From: Crosby_M (Crosby_M@bls.gov)
Date: Sat Apr 12 1997 - 17:40:37 MDT
On Thursday, April 10, 1997, I suggested:
When dealing with human health, moods and cognitive capacities, we are
dealing with a VERY complex system that does not submit to simple
mechanical measurements.
Lee Daniel Crocker responded:
<So complexity tells you that you should just give up? Nonsense. I
do not concede for one moment that there exists anything I am not
capable of measuring, testing, and understanding /eventually/. It may
be very difficult; we may not even know how to begin going about it
yet. But anything we experience is measurable, without exception, if
we take sufficient care in the experiment. Even if our experiments
are sloppy and our conclusions vague, we're still better off than
someone who doesn't even try.>
I said nothing about giving up. I said /simple mechanical
measurements/ were not very useful. Lee described experiments he
performed to test the efficacy of melatonin and aspirin. The aspirin
vs. acetaminophen experiment, in particular, seems similar to what I
would do when trying to evaluate some new supplement or nootropic
substance.
I think the following is relevant to the types of measurement problems
I had in mind:
<It is important to emphasize this epistemic necessity of the
complementarity of laws and measurements since it is often ignored.
Reductionists try to avoid the epistemic cut and take an entirely
objective, unified, or reified view of information as if it exists in
the structures of the physical world independent of an organism or
observer. Such a view is possible only because formal or structural
information measures can, in fact, be applied to any physical
structure without regard to its epistemic function in construction,
measurement, prediction, or control. That is, structural information
measures need have no relation to fitness, function, or meaning. This
gratuitous use of structural information measures, while it may be
made formally consistent with physical theory, simply has no
significance for the naturally selected semantic information in
biological systems and for predictive information used in control
systems. >
The above is from a paper by Professor Howard Pattee called "The
Physics of Symbols and the Evolution of Semiotic Controls" that was
presented to a Workshop on Control Mechanisms for Complex Systems at
the Santa Fe Institute last December. It can be accessed at
http://ssie.binghamton.edu/people/pattee_docs/semiotic.html
The abstract of Pattee's paper is also worth quoting:
<Physical laws and semiotic controls require disjoint, complementary
modes of conceptualization and description. Laws are global and
inexorable. Controls are local and conditional. Life originated with
semiotic controls. Semiotic controls require measurement, memory, and
selection, none of which are functionally describable by physical laws
that, unlike semiotic systems, are based on energy, time, and rates of
change. However, they are structurally describable in the language of
physics in terms of nonintegrable constraints, energy degenerate
states, temporal incoherence, and irreversible dissipative events. A
fundamental issue in physics, biology, and cognitive science is where
to draw the necessary epistemic cut between the coherent physical
dynamics and its rate-independent semiotic description.>
Mark Crosby
P.S. For those interested in the subject of Artificial Life, there is
another excellent paper at the SUNY Binghamton server by Luis Rocha
called "Evolutionary Systems and Artificial Life"
http://ssie.binghamton.edu/~rocha/ss504_02.html
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