotive engineering is the Cruise Control System. Like the centrifugal speed governor found on steam engines, this feedback control device regulates the behavior of the machine under unpredictable variations in load. In feedback loops, there is something ethereal flowing around the loop: Information. This information is not found in the piece parts themselves, but arises out of the pattern of interactions among the parts. Barry Kort Visiting Scientist BBN Labs Cambridge, MA
n025fc@tamuts.tamu.edu (Kevin Weller) (09/29/90)
In article <1990Sep27.185805.21493@ncsuvx.ncsu.edu> fostel@eos.ncsu.edu (Gary Fostel) writes: > > Some of the recent posts have criticised the term "emergent property" > as a euphamism for "we don't understand" and some have defended the > term by examples of the application of the term and some have tried > to justify the term as a valid one more abstractly. > > If I assemble a device from wheels, pedals, metal tubes and such, > and it happens to become the most efficient transportation device > around, is that an emergent property of the parts? I doubt that > defenders of the term would like it to be so. But why not? Probably > because the transportation property was a goal of the design process > that controlled the assembly. Your example is indeed in harmony with my definition of emergence since, for instance, a metal tube can hardly be said to have an "efficient transportation device" property in miniature! The property is of the whole system, not of the parts. This is not to say that the properties of the tube at its own description-level (or at lower levels still) don't play a part; that would be the opposite one-sided view. Whether the transportation property was a design goal or not is simply beside the point, just as the ultimate goal of AI researchers has no destructive effect on the intelligence in any systems they design/build (other factors can have destructive effects, of course). Emergent properties are simply properties, independent of the designer's (or designers') plans. Your device is probably not the BEST example of emergence because the "transportation device" description-level is not that much higher (more complexity-abstract) than the component level(s), but it does serve as a simpler analogue of more complex systems. > Now suppose a Venusian engineer viewed > this as a process of putting wheels, metals tubes, pedals, and an > engineer, and a few tools, in a room. These "parts" may well have > an emergent property, from the perspective of the Venusian, since > they had no expectation of a transportation function arising from > the collection of parts. (Yes the engineer is a part in this view.) > I identify this as an emergent property because I believe it would > satisfy most of the ad hoc definitions I have heard. You are correct again regarding the emergence in this example, only from another level of description (that of the Venusian). > I do not expect most supporters of the "emergent property" term to > like this use of the term. They will not like it (I am guessing of > course) becuase they will feel that they can identify the source > of the property which has emerged ... but of course the Venusian, > having utmost contempt for the large water based carbon compound in > with the metal parts, will not be able to identify the source and > the "emergence" is viewed from that creatures perspective. Your guess (concerning my "not liking" this usage) is wrong. Your illustration is perfectly compatible with my understanding of emergence, although as I said before, it is not the most useful application of the term. However, it does bring up one aspect of emergent properties that I failed to address in my original posting (sorry). There are usually many different ways to describe an organized system, these different ways corresponding to different levels of abstraction, called description-levels. For example, the collective behavior of an ant colony is considerably more complex and purposive than that of the individual ants, so at one description-level, we have a bunch of ants which are each behaving on the relatively simple level of programmed automata, while at the colonial level of description the whole is acting for a larger purpose, and often doing a fantastic job of it. There may be other examples more effective for you in getting the point across, but to keep this posting from getting TOO long, I'll put references at the end of the article. The key points are: physical systems in the universe vary in their complexity and organization, the simpler systems requiring much fewer (and lower) description-levels than the more ordered ones; and emergence is always RELATIVE to whatever description-level is being considered, so that the more removed a property is from those of the system's constituent parts, the more useful the term is in describing the synergistic effect of their ordered combination. THERE IS NO CONFLICT between the hardware and the software description-levels. They are complementary. I suspect that if we ever manage to build an artificial intelligence, the construction will involve some combination of knowledge from several levels of description (physics, chemistry, neurophysiology, cognitive science, etc.). > A second example: if you put large pine forrests, rabbits and foxes > together in northern Canada, you will get a 10 year cycle of boom > and bust in the populations of rabbits, foxes and young pine trees. > (Rabbits LOVE to eat pine needles, far more than carrots.) Is this > pattern an emergent property? From the perspective of a naive and > innumerate individual, the answer is certainly yes. The cycle is > there, it was not predicable (by them) and it is not easy to > identify the source in myopic analysis of rabbits, foxes, or pines. > From the perspective of an ecologist or someone versed in simple > dynamical systems theory, it is not an emergent property. It can > be predicted, modeled, and well explained, based on properties of > the constituent elements, e.g. kilocalories needed, supplied, > gestation period, etc. > > Again, I would expect advocates of the "emergent property" term to > be somewhat bothered by this situation, but I believe it is because > they will tend to automatically associate with the technically > astute view of the dynamics. Two hundred years ago, ecologists > knew it happenned but did not understand at all why. > > But, it was not called "an emergent property of rabbits, foxes and > pines". It was simply an unexplained experimental observation. That > does not have nearly the same gloss, but it is more accurate. By > saying that X is an emergent property of {A,B,C...