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Jack
Cohen & Ian Stewart: The
Collapse of Chaos:
discovering
simplicity in a complex world
(Viking: 1994)
“At the heart
of this book lies a paradox. The more we learn about the
universe, the more complicated it appears to be, but we
have discovered that beneath those complexities lie deep
simplicities, laws of nature. How can simple laws explain
complex behavior? Where does the complexity ‘come
from’? ...[As well,] the universe does not always
seem complex. In our daily lives, we experience the world
as a simple place - in fact, we would be unable to function
if we had to grapple with the complexities as such. So,
in order to comprehend our world and humanity’s
place within it, we must do more than just explain higher-level
complexities in terms of lower-level simplicities. We
must explain...where the simplicities
of nature come from. The conventional answer is that deep
down inside, nature is simple: It functions on the basis
of simple laws. Any large-scale simplicities we observe
- such as the spiral form of galaxies, or the tendency
of a flock of geese to string out in a V - are just the
underlying simplicities becoming visible on a higher level.
Unfortunately, this answer is no longer convincing. Chaos
theory tells us that simple laws can have very complicated
- indeed, unpredictable - consequences. Simple laws can
produce complex effects. Complexity theory tells us the
opposite: Complex causes can produce simple effects. And
conventional reductionistic science tells us that inside
the great simplicities of the universe, we find not simplicity
but overwhelming complexity.”
(Cohen & Stewart,
pp.1-2)
The development of science - its techniques, methodologies,
and philosophies - has been a long and complex one, with
no sign of slowing-down to date. Indeed, the rise of approaches
such as chaos and complexity theory in recent times has
further broadened science...albeit at the cost of many
foolish claims that traditional “reductionist”
science is either dead or outmoded - particularly from
ill-informed Humanities scholars, who really ought to
know better. Of the works written by specialists treating
science as a whole - and the proper place of approaches
such as chaos and complexity within it - none to my mind
surpass this, despite the fact that it is over ten years
old, and deals extensively with rapidly-changing areas.
The reason for this is simple. Cohen & Stewart, rather
than attempting the usual breathless outline of cutting-edge
discoveries, arguments (and personalities) beloved of
science journalists, instead offer us something much
more fundamental (and particularly useful to outsiders)...a
tour through the basic hierarchy of explanation alert
to exactly how scientific understanding emerges, precisely
what it entails, and how it is likely to develop in the
future, as it attempts to grasp more and more complex
matters:
“The Collapse
of Chaos shows how simplicity
in nature is generated from chaos and complexity...[in]
interaction. We show that the same simple, large-scale
features occur in many different complex systems, because
patterns of kind do not depend upon detailed substructure.
The book is in two parts. The first half is about what
science knows - and what it doesn’t. The second
half is about how to think
about what science knows - and what it doesn’t.
The first half is a guided tour of the Islands of Truth
that have been mapped by conventional science; the second
half is an adventurous and unorthodox dive into the Oceans
of Ignorance that surround them.... [In this,] we argue
that simplicities of form, function, or behavior emerge
from complexities on lower levels because of the action
of external constraints. The focus moves from things to
rules that govern things.... The final chapter combines
content and context into two new concepts: simplexity
and complicity. Simplexity is the tendency of simple rules
to emerge from underlying disorder and complexity, in
systems whose large-scale structure is independent of
the fine details of their substructure. Complicity is
the tendency of interacting systems to coevolve in a manner
that changes both, leading to a growth of complexity from
simple beginnings - complexity that is unpredictable in
detail, but whose general course is comprehensible and
foreseeable.... If either of us were writing this on his
own, he would be much surer he was right but (paradoxically)
much more cautious in presenting his ideas. Instead, our
joint voice knows that it is probably wrong all over the
place, but puts its ideas forward with immense confidence...[as]
we believe that, even when we’re wrong, we’re
constructively wrong - wrong in a more informative way
than the orthodox story is right.”
(Cohen & Stewart,
pp.1-4)
“Reductionism
seeks to explain all patterns in nature, obvious or
hidden, as simplexities arising from underlying simplicities.
We think that many patterns do not fit this description
at all; they are complicities, arising from internal
complexities and simplicities under the influence of
external complexities and simplicities. Because our
brains themselves evolved through complicity between
their internal representation of reality and the external
reality itself - between their content and their context
- they can recognize features, analogies, and metaphors,
and see patterns in them.”
