----- Original Message -----
Sent: Tuesday, January 25, 2005 6:11
PM
Subject: Re: Rosen cf. Kauffman
Hi Howard,
An interesting post. I have some comments and a few questions and
corrections, as well...
I must emphasize that any critical comments are only my academic
opinion and do not in any way detract from my close personal friendship and
high regard for them both.
Thanks for that-- it does make a difference.
Rosen began studying wet biology in high school,
What is "wet biology"?
He had been doing experimental biology for almost a decade by the
time he was in high school! It was really that he realized he would never get
the answers to his questions about life that made him begin to look more at
theoretical science. Math was a tool he thought might be very useful, so he
pursued it almost exclusively right until he got to Chicago. He hadn't
expected to find a venue for doing the kind of biology he intended to do until
he got out of school. So Rashevsky's fairly recent epiphany, just before my
father got there, was providential.
but his instincts and abilities were for mathematics rather than
experimental biology. After studying math and physics, it was largely because
of the influence of Rashevsky's relational models that he finally found that
his deepest interest was in how our epistemology and our assumptions about
scientific models influence our concept of life. As members of this list know,
his basic conclusion, developed as an analogy with the creative open-ended
"corpus of mathematics," was that (as in mathematics) formal (computable,
purely syntactic) models are too "impoverished" to capture the creative
open-ended novelties of life.
Rashevsky had only begun to feel his way towards a new way to do
biology when my father met him. He was on the right track, though and he
offered my father the freedom to do things his own way. Which of them
influenced the other more, is a matter of debate. I tend to think that this
brilliant kid with a brainful of new ideas was exactly what Rashevsky needed
to help him crystallize his own sense that reductionism was missing something
essential. My mother tells a story of the night before Dad's defense of
thesis, when Rashevsky called up in a panic and Dad had to spend a couple
hours "talking him down"... When he got off the phone, he turned to her and
said, "I can't believe it! He still doesn't get it, even after all this time!"
In Robert Rosen's published work, however, Rashevsky always was treated with
extreme deference because he was, in essence, the only father figure my father
really had. He was protective of Rashevsky and respected Rashevsky's
intelligence, courage, and stubbornness. I think Dad genuinely loved
Rashevsky, the way a son loves a father. That comes through in everything he
wrote about Rashevsky's character and career.
Kauffman criticizes Rosen (as have I and others) for his imposing claims
written in a language that few biologists understand, and that have as yet
suggested no biological observables that could allow a verifiable model.
This is a legitimate criticism, at least about the language part.
He said he wrote as if he were speaking to himself. I've said before that I
don't think that's entirely true; it's more accurate to say that he was
speaking at a level that he was comfortable with but he knew full well that
the vast majority of the rest of humanity would not be able to "keep up". I
tend to think it was his form of "code" such that, in order for any
readers to use the knowledge he had accumulated over a lifetime, they had
to do some work, too. But as I've mentioned, a significant part of "cracking
the code" is simply to realize that all of the mathematics are there
in the form of illustrations of the main ideas. Proofs. You can read only
the prose and still get the full concepts. He was the first to say that
mathematics is not everything and where biology is concerned, it's a useful
tool-- as long as we don't forget it's a tool.
Regarding the second part of that... how do you conclude that he
suggested no biological observables that could allow a verifiable model? In my
experience, his books are peppered with examples-- all of which are
verifiable. A great many are self-evident, it seems to me.
Kauffman, on the other hand, has a simple computer simulation that
behaves by various interpretations like developing organisms and like an
evolving population. If I had to say it in < 20 words, Kauffman has
empirical models without a specific epistemology; Rosen has an epistemology
without (as yet) specific empirical models.
How would Stephen Wolfram's computer simulations compare with
Kauffman's?
Judith
----- Original Message -----
Sent: Tuesday, January 25, 2005 1:23
AM
Subject: [ROSEN] Rosen cf.
Kauffman
At 11:23 AM 1/24/05 +0200, Ayten
wrote:
[snip]
>After having written these passages, I asked myself
the question of how
>close Kauffmann and Rosen in their views on this
question of What is Life? I
>also further asked myself if the main
actors of this list as Tim, John K,
>and Judith consider making a
comparison of these two minds and show for us
>similarities and
dissimilarities . . .
