----- Original Message -----
Sent: Wednesday, January 12, 2005 9:42
PM
Subject: Re: [ROSEN] Why four categories
of causation?
Arno,
AG:
> For instance, in the famous
diagram of fig.
> 10.C.6 in LI there is an interesting double relation
between Phi,
> B and F:
>
> 1) B is material cause (Phi
being efficient cause and F outcome)
> 2) B is efficient cause (F
material cause, Phi outcome)
>
> So the 'really' interesting
point, I think, is: what does this
> relation between B and F look like,
apart from the definition of
> these various causal relations? There
MUST be some kind of
> ambiguous process going on, that can be
interpreted as material
> or efficient relation, but how do these two
relations mix up in
> their physical realization? It is in answering
such questions, I
> think, that Aristotle's causal system may not be
sufficient here.
The questions about the realization of this model has
haunted me for about as long as I have known of it. I still have difficulty
fully understanding the replication mapping Beta insofar as its meaning in
physical terms. I believe B as an efficient cause in ch. 10 of LI is related
to Rosen's comments waaay back in ch.6 on p. 157 about evaluation maps. There
he talks about how one could equally write s(f) for f(s). (I know it
should be an s with a circumflex over it, but this is the closest symbol
I could find in Outlook.) The example he uses for the physical interpretation
of the evaluation map is that of a meter: the meter value is caused
by s forcing the meter (which is designed to respond in a predetermined
manner) such that a certain meter value results, so s is more naturally
seen as the efficient cause rather than s being considered an "input" (i.e., a
material cause) to f.
In a similar way, if we have the repair mapping
F:B ® H(A,B)
then the evaluation map b Î B is
b:Fb ® H(A,B)
So, as I read this, a metabolic output b
is to be considered as a forcing upon the process F, thereby causing a certain set of mappings H(A,B).
The inverse of the evaluation mapping is
b-1:H(A,B) ® Fb
But, since Fb
is the mapping B ® H(A,B), then the inverse of
the evaluation mapping can be rewritten as
b-1:H(A,B) ® H[B ®
H(A,B)]
which is the desired replication mapping b.
I can understand how, using the meter analogy,
some 'input' b to F can be actually be the forcing
agent, causing F to produce a certain set of
mapping H(A,B). Of all that is unclear to me, the most unclear is the physical
interpretation of the inverse mapping. In that case, there is a set of
mappings H(A,B) which are forced (by b-1)
to produce a certain set of repair components. If H(A,B) is the set of
mappings which include the metabolic 'enzymes' (such as f), then
this seems to me to say that the set of 'enzymes' (or perhaps better, the
creation of 'enzymes'?) are being forced in such a way as to result in a
certain set of repair components.
It would probably help if I somewhat
understood "the embedding of a vector space into its second dual". Rosen
refers to the evaluation map as an abstract version of this [Found. of Math.
Bio. 1972, Vol. 2 p. 235 and BMB Vol. 21,p. 116, 1959].
Any ideas or thoughts?
Regards,
Tim