(Cohen & Stewart,
p.435)
“The reductionist
strategy - take it apart, see what the pieces are, understand
how they fit together - provides simple explanations for
many puzzling complexities. The behavior of atomic nuclei
is explained by the properties and interactions of protons
and neutrons; and we could have told you how these in
turn are explained by the interactions of particles such
as quarks, photons, and gluons operating under more exotic
rules, but we didn’t want to go further in that
direction. The numerology of electron shells explains
the chemistry of elements as expressed in Mendeleev’s
periodic table. Complementary behavior of electron shells,
where an electron ‘missing’ in one atom can
be provided by one that is ‘spare’ in the
other, explain how they combine together to form molecules;
and the Lego-block flexibility of those particular rules
makes it clear that chemistry will be a complex area containing
enormous diversity. The long-chain chemistry of carbon
is a predictable consequence of special features of its
‘self-complementary’ electronic structure
- four pimples and four sockets. The resulting complexity
of organic compounds opens up the way to the organized
complexity of DNA, proteins, and other important biomolecules.
The structure and processes of simpler living things are
determined by their DNA genetics, and its ability to code
for proteins. More complicated life-forms develop through
a sequence of stages, each of which is read out from the
genetic structure in more or less the same way as happens
for simpler organisms; but there is a hierarchical structure
of genes that make proteins, genes that regulate those,
and so on. The origin of life itself, or of complex life
from simple life, is seen to be the inevitable consequence
not just of these processes, but also of their inherent
imperfections. Mistakes in copying can occur; most of
them are disastrous but short-lived, but the occasional
improvement flourishes and reproduces. This selection
mechanism provides the asymmetry that (usually) drives
the evolutionary process toward increasing complexity,
both of organisms and of their development.”
(Cohen & Stewart,
p.179)
As this virtuoso act of summary suggests, Cohen &
Stewart have a genuinely sophisticated understanding of
the value of reductionist approaches - and of the knowledge
these have produced - which makes their critique of exclusively
reductionist thinking both pointed and highly persuasive.
Moreover, they have a way with aphorisms any writer might
envy, as well as what I might venture to call a fundamentally
humanist outlook...perhaps best summarized here, in words
that all intellectuals
would do well to remember.
“Reality may be
a figment of our imagination, as some philosophers argue,
but our imagination is definitely a figment of reality....
[And] romanticism alone can seriously damage your mind,
but reductionism alone can seriously damage your soul.”
(Cohen & Stewart,
p.429-31)
The result is an extremely important book, which shows
no sign at all of dating - even if its key coinages have
not been commonly accepted. Yet, the reasoning behind
them is sound, the writing both clear and entertaining,
and the jokes (opening each chapter) marvellously apposite...with
more wit scattered throughout, particularly at the expense
of the overly reductionistic, but always pointing toward
proper understandings:
“Proponents of
a Theory of Everything effectively believe that when scientists
play Twenty Questions with nature, nature has already
chosen the answer. The job of science is to find the unique
word in nature’s dictionary that fits every conceivable
question we could ask. The actual state of science is
quite different: More often than not we get ourselves
into a conversation something like this:
SCIENTIST: Does it have
three letters?
NATURE: Yes.
SCIENTIST: Is it a color?
NATURE: Yes.
SCIENTIST: Does it begin
with ‘R’?
NATURE: Yes.
SCIENTIST (triumphantly) :
Is it ‘red’?
NATURE: No.
When this kind of thing
happens, scientist first check the questions and answers
again. If everything still holds up, they are forced to
reinterpret some of the questions, or some of the answers.
SCIENTIST: Is it a wave?
NATURE: Yes.
SCIENTIST: Is it a particle?
NATURE: Yes.
SCIENTIST: I think I’d
better go away and invent quantum mechanics.”
(Cohen & Stewart,
p.275)
“A theory is like
a net. It catches what it’s designed to catch....
If you fish nature with the theory of gravity, you catch
elliptical orbits; if you fish with quantum electrodynamics
you catch light and electrons; if you fish with crystallography,
you catch crystals. That’s great, because you can
catch one type of thing without wasting your time on all
the others. But a Theory of Everything is like a Net for
Everything, a net that...would have a mesh so fine that
it catches every atom in the ocean, and every particle
of light. It would be a vast sheet of black plastic....
But if anybody asks you what’s in the net, you have
no idea. It’s black, you can’t see inside,
and even if you could, you can’t pick out anything
interesting.... A Theory of Everything would have the
whole universe wrapped up. And that’s precisely
what would make it useless.”
(Cohen & Stewart,
p.365)
“Science has developed
paradigms for the same reason that mammals developed warm
mothers. That new trick allowed the mammals to throw away
a lot of unnecessary DNA programming [for different temperature
conditions]; paradigms allow science to throw away a lot
of unnecessary facts, by deriving them from general, simple
laws. This is Medawar’s point that ‘theories
destroy facts.’ Within a framework like science,
successive generations of children have to learn
less to know more . The
same is true for successive generations of scientists...[as]
science uses the basic trick of data compression. Replace
a product by a process that generates it. Replace a list
of planetary data by a general law that implies it. Replace
tables of chemical properties by Mendeleev’s periodic
table. Replace measurements made on generations of pea
plants by Mendel’s laws of heredity.... Data compression
is very effective, but there is a price to pay...[as]
the true information-theory cost of data is not just how
many bits it contains, but how difficult the decoding
procedure is.... Scientists often object to the concept
of God, on the grounds that it explains the universe too
easily: You can’t see how it ‘works.’