HP: Here are some of my own
comparisons between the minds of Rosen and
Stuart Kauffman. I have known
them both personally and professionally for
many years. But first, since
in the past Tim and Judith have misinterpreted
some of my critical
opinions as a personal attack, I must emphasize that
any critical
comments are only my academic opinion and do not in any way
detract from
my close personal friendship and high regard for them both.
John M's
intuition is correct. Here are two different types of scientific
minds
that start from different backgrounds and work from divergent points
of
view, ending up with completely different types of models. Kauffman
began as an MD but was attracted to experimental developmental biology.
Then, largely because of a single computer program, and with no
significant
mathematical background, he morphed into a theoretical
biologist focusing
on self-organization, origin of life, non-Darwinian
evolution, and
development.
Rosen began studying wet biology in
high school, but his instincts and
abilities were for mathematics rather
than experimental biology. After
studying math and physics, it was
largely because of the influence of
Rashevsky's relational models that
he finally found that his deepest
interest was in how our epistemology
and our assumptions about scientific
models influence our concept of
life. As members of this list know, his
basic conclusion, developed as
an analogy with the creative open-ended
"corpus of mathematics," was
that (as in mathematics) formal (computable,
purely syntactic) models
are too "impoverished" to capture the creative
open-ended novelties of
life.
Kauffman's basic computer program (an elaboration of previous
work by Ashby
and Walker in England) is remarkable for three things, its
simplicity, its
initial randomness, and the richness of the
interpretations he gives its
results. Kauffman originally discovered
these computed results entirely
empirically and largely unexpectedly.
The basic model is a randomly
connected network of random (boolean
function) nodes started with random
initial conditions -- i.e., maximum
disorder. The discrete states of the
network are just the current values
of the nodes, and the next state is
completely deterministic (unless
externally mutated). The well-known (and
now mathematically understood)
result for low connectivity is that the
paths in the exponentially
enormous state-space follow transient paths
collapsing into relatively
few, short, stable limit cycles. Higher
connectivities lead to a finite
analog of chaotic dynamics.
This behavior with various elaborations
has been interpreted by Kauffman in
many ways: 1) as self-organization
from complete disorder, 2) as a first
step in the origin of life, 3) as
epigenetic canalization in development,
4) as the self-organizing
structures on which Darwinian natural selection
can operate, but cannot
override, and 5) by allowing variation in
connectivities and by coupling
nets, a model of meta-evolution where
natural selection (coevolution)
chooses the "edge of chaos" as the most
adaptive condition.
It is
fair to say that Rosen and Kauffman never formed more than a civil
relationship that is usual at professional meetings. Kauffman has much
more
personal ambition than did Rosen and achieved a notoriety that in
my
opinion (and Rosen's and many others) is not justified by hard
evidence
supporting his imposing claims for his models. Rosen saw the
behavior of
random nets as an obvious example of the generic behavior of
discrete
dynamical systems. He saw Kauffman's many interpretations as
simply
illustrating that the same formalism can be encoded any way you
like.
On the other hand, Kauffman has suggested biological
observables that would
allow empirical tests of his models. His books
include biological evidence,
and are written with conventional language
that biologists understand well
enough to critically discuss. Kauffman
criticizes Rosen (as have I and
others) for his imposing claims written
in a language that few biologists
understand, and that have as yet
suggested no biological observables that
could allow a verifiable
model.
I don't think any of these criticisms, while probably true,
are
scientifically relevant. My current view is that Rosen and Kauffman
are
thinking on different levels. Rosen's thinking is primarily on an
epistemic
model. One might call it a general principle that any
biological model must
satisfy to answer a "Why?" type of question. After
all, the modeling
relation itself is a model. It is based on the Hertz
condition that is not
itself empirically verified except that a model
must satisfy it to give us
the answers we want. An analogy is the
symmetry principles of physical
models. These principles are not
empirically testable. They are epistemic
conditions we discover we must
place on empirical models to give us the
types of explanation or answer
to the questions we ask.
Kauffman, on the other hand, has a simple
computer simulation that behaves
by various interpretations like
developing organisms and like an evolving
population. If I had to say it
in < 20 words, Kauffman has empirical models
without a specific
epistemology; Rosen has an epistemology without (as yet)
specific
empirical models.
Howard