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Paul Davies: emergentist vs. reductionist
By Mark Perakh
Posted September 25, 2004
Discussion
This essay is a commentary to the introductory chapter by
renowned British physicist and philosopher Paul Davies in the collection From
Complexity to Life edited by Niels Henrik Gregersen. [1] It is a part of a planned series of essays
which will review the entire collection in question. Since this commentary is
about the introductory chapter, it should have preceded reviews of other
chapters in the collection. However, for reasons explained in my review of
Charles Bennet's chapter [2] that review was posted earlier. From now on reviews of various chapters in
the collection will appear in the order they appear in Gregersen's collection.
Davies's
introductory chapter is titled Toward an Emergentist Worldview. This
title seems to be slightly misleading as it can create the impression that
Davies's intention was to show how the trends in philosophical foundation of
modern science lead to the dominance of the emergentist interpretation of natural
phenomena. Recall that the term "emergentist" relates to the opinion that is
contrary to "reductionist" view, the latter succinctly expressed as the notion
that the whole is just the sum of its constituents. The emergentist view maintains that there is a qualitative
difference between the whole and the sum of its components. In the reductionist
view, having explained the behavior of components entails also the explanation
of the behavior of the whole: "everything that happens in the physical world is
ultimately just the rearrangement of atoms" (page 4 in Davies's chapter). On
the other hand, the emergentist view holds that at every level of increasing
complexity a new quality emerges which is not reducible to simply the sum of
the behaviors of the entities at the lower rung of complexity.
It is
interesting to note that the "emergentist" view was in fact adopted by the reigning
"Marxist philosophy" in the former USSR, despite that philosophy being
materialistic and atheistic. This may come as a surprise to the proponents of
the emergentist side in the today's dispute who often tend to associate the
reductionist view with atheism. The concept of Dialectical Materialism in
its Soviet interpretation, as it was hammered into the brains of the Soviet
citizens who were constantly forced to study Marxism-Leninism, entailed the
notion that there exist several types of "motion" hierarchically structured, so
a higher level is not reducible to the lower level. For example, chemical
"motion" is not reducible to mechanical "motion," biological "motion" is not
reducible to chemical, social "motion" is not reducible to biological, etc. This view was based in Hegel's concept
(borrowed by Marx and Engels) of the "transformation of quantity into
quality." Whenever this concept seemed
to contradict the materialistic basis of Marx-Engels's philosophical system, the
"experts" in Marxism-Leninism were adept at explaining away any seeming
contradictions in the officially approved views, mainly using notions stemming
from Hegel's dialectics.
The fact is,
though, that the title of Davies's introduction does not really reflect the
contents of the book. In fact, none of
the contributors seems to defend a
strictly reductionist view, so from the standpoint of the authors it is not
about the road "toward" the emergentist view as this road seems to have been
already traveled and all the contributors adhere, to this or that extent, to
the emergentist view.
Davies
proceeds to discuss the "chaos vs complexity" dichotomy, definitions of
complexity, and links between evolution and information. He discusses briefly
the chapters in the same collection by other contributors, such as Gregory
Chaitin and Charles Bennett, or Stuart Kauffman and William Dembski.
To my mind,
Davies's consideration of works by Chaitin and Bennett in one breath is not
fully justified. There seems to be a substantial difference between the levels
of Chaitin's classical, elegant and rigorous mathematical theory of complexity
and Bennett's less rigorous effort to classify various types of complexity. (Bennett's
chapter is discussed in detail at this site [2].) Much more
disappointing is Davies's juxtaposition of chapters by Kauffman and Dembski
(page 8). To my mind, there is an unbridgeable gap between Dembski's and
Kaufmann's chapters. Kauffman's chapter, although some of its points may seem
controversial, nevertheless offers interesting, original, and intriguing
notions. (I plan to discuss this chapter in detail in a separate post.) On the
other hand, Dembski's chapter, as could be expected by anybody familiar with
the literary output of this prolific propagandist of Intelligent Design, is
just a repetition of mantras about Specified Complexity, the No Free Lunch
theorems allegedly prohibiting Darwinian evolution, and other equally unfounded
asseverations familiar from Dembski's earlier publications. It is sad that not
only was the editor of this collection, philosopher Niels Henrik Gregersen,
evidently impressed by Dembski's seeming sophistication to include his opus in
the collection, but also that such a well qualified physicist-philosopher as
Paul Davies is willing to seriously discuss Dembski's chapter along with that
of Kauffman.
In my
opinion, Dembski literary production does not deserve a detailed response
except that his name crops up here and there so frequently that it attracts
attention much exceeding the significance of his discourse and therefore
compels some scientists and philosophers to rebut his assertions. I have criticized
Dembski's production at length elsewhere [3] and will not repeat it
here.
One more
section of Davies's article is titled "Linking Evolution and Information." To
my mind, some aspects of this section are disappointing. For example, on page 7 we read, "Information
also crops up in thermodynamics as the negative entropy." This is a nebulous statement by no means
commonly accepted either in thermodynamics or in information theory. (In
particular, this notion is disputed in the article by Ian Stewart in the same
collection, which I will discuss separately).