God is a contextual Theory of Everything. But a reductionist
Theory of Everything suffers from the same problem. The
physicist’s belief that the mathematical laws of
a Theory of Everything really do govern every aspect of
the universe is very like a priest’s belief that
God’s law’s do. The main difference is that
the priest is looking outward while the physicist looks
inward. Both are offering an interpretation of nature;
neither can tell you how it works.”
(Cohen & Stewart,
pp.363-5)
As should be clear by this stage, Cohen & Stewart
are exemplary guides to science - homing in on the most
important questions w/outstanding skill, and treating
them with the clarity (and humour) they (and we) deserve.
As I noted earlier, however, they are more concerned here
with the implications of what we know and how we know
it, than with the specific details of theories and evidence,
lending a philosophical air to the book without, however,
making much use of the specialized language of philosophy.
And, as those familiar with this site should be all-too
aware by now, I always
prefer to source my philosophy from those willing to get
their hands dirty in the relevant areas...
“The universe...looks
like a pretty complicated place if we remove our commonsense
blinkers, and look beneath our comfortable, illusory simplicities.
If we don’t want to be caught napping when that
complexity decides to bite us, we must come to terms with
it. There are two main approaches. Recondite professions
(such as astrology or plumbing) claim to handle these
hidden complexities in their own terms, but shy away from
any attempt to explain their methods. The astrologer who
casts your horoscope and predicts the approach of a tall,
dark stranger, and the plumber who produces an odd-shaped
wrench to unscrew a nut you didn’t even know your
sink possessed, are both keeping a lot up their sleeves.
Science adopts a radically different approach. It claims
to see beyond the apparent complexities to the underlying
simplicities, which it calls laws of nature. By working
with these simple laws, rather than trying to handle the
complexities as complexities, science claims to render
the world once more accessible to common sense. It is
common sense on a much more refined level, common sense
with different intuitions; but when a physicist argues
that perpetual motion machines are impossible because
of the law of conservation of energy, the general line
of thought is just as simple and transparent as the statement
that the cat needs some milk because it’s thirsty.
Common sense, in short, has a lot going for it...when
it is congruent to reality. When it is not, it can go
horribly wrong - like, for example, throwing water onto
a gasoline fire.... The slogan “Water puts out fires”
sounds like common
sense, but it [depends on the context.] ...The trouble
is, our brains mostly think in such slogans. The word
‘comprehend’ originally meant ‘grasp.’
To understand something is to grasp it with your mind,
to make it into an object ,
that you can hold as a unit.... When protohumanity learned
how to generalize about the structure of the natural world,
to classify similar objects under identical labels - in
short, to exploit the power of metaphor - it latched onto
a wonderful trick.... [For,] mental computations must
be in real time, so something quick and dirty is the order
of the day. We have to think in slogans, because a really
high level of congruence with reality takes too long.
So, a flash of black and orange is labelled ‘tiger,’
when it might be just a funny-colored leaf - because tigers
can bite. It’s better to be safe than sorry.”
(Cohen & Stewart,
pp.9-11)
“The universe
appears to simplify at nonhuman scales, because we possess
a very limited set of techniques for converting its behavior
into human-scale effects, in both space and time...[and]
we probably miss a lot of the fun by peering through glasses
darkly. [But] physics takes a pragmatic and severely critical
stance. It concentrates on simple, highly controlled systems;
in return, it expects impeccable agreement between experiment
and theory.... Physicists would argue, quite properly,
that in the absence of evidence that wild electrons behave
differently from tame ones, the onus of proof is on the
skeptic. Physics deals with an invented, simplified world.
That is how it derives its strength, this is why it works
so well: Its raw material is of a type that can be placed
in simple settings. Sciences like biology are less fortunate....
[In such sciences], especially those where really accurate
measurements or repeated experiments aren’t possible,
people nowadays tend to speak of ‘models’
rather than ‘laws.’ They look for underlying
rules and regularities that explain a limited range of
phenomena, in simple, graspable terms. From that point
of view, ‘laws’ may be just spectacularly
successful, very simple, models. The important thing is
that, even though we can’t be certain that what
we think of as laws of nature are actually true, we do
see a lot of patterns and regularities in the world, and
we can use these.”
