Reply to Roederer and Holgate

Dear Juan:

Thanks for the clarifications. We are indeed very close to each other in
our thinking. I could not agree more with your characterization of the
problem---to understand how one can get from a purely energetic coupling
to a coupling that is controlled by the low-energy informational link,
not the higher-energy interactions occurring at either end of the link,
or in the space in between. That is indeed the very essence of the
puzzle, of life and of mind, in my view.

On the mobilization of stored energy Ho has interesting things to say,
and on the nature of the low-energy informational "coupling", Rod
Swenson and others have written insightfully. But I think it is fair to
say that no one really understands what to make of the existence of such
a situation, from a physical point of view. But getting clear on what we
need to explain is of course a major accomplishment in itself.

Re: biomolecular examples of this basic type of informational
"coupling"---what about enzymes? They seem to interact with their
surrounds via low-energy, noncovalent bonds in a way that is at least
somewhat analogous to the informational coupling you describe. That is
why it makes sense to say that a pharmaceutical molecule which imitates
an enzyme's natural substrate closely enough to trigger a conformational
change via the low-energy interaction at the active site, but is
different enough to gum up the works when it comes to the enzyme's
high-energy functional action, has in effect "fooled" the enzyme. Here,
I believe, we are already seeing the roots of information use.

I agree with what you say about the origin of life. As I said, my
comments were largely "quibbles" to begin with.

Dear John H.:

When I speak of "purpose", I of course imply nothing about any
subjective experience in the system in question. In general, I try to
avoid the problem of consciousness (in the sense of qualia) as much as
possible. (For this reason, I would not like to equate purpose with
intentionality, at least not without a great deal of discussion.)

I believe that "purpose" can be given a perfectly objective sense, and
that it is closely tied to Juan's analysis of an information "coupling"
that cannot be explained by ordinary physics (although maybe it will be
some day by an extension of quantum field theory). At any rate, what
else would you call the goal-seeking behavior of cells?

In a nutshell, I view purpose (or natural teleology, or intelligent
agency) as consisting of two aspects, a striving or conative aspect, and
an instrumental or cognitive aspect. I believe that all living things
exhibit behavior that is best understood in this way, and that this is
just an objective fact about the world. How to explain it is of course
another matter.

I think that against a metaphysical backdrop of effective field theories
and emergent levels as one finds in the discussions of condensed-matter
physicists like Philip Anderson and Robert Laughlin, we can perhaps
begin to make sense of purpose in this sense. It is a property of the
particular form of the organization of matter that we find in the cell,
as opposed to a mere abstract relation that could in principle be
"realized" in any form of matter at all. Like Laughlin, Ho, Hans
Frauenfelder, Gerald Pollack, and others, I believe that the physics of
proteins and of the ordered-water-protein-phosphate gel must somehow be
crucial. However, at this point, this is admittedly more an article of
faith than any sort of a verifiable empirical postulate. But all the
other alternatives seem to me worse. I guess time will tell.

In short, one can ban the word "purpose" from the discussion, but one
cannot banish the phenomenon itself, for it is the very heart of the
problem we are discussing here at FIS.

James
Received on Thu Jun 20 18:11:13 2002