The notion that entropy is the negative of information has indeed been
proposed more than once, but it has also invoked counter-arguments. Let us
imagine that we have two entities, A and B. Assume that A is sending a text to
B (this text may be either a meaningful message or gibberish, the difference
inconsequential within the framework of classical information theory which does
not distinguish between meaningful messages and gibberish). As a result of the
text's transmission from A to B, the receiver B acquires a certain amount of
information. However, nothing happens to the sender A – it still holds the same
amount of information as before. Unlike energy, information is not conserved,
it can be sent without decreasing its amount in the source.
And what
about entropy? In the sense of
classical information theory, entropy is just the average information. [4]
Entropy can be used to measure the amount of information in the message, being
in fact the measure of the text's disorder. It has no intrinsic sense –
assigning to it minus or plus is arbitrary as it can equally measure the growth
and the decrease of information. Therefore, while the increase of entropy can
in certain cases be interpreted as measuring decrease of information, it is by
no means the general definition of entropy vs. information relationship,
because in some other cases it can equally be interpreted in the opposite way –
an increase of information measured by the increase of entropy.
To my mind,
disappointing also is the section titled "Fine-tuning and Complexity." While Davies reasonably states that simply
saying "'God made it this way' is unlikely to satisfy a skeptical scientist,"
(page 11), he proceeds to assert that such a skepticism "introduces a
contradiction into the very foundation of science. The essence of the
scientist's belief system is that nature is neither arbitrary nor absurd –
there are valid reasons for the ways things are."
This
assertion seems to me to be doubtful on several accounts. First, the skeptical
attitude to the assertion that "God made it that way" by no means translates
into the denial of the valid reasons for the things being what they are. A
universe without God is not necessarily a universe that is absurd and that has
no valid reasons to be what it is. These valid reasons may well reside within
nature and require no hypothesis about a supernatural source of their validity.
Second, the
principle that the universe is not absurd is not known in science. While
science is based on the assumption that the clock of the universe ticks
following a certain system of laws, it does not necessarily entail the notion
that all those laws are not arbitrary on some sufficiently deep level. The
answer to that question is not known and the question itself belongs in philosophy;
different scientists may adhere to different philosophies, including one
assuming arbitrariness of the most fundamental "first level" laws, while many
scientists have no interest in this question and hence no philosophical
preferences at all.
Continuing,
Davies discusses two competing views – one suggesting that the "fine-tuning" of
physical constants in a way favoring the existence of life points to the hand
of designing intelligence, and the other based on a hypothesis about multiple
universes among which ours is just the lucky one with the proper set of laws
and values of constants. In Davies's view, from the standpoint of Occam's
razor, both views are equivalent. To my mind, such a position does not seem to
be substantiated. Multiple universes are products of speculation, but they are
just different versions of our universe which definitely exists and whose many
properties we know for fact. On the other hand, the supernatural agent
responsible for the laws of physics and the values of the constants is a
product of sheer imagination as there is not a single observed fact pointing to
the existence of such an agent besides ancient legends which, moreover, exist
in numerous mutually contradicting versions. Therefore, from the standpoint of
Occam's razor (to which Davies refers in his assertion), the assumption of
multiple universes, although hypothetical, is more parsimonious than the
hypothesis of a supernatural entity.
Davies's
introductory chapter concludes with a section titled "Complexity Studies and
the Quest for Meaning." To my mind this
section is solidly substantiated as largely uncontroversial. One interesting
point in this section is Davies's assertion that "the wide majority of modern
theologians find the intelligent design proposal unattractive" (page 15)
because "it seems to commit the fallacy of misplaced concreteness. God becomes
too closely tied up with (assumed) gaps in scientific explanations." Until now, the explicit critique of
intelligent design was coming largely from scientists with the expertise in
information theory, probability theory, mathematical statistics, etc. Although
some of them pointed out that arguments of ID advocates often boil down to
"god-of-the-gaps" concept, the main thrust of that critique was aimed at specific
faults of intelligent design ideas from the standpoint of the listed fields of
science. While rejecting intelligent design, in particular for being
unscientific, these expert critics seemed to be willing to leave open a
possibility that the ID concepts might be legitimately discussed within a
theological framework. If, though, as
Davies writes, most theologians are unhappy with intelligent design, then its prospects
look even gloomier portending its inglorious collapse as an attempt to pose a
serious challenge to genuine science.
I plan to
offer a commentary to Davies's other article in this collection separately.
References
[1] Niels Henrik Gregersen, editor. From Complexity to
Life: On the Emergence of Life and Meaning. NY: Oxford University Press,
2003.
[2] Mark Perakh. "Defining Complexity." On TalkReason, www.talkreason.org/articles/complexity.pdf,
posted August 12, 2004.
[3] Mark Perakh, Unintelligent Design. Amherst, NY:
Prometheus Books, 2004.
[S]See also Perakh's posts in the Critique of Intelligent Design section on this site.
[4] Claude E. Shannon, "A Mathematical Theory of
Communication". Parts 1 and 2, Bell System Technology Journal, July 1948,
379-390; October 1948, 623-637.
Discussion
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