(Cohen & Stewart,
pp.12-19)
“Reductionism
equips us with a variety of mental funnels, with complexities
at the top, deeper simplicities below.... This structure
of nested funnels provides a chain of logical explanation
that works leads in the reverse direction, ‘upward’
from simple laws to complicated features of the natural
world. The resulting insights tend to be presented in
a deductive form: ‘These
laws imply this
phenomenon, which explains that
observation.’ In contrast, the discovery of the
structure tends to be inductive: ‘This
observation would make sense if that phenomenon
were taking place; and that would make sense if nature
obeyed these
obeyed laws.’ [And] when we look down our reductionist
funnels at the deeper levels of chemistry and physics,
what we find is mathematics: wholistic numerology (electron
shells), geometry (buckyballs), equations (Einstein’s
famous ‘e = mc 2’
relating energy to mass). The logic of reductionism is
most precise in the mathematical depths, and it becomes
progressively more fuzzy as we ascend to the more complex
levels of biology. By the time we reach Darwinian evolution,
the model has become verbal, rather than mathematical.
It is, however, cast in very precise and subtle language,
and much of it is supported by mathematical submodels.
The explanatory logic is still very precise, but its style
has subtly changed. [But] the reductionist strategy seems
far less successful when we think about still higher levels
of organization than evolution...[due to] the sheer complexity
of the system we are trying to reduce.... Interactions
can have a very tiny effect compared to those of individuals,
but if the number of individuals gets big enough, then
it is the interactions that matter most. Unfortunately,
if the effect of any particular interaction is tiny, we
may not be able to work out what it is. We can’t
study it on its own, in a reductionist manner, because
it’s too small; but we can’t study it as part
of the overall system, because we can’t separate
it from all the other interactions. This is one of the
main reasons why we don’t have effective explanations
in ecology, epidemiology, or economics.”
(Cohen & Stewart,
pp.180-2)
By quoting out of context - and similarly venerable techniques
- many in the postmodern Humanities have managed to convince
themselves that scientists such as Cohen & Stewart
are actually supportive of the wooly, jargon-ridden, and
self-satisfied relativism that passes for thinking in
their circles. The reality, thankfully, is considerably
different. Instead of amplifying legitimate concerns about
representation, say, beyond sense - or dismissing them
outright, as many might prefer - they take the hard-nosed
pragmatic line common to most thinking scientists, which
demonstrates exactly
why the relativistic excesses of postmodernism are so
misguided:
“It is undeniable
that the patterns we can make explicit are limited by
the material available to our imaginations. In 1963, Benoit
Mandelbrot introduced the new concept of a ‘fractal,’
a geometric form with [self-similar] fine structure on
all scales of magnification. That concept has since become
a remarkably pervasive influence in scientific thought.
Before 1963, one of the simplicities that pervades the
1990s picture of the world was - missing. Just as the
concept ‘sphere’ unites raindrops, planets
and suns, so now we perceive a unity between such diverse
objects as trees, clouds, and coastlines. They are irregular,
but with the same kind of irregularities. Before the simplicity
‘fractal’ was introduced, it was not only
impossible to express this unity, it was pretty much impossible
to notice it. This same example, however, does make us
ask whether our mental patterns are genuine reflections
of reality.... [Nevertheless,] forms are the result of
processes, and congruences of processes are metaphors
with genuinely useful content.... In recent years, a fecund
mathematics has generated innumerable ‘new’
mental images, such as catastrophes, chaos, fractals,
that might be advance warning of new simplicities in the
world. Each extends the list of patterns that we can name,
recognize, and manipulate. [But] it is not clear that
all such patterns must necessarily prove operationally
congruent to reality...[for] the universe that we experience
is in a very real sense a figment of our imagination.
However, this does not in any way imply that the universe
itself has no independent existence...[since] our brains
are ‘figments of reality’...[which] have survived
millions of years of natural selection for congruence
with reality. [And,] what better way to build simplified
models of the world than to exploit simplicities that
are actually there?”
(Cohen & Stewart,
pp.23-7)
Another major strength of this work lies in its accessible
approach to key aspects of scientific thinking - such
as the rise of chaos theory and mathematical/computer
modelling - treating not only their foundations, but also
offering readers an informed understanding of their strengths...and
weaknesses. And in a world increasingly dominated by opaque
expertise, such understandings are crucially important.
“The common feature
of...unpredictable yet deterministic systems is the process
‘stretch and fold.’ If the dynamics kneads
the system like a lump of dough, stretching it out and
folding it back on itself, then states that are close
together always get pulled apart. On the other hand, states
that are far apart may suddenly be folded together. The
system can’t settle down to anything simple, because
simple structures get pulled to bits, but it can’t
escape altogether, because it’s perpetually folded
back into the same space. Like a ball in a pinball machine,
it is pushed away from all the pins - the simple types
of behavior - but it can’t escape from the table.
What do you do if you’re not allowed to behave simply,
but you can’t get away? You are forced to do something
complicated. The pinball bounces from pin to pin, never
doing the same thing twice. This kind of complicated behavior,
produced by simple, deterministic rules, is called chaos.