} and by providing > some sort of definition for the term "emergent" an unsubstantiated > conclusion has been reached. A few people seem to make this part > explicit in the use of the term, directly or indirectly saying the > explanation WILL NOT come from reductionist methods, not simply that > it HAS NOT come from that source. Certainly, in the case of neural > systems (real or synthetic) it is not known that a suitable means > of reductionist explanation will not be found. Just that it has not > been found. On the contrary, I am not bothered by it at all. Your example is simply not one of emergence. I don't claim that ALL such phenomena are emergent. What I am trying to say is that SOME phenomena CAN NOT be explained SOLELY on the basis of component properties. If this weren't so, we would be capable of explaining every phenomenon using microphysics alone if given a total knowledge of all physical laws (or perhaps the much-sought-after Grand Unified Theory). But you say, of course, since all the other sciences derive from the most fundamental (i.e., REDUCED) law(s) of nature! Then, would you be willing to say that we should abandon all studies in chemistry, biology, meteorology, and so on in favor of physics alone? It would explain everything, wouldn't it? ONLY AT ITS OWN LEVEL OF DESCRIPTION! Think about it. Individual memories are not perfectly localized in the brain, but rather, they are stored as "tendencies" of the overall network to approximate patterns functioning for memories (a distributed memory system). My having a memory is represented on the hardware description-level by a pattern of electro-chemical processes in my brain. You can scrutinize the individual operating neurons to your heart's content and never see the full significance of the event. It's the *pattern* that counts on this description-level, and you must step back and look at the whole system to see the operation. Note that I am not advocating any kind of dualism here. Different levels of abstraction can all be referring to the same stuff, so if anything, abstraction-level is more of a monistic concept. It is philosophically classified as a form of materialism, but, of course, any good physicist knows the difficulty in defining "matter" and distinguishing materialism from "spiritism" of a sort. > (So-called "chaotic systems" are an interesting counter point, since > there is some analytic evididence that there are classes of systems > for which it is not possible to predict specific behavior, based on > ANY measurement of the system. But in these cases, it IS often > possible to characterize the sorts of behavior that the system is > capable of. I take it that emergent properties deal in the currency > of behavior characterizations, not specific predictions, so the > behavior of a chaotic system is not an "emergent property".) I'm not clear on what you mean by "currency of behavior characterizations," but I can say that chaotic systems are composed of components that obey physical laws just like components of ordered systems. However, the only true high-level properties of such a system to count would probably be its very chaos and its range of possible behaviors. > People studying intelligent systems seem to operate as if they already > know what the suitable "atoms" of the systems are. Since they > are unable to explain the observations based on properties deduced > from these atoms, they reach for terms such as "emergent properties" > rather than doing good science and looking to reformulate the basic > hypothosis in new ways. Hiding behind a pseudo-science of "emergent > properties" will probably delay the real struggle: to find more > suitable analytic tacts and more suitable atoms to form the > foundation of a "proper" scientific explanation. > > I doubt advocates of "emergent properties" will like that either. No, we don't really know enough about the "atoms" of intelligent systems to build one yet. As I said, low-level and high-level properties are complementary and inextricably bound together in highly organized systems, and neglecting either kind will probably result in failure. Your narrow definition of "good science" is slowly falling into disfavor simply because it is no longer considered adequate for fully explaining certain natural phenomena such as quantum events, weather, life, intelligence, etc. Science should still be largely reductionistic, but there are some modern scientific problems that need a more open-minded approach if we ever hope to make any headway with them (scientifically). The experimental method and quantification are not rejected. The essence of science is untouched. Consult the references below if you want to see more scientific support for my position. >----gary---- -- Kevin PS: Thank you for responding with such a well-thought-out article. It forces me to clarify my position not only for you, but for myself as well. One thing: I'm cross-posting this message to comp.ai.philosophy since ours the kind of discussion that really belongs there. If you intend to post a new followup article, would you be so kind as to post it in comp.ai.philosophy only? I'm sure that everyone else in comp.ai would appreciate that. Thanks! Further reading: Bohm, David. _Wholeness and the Implicate Order_. Routledge & Keegan Paul, 1980. David Bohm is a physicist by profession. This work really drives home the holistic nature of quantum mechanics and related disciplines. Hofstadter, Douglas R. _Godel, Escher, Bach_. Basic, 1979. On the pitfalls of singleminded reductionism. Peat, F. David. _Artificial Intelligence: How Machines Think_. Baen, 1985. The final chapter discusses the explications and implications coming out of the modern quest for a specific definition of intelligence.