Re: models - branch fromf GM discussion

[Howard Pattee <***>]

John K wrote:
[snip]
My personal belief is that even new physics can't do it [encompass biology] without 
ceasing to be physics, and I think at the core that was Rosen's belief too, but talking 
about new physics is a way of getting the physicists to be a little more humble about the 
scope of their discipline and to really be saying that some "new science" is needed.. The 
new science in the Rosennean sense is Rosennean biology.

HP:
I know that Bob was irritated by some physicists, and for good reason, but that is a 
personal, not a scientific issue. The issue is what specifically does a ?new science? 
mean? This is the issue that I think must be clarified if Rosennean models are to be of 
more use to biologists. I have never been clear what else, besides irritation, Rosen had 
in mind by calling physics ?impoverished? beyond the view that physical laws are simply 
inadequate or incomplete for describing the essential character of life (or even the 
function of measurement), a view that many physicists have argued for many years.

Rosen agrees with physics in the basic Hertzian epistemological conditions for an 
?objective? model, i.e., the commutation or congruence of physical and inferential 
entailments. Rosen says, ?In fact, the congruences (modeling relations) which can be 
established between them are, I would argue, the essential stuff of science.?

Rosen also agrees that a clear boundary must be chosen between the model and the system 
being modeled (the epistemic cut). Rosen says, ?Obliterating the boundary would leave us 
with the entire universe; either all environment and no system, or all system and no 
environment. And we recall that, as von Neumann argued, such a boundary must be placed 
somewhere, ?if the method is not to proceed vacuously.??

Rosen also agrees with physics that a problem arises when we try to construct a model of 
a system that contains both physical and inferential entailments, measurement being the 
paradigm example in physics. In other words, when we want to ?objectify? the observer or 
the measurement by moving the epistemic cut to the right we have problems. Again, I quote 
Rosen:

?From what has been said above, the ?objectivizing? of the observer (i.e., pulling him 
entirely into the public, external world) amounts to replacing the boundary between 
subjective and objective by an ordinary boundary between a system and its environment, 
both now in the external world (on the left). Moreover, this must be done in such a way 
that what, formerly, was (subjective) inferential entailment in the observer now 
coincides with causal entailment in the ?objective? system that has replaced him. At the 
very least, there must be no less causal entailment in the system than there was 
inferential entailment in the subjective observer.?

This is the condition that physical law description alone cannot satisfy because 
inferential systems are symbol systems governed by local syntax over which universal 
physical laws have no necessary effects. It is generally recognized that physical laws 
cannot generate or cause symbolic language structures including mathematics. Nor can 
symbols generate or cause physical laws. It is just this disjoint character of laws and 
symbols that stimulates the field of biosemiotics as an essential complement to 
biochemistry.

Obviously Rosen also agrees with physicists that physical laws cannot satisfy this 
condition. He expresses it in his own terms, namely, that this condition is ?inconsistent 
with the tenets of mechanism? as Rosen defines mechanism. (All quotes above from Chapt. 
5, Essays on LI)

So far I do not see a significant difference of opinion. The only unresolved Rosen issue, 
then, is what aspects of physics does he think require change? Rosen?s primary assumption 
is that because physical laws are inadequate to model life there must be something 
fundamentally wrong with physics. Rosen says, ?For then the muteness of physics arises 
from its fundamental inapplicability to biology and betokens the most profound changes in 
physics itself.? (LI, p. 13)

What is Rosen?s basis for this assumption? Why would we want to change successful 
physical models because they do not describe complex systems they were never designed to 
model? Bohr made this point long ago: ?We do not use quantum mechanics to describe tea 
parties.? We do not use celestial dynamics to describe cells.

Let me be clear. I am all in favor of developing in more detail Rosennian models of 
biological systems. My question is: What is the purpose of these continuing gratuitous 
complaints about physics? No doubt some physicists need ?humbling? but that is another 
problem (probably more difficult that creating life!). Physics will not ?cease to be 
physics.? If a new science is needed for biological models, that is more than enough of a 
problem. Trying to discredit physics as well as reductionist models along the way is not 
only a waste of effort but also counterproductive public relations.

Howard