Before computers became powerful enough, hardly anybody
noticed it could occur; whenever they ran into it, the
problem got too hard, so they gave up. They didn’t
ask why it had gotten too hard; they just went off and
worked on a different problem. Now that our computers
are up to the task, the dreadful truth has become inescapable:
Chaos is everywhere. It is just as common as the nice,
simple behavior so valued by traditional physics.”
(Cohen & Stewart,
p.190)
“Mathematics wallows
in emergent phenomena. It also came to terms, long ago,
with something that often puzzles nonmathematicians. By
definition, all mathematical statements are tautologies.
Their conclusions are logical consequences of their hypotheses.
The hypotheses already ‘contain’ the information
in the conclusions. The conclusions add nothing to what
was implicitly known already. Mathematics tells you nothing
new. Except, of course, that it makes things explicit
rather than implicit.... [But] it’s not enough for
something to be true; you have to know it’s true,
and be able to explain why. Otherwise, you don’t
know whether it’s safe to use it. [And,] far from
being unimportant or tautologous, higher-level simplicities
are the bread and butter of science - the simple, recognizable
features of otherwise complicated theories that we use
to understand the natural world. The representation of
a higher-level simplicity as an explicit consequence of
lower-level complexities tells us interesting things about
the connection between the levels. But often it adds no
useful gadgets to a working scientist’s tool kit,
because a high-level simplicity is much easier to think
about than some chain of consequences that causes it.
When you use a hammer, you don’t want to worry about
its molecular structure. Mathematicians know this well.
‘A theorem,’ said Christopher Zeeman, ‘is
an intellectual resting point’ - something you can
stand on to proceed further. Something you can know ,
can encapsulate, grasp as a whole. Key scientific concepts
have this same quality.”
(Cohen & Stewart,
pp.234-5)
“Higher levels
of the reductionist story use mathematics as a metaphor,
not as a precise representation of nature.... [Yet] even
though mathematical models do not correspond to the whole
of reality - indeed, because
they do not correspond to the whole of reality - they
offer definite advantages. Because mathematics is more
precise than words, it can handle more delicate distinctions.
It can also direct attention to features that are not
directly observable, such as average infection rates.
And it can be used in thought experiments to show that
many of our cherished beliefs - such as that in the impossibility
of systems spontaneously becoming more complex - are false.
Mathematical models have a disadvantage, too - a trap
that has caught more than one top scientist.... The quality
of a mathematical conclusion is determined by a lot more
than just the accuracy of the calculations. There are
three main types of mistake. Errors made within the model
are the easy
type to spot. Harder are errors made in the explicit assumptions
that lie behind the model. The hardest of all to spot
are the implicit assumptions in the worldview that suggested
the model.... Impeccable mathematics can produce nonsense,
if it is based on nonsensical assumptions. ‘Garbage
in, garbage out,’ as the computer scientists say.
You might expect a book by a mathematician and a biologist
to praise the precision of mathematics as a tool for digging
out surprising biological truths. On the contrary, we
both warn you not to take mathematical models too seriously.
Surprising consequences are fine, but consequences so
surprising that they don’t make any sense are almost
certainly based on false assumptions. Don’t be impressed
by mathematics just because you can’t understand
it.”
(Cohen & Stewart,
pp.184-6)
“Over the centuries,
scientists have devised a working philosophy that places
the emphasis upon simplicity. The principle known as Occam’s
razor asserts that assumptions should not be made unnecessarily
complicated.... So, when scientists select theories, they
do not use just the criterion of agreement or disagreement
with observations. They also have aesthetic principles
in mind. They want the theory to be universal, not peculiar
to some particular place and time. They want it to be
elegant, not held together with chewing gum and string.
They use these aesthetic principles to remove cloud of
‘trivially’ competing theories that necessarily
surrounds every theory. Paul Dirac took a rather extreme
view, saying that he would prefer a false but beautiful
theory to a correct but ugly one. [But] Occam’s
razor isn’t a scientific theory; it’s a philosophical
principle, a meta-theory, a theory about theories. And
it has its problems. At any given instant in the development
of science, Occam’s razor is great for chopping
away unnecessary detail, and concentrating your mind on
what currently seems to matter. However, as science develops,
theories that started simple tend to get more complicated...[and]
over time, we [also] revise our views of what is or is
not simple.... The story of science is that of repeated
revolutions in our conception of the simple.”
(Cohen & Stewart,
pp.225-8)
Ian Stewart is a mathematician....who lends this work’s
treatment of mathematics his flair and deep insight. On
the other hand, Jack Cohen is a developmental biologist
- a very different realm one, would think , although it
is the coming together of their thoughts in unexpected
consilience that has delivered the key insights of this
book. However, the most important sections of the work
are, arguably, those centred around developmental questions...since
these show most clearly how necessary pluralist perspectives
are, and how essential it is to consider context:
“Evolution mostly
leads to increased complexity in individual organisms.
Complexity is downhill to evolution.... There are two
rather difficult ideas to be grasped. The first is that
it is ‘easier’ to add stages onto an already
effective sequence, than it is to modify earlier steps
in the sequence. So, most innovations that offer a competitive
edge are refinements that complicate (and often enlarge)
the adult stage
of organisms. The second idea concerns the kind of innovation:
It is more likely that competitive advantage will be gained
by adding something than by removing it. Neither idea
is universally valid, but both are true far more often
than they are false.... The reason [for the first] is
quite simple. When you add a new stage, you can build
on what already exists.... Don’t forget, we’re
talking of modifying a process here, not just changing
the product...[and] if you tinker with an early stage,
you may well mess up everything that happens afterwards....
The second idea is that improvements generally involve
extra gadgetry rather than less. This is not a rigid rule
either, but again it makes a lot of sense. Suppose you
decide to remove something. It was presumably there for
a reason, so you’ll lose whatever advantage it originally
conveyed. The advantage you gain by simplification either
has to be so good that you don’t mind, or (more
likely) the thing you’ve removed has already become
obsolete. Both of these methods for improvement are uncommon
- though striking when they work.”
(Cohen & Stewart,
pp.135-7)
“Even in an isolated
ecology with limited raw materials, evolutionary pressures
lead to diversity and the occupation of ever more specialized
niches. But this process of continuing complication can’t
go on forever. Living creatures are forced by evolutionary
pressure to operate right at the limits of what they are
capable of...[and] there may come a time when the ‘style’
of an organism - its system of organization - starts to
get top-heavy. Having chosen to specialize, all it can
then do to improve is to become more specialized; it’s
trapped in an evolutionary dead end.... In such circumstances,
it is evolutionarily worthwhile for some of the competitors
to cut out the later, complicated part of their life history;
this excision results in neoteny (omitting the adult stage)
or progenesis (breeding as a larva), depending on whether
stability or exploitation is the background rhythm. If
it is advantageous to stay the same, to continue to occupy
a well-developed and canalized niche, then you get neoteny;
if there is a new niche to be developed out of the old
one and exploited to the full, the result is progenesis....
From this new basis, a new set of competing complications
can be established. Advance, retreat-and-consolidate,
advance again.”
(Cohen & Stewart,
pp.140-1)
“The standard
textbook story is of a random mutation in the DNA providing
a range of developmental variants (many of which are lethal:
The developmental system crashes). However, a single-gene
mutation rarely has a predictable effect upon the development
of an organism. Waddington showed this clearly: The extent
to which development is affected by either an environmental
kick or a gene difference depends upon what other genes
are present...[and] when the mutation first happens there
is always a normal
version available on the equivalent chromosome from the
other parent.... More subtly, in canalized development,
where the entire system has stabilized itself against
environmental and genetic changes, there are all kinds
of alternative routes to each stage or function, often
because the original gene sequence has been duplicated,
or indeed multiplied.... [Moreover,] there is an even
more subtle reason why most DNA changes (and most environmental
differences) don’t affect the developmental program
in any obvious way. This is because the systems concerned
are versatile. Like the subprogram for skin, which permits
any size of embryo to grow within it without bursting,
most of the developmental programs of most animals and
plants have lots of if-then contingency plans.... Such
built-in versatility, in which the ends are predictable
but the means can be varied, is characteristic of life.”
(Cohen & Stewart,
pp.141-3)
“At the end of
chapter 3, we likened the developing egg to a new computer
that is provided with a start-up disc by Mother. We must
now take a more contextual view, and amend that image....
Mother provides the ‘hardware,’ the cell that
begins to develop; the new item is the software, the DNA
inside the egg (provided by combining sequences from both
father and mother and peculiar to the developing infant).
That is, Mother provides the whole computer, not the start-up
disk. Indeed, there is no start-up disk: The computer
is up and running before the infant’s DNA software
is inserted into it, and only then does it begin to obey
the program on the infant DNA. Notice how different
the roles of infant DNA (content) and mother (context)
now become. In the reductionist image of chapter 3, all
of the magic is in the infant DNA...[and] the maternal
context is just a starter motor to get the process going.
But in our new image, all of the magic lies in the maternal
context, the fully functioning egg into which a naive
nucleus containing infant DNA is inserted and run. [And]
it is because the context is at least as important as
the content that we can envisage a case in which the same
DNA message has vastly different developmental meanings....
To twist one of [Richard] Dawkins’s own images to
our own purposes: The Blind Watchmaker is indeed blind,
so it can’t read its own blueprints. Biological
development is a complicated transaction between the DNA
‘program’ and its host organism; neither alone
can construct a creature, and neither alone holds all
the secrets, not even implicitly.”
(Cohen & Stewart,
pp.298-306)
Another key aspect of The
Collapse of Chaos is Cohen & Stewart’s
insightful critique of extensions of Information Theory
- and other decontextualized approaches - into the realms
of meaning. And, as usual, their analysis (and use of
examples) make clear just what a ridiculous stretch this
is...and how grossly inappropriate such models are for
dealing with anything we would consider complex enough
to be called a “message”.
“The standard
quantitative measure of information - the number of characters
in the message - is well designed for its original purpose,
that of informing the engineer who is required to build
devices to transmit and receive the message. Those devices
don’t care what the message means. Meaning is a
quality, not a quantity, and it is highly dependent upon
context.”
(Cohen & Stewart,
p.289)
“The meaning in
a language does not reside in the code, the words, the
grammar, the symbols. It stems from the shared interpretation
of those symbols in the mind of sender and receiver. This
in turn stems from the existence of a shared context.
For language, the context is the culture shared by those
who speak the language. For the DNA message, the context
is biological development [and] if the manner by which
DNA code is transformed into creatures is ignored, we
have no idea whatever of the possible complexity of the
creature that results from a given segment of DNA....
[Therefore,] prescription is closer to the mark than description,
not just for DNA but for any message outside the abstract
setting of information theory, which deliberately strips
away context. A prescription from the doctor is not a
cure in itself; it only becomes one when taken to a drugstore,
received by a pharmacist, and acted upon. All messages
in the real world that really are messages happen within
a context. That context may be evolutionary, chemical,
biological, neurological, linguistic, or technological,
but it transforms the question of information content
beyond measure. We understand this point for technology.
We don’t usually try to play a compact disc on a
telephone answering-machine. But when thinking about the
natural world, we often forget that we don’t
know how much contextual input there is into processes
we like to model as ‘message sending.’”
(Cohen & Stewart,
pp.354-5)
There is much of great merit in this book which I do not
have space to consider here: on the proper care and housing
of Schrodinger’s cat, why the entropy of the universe
cannot be increasing, and perhaps the best short treatment
of Gaia theory I have yet to encounter.
However, as the authors’ note in their introduction,
the most original portions of the book treat that which
they refer to as simplexity and complicity....the latter,
in particular, suggesting how future science may come
to treat areas mainly seen now as intractably complex.
And, whilst these coinages have not been adopted to date,
I suspect the ideas behind them have been taken very seriously.
Because they make compelling sense re questions which
science has only just begun to ask...
“Emergent simplicities
are the peaks in the landscapes of the possible...[and]
the ‘big questions’ in science are about the
big peaks. Reductionism tries to understand them by digging
deep down inside the peak, to see what lies beneath it,
what it’s built upon. But mountain peaks aren’t
built by piling up long thin tubes of rock; they come
from the overall folding of the total landscape...[and]
nature’s geography is not the geography of laws,
but of the landscape that emerges from those laws. We
also need a description that makes sense on the level
of the landscape itself.”
(Cohen & Stewart,
p.395)
“We shall give
the name ‘simplexity’ to the process whereby
a system of rules can engender simple features. Simplexity
is the emergence of large-scale simplicities as a direct
consequence of rules. Newton’s laws - rules - of
motion have direct mathematical implications about centers
of mass, energy conservation, and so on. You can write
them down in a few pages, grasp them in their entirety....
An important point about simplexities is that their
presence is guaranteed, once you have the rules. Any system
with the same rules will necessarily exhibit exactly the
same simplexities.... Simplexity is, appropriately, a
relatively simple concept. It is the easy way for different
rules to generate similar or even identical features;
it works because the rules themselves are very similar.
Now we consider something much more subtle, in which totally
different rules converge to produce similar features,
and so exhibit the same large-scale structural patterns.
We call it complicity. For example, let’s think
about the transmission of malaria.... What is special
about this kind of system is that the interaction of several
subsystems enlarges the space of the possible .
There’s nothing remotely like malaria in any of
the component spaces on their own...but when those spaces
interact, they open up entirely new possibilities....
Simplexity merely explores a fixed state of the possible.
Complicity enlarges it. And both processes collapse the
underlying chaos, producing stable features from a sea
of complexity and randomness. [But] complicity, by its
nature, is so intricate and convoluted that any attempt
to dissect out its internal workings and past history
just leads to the Reductionist Nightmare. Despite this,
there are patterns to complicity - patterns that let us
recognize its presence. They are meta-rules, large-scale
universals. You couldn’t have predicted malaria,
in all its gory detail, from the interaction of blood
space and bloodsucker space. But with a bit of imagination,
you could have predicted the universal pattern ‘parasite’
and guessed that the combined space [bloodsuckers, flight,
multiple hosts] opened up new niches for parasitism.”
(Cohen & Stewart,
pp.411-15)
“These meta-rules
and meta-meta-rules work on the level of features, and
only on that level. Their explanations do not lie inside
the complexities of the component subsystems, which rapidly
diverge as you progress to deeper reductionist levels.
The meta-rules are emergent, not reductionist. Indeed,
they are so nonreductionist that it doesn’t even
matter whether a given feature arose through simplexity
or complicity. As long as it looks the same to the outside
world, that’s all that matters. This fungibility
or universality is what makes the patterns universal,
and it’s what lets them collapse chaos.... Complicity
arises when simple systems interact in a way that changes
both, and erases their dependence on initial conditions.
The hallmark of complicity is the occurrence of the very
same feature or features, in systems whose rules are either
known to be very different, or are expected to be very
different if only we could find out what they are. This
carries an important consequence: Complicity is a convergent
process; it homes in on the same features regardless of
the fine detail in the rules. Another way to say this
is that complicity leads to ‘replaceability’
of (some) components.... [Moreover,] because complicity,
by its nature, is convergent...it cannot be reduced to
a particular system of rules in any useful manner....
We can nevertheless explain roughly how it works, by appealing
to the idea of spaces of the possible. Continuing to focus
on the DNA/organism example...there is a feedback loop
between the two spaces, which cause them to coevolve toward
a common dynamic.... [And] because the two spaces have
very different geography, their individual attractors
don’t match up nicely, so the feedback between the
spaces has a creative effect...[generating] a new, combined
geography that in no sensible way can be thought of as
a mixture of the two separate geographies.”
(Cohen & Stewart,
pp.415-21)
Cohen and Stewart’s key example of complicity is
evolution - the crucial subsystems being the chemistry
of DNA and the systematic ways organisms interact with
their environments - and the plethora of examples of convergent
evolution provide a most compelling argument for the concept.
As such, it is perhaps not so surprising that evolution
is so widely misunderstood - even by many scientists -
for proper understanding requires us to stretch our minds
in several deeply unfamiliar ways...
“Few of our daily
experiences equip us to think sensibly about evolutionary
systems. We tend to act on simplified models of the world;
we seldom think about the effects of small changes over
huge periods of time; and we almost never try to tackle
anything remotely as complex as the totality of life on
earth. Many aspects of evolution run counter to our intuition.”
(Cohen & Stewart,
p.98)
Jack Cohen & Ian Stewart’s The
Collapse of Chaos is far more than an introduction
to chaos and complexity theory...or, indeed, than a grand
tour of the hierarchies of understandings which structure
conventional science. It is all of those things, as well
as a modest proposal to expand the nature of science to
properly incorporate contextual factors, an insightful
(and moderate, read: useful) critique of excessively reductionist
approaches to complex areas, a meditation on the nature
of natural laws, and a highly readable and entertaining
book to boot.
This does not mean - of course! - that it is flawless...in
particular, I found chapter eleven’s promotion of
the Aquatic Ape and Meme theories to be markedly weak...and
the latter even going against the contextual thrust of
the work (when properly understood). Nevertheless, this
is a work with unique virtues, that more than amply outweigh
its few faults. And, as an introduction to scientific
thinking/understanding - both mainstream and emergent
- it has not be bettered. Read it, and see...
“We began by asking
if the universe is simple or complicated. The answer:
It depends on the context you have in mind when asking
the question, and the kind of answer you want.... Nothing
is as simple - or as complex - as we thought when we began.
Simple rules can breed simple behavior or complex; complex
rules can breed simple behavior, or complex. Contrary
to common belief, complexity is one of the least conserved
quantities in the universe. So are those things that go
with it, such as information, meaning, organization, awareness.
You can sometimes get something for nothing - or nothing
for something.... We think the key is to understand complicity,
not as an incredibly complex reductionist network, but
as the interaction of features within different spaces
of the possible. That is, we must put the dynamics
back into biological development, evolution, and brain
function, with the emphasis being on qualitative forms
and features. Think of DNA and organisms. We’ve
already argued that the organism does not ‘see’
the DNA code, but only those features of it that produce
particular effects that matter to the organism. Similarly,
DNA does not ‘see’ organisms; all that matters
to DNA is that the organism bearing it should survive
to replicate it. This is the ‘selfish gene’
image, but as one aspect of a double-edged process, not
as the sole factor. Each system reacts only to the features
of the other. So what we need is a theory of features,
an understanding of how the geographies of spaces of the
possible conspire to create new patterns, and combined
dynamics.... We’re not saying that the reductionist
approach should be abandoned, and we’re certainly
not advocating replacing it by Just So Stories. But we
think that too much of the emphasis currently placed on
reductionism stems from the Panda Principle: It was there
first, and its devotees won’t let anything else
displace it. And we think that a lot more effort should
be put into questions such as meaning, structure, and
development, so that science can combine internals and
externals into a single, coherent scheme.”
(Cohen & Stewart,
pp.441-3)
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