I have a few conjectures (87 lines worth) as to what Michael 
Perelman [OPE-L:1207] might have in mind by the notion of Marx 
"using his analysis of values as a means of showing . . . the 
weakness and vulnerabilities of capitalism".  Let me know if I'm in 
the right zone, Michael.  Then perhaps we can develop a more precise 
(not necessarily more quantitative) set of conceptualizations.
    One possible starting point is the venerable contradiction 
between use value and exchange value.  Here, capital depends on use 
value not just in the sense that commodities must have a use value in 
order to contain value (to be objectifications of SOCIALLY NECESSARY 
labor time) but also in the sense that capital (self-expanding value, 
money begetting more money) depends, from the standpoint of 
society as a whole, on the presence of exploitable labor power and 
the material and social conditions conducive to its exploitation.  
This labor power, in order to be exploited, has to be capable of 
expending useful labor where `useful' is defined in terms of the 
historically developed social and material conditions of production.
    An important aspect of this set-up is that there are a lot of use 
values that capital requires, but which it might not be capable of 
adequately reproducing in and through its own relations of 
exploitation and commodified (value-formed) socio-material 
reproduction.  True, capital normally has no problem `freely 
appropriating' such use value requirements insofar as they already 
exist.  Indeed, Marx spends a lot of time in various places 
discussing how capital accumulation (exploitation of wage labor, 
reinvestment of surplus value thus extracted, etc.) to a significant 
extent lives off of capital's free appropriation of natural and 
social conditions of production that are not directly reproduced by 
capital itself.  But, in the case of natural conditions required for 
socio-material reproduction, Marx points out that capital actually 
tends to corrode these use value requirements for its own expanded 
reproduction.  He also suggests, though less consistently, that 
capitalism would have trouble producing the kinds of people required 
to operate increasingly socialized, scientific-knowledge-based forces 
of production in the individual and collective interests of society 
as a whole.  (True, at some points he seems to suggest that the 
`universal-social individuals' required for the eventual transition 
to a higher form of socio-material reproduction will be more-or-less 
naturally evolved within the womb of capitalism itself; however at 
other times he is clearer in his suggestion that these universal-
social individuals must be a product of self-conscious class struggle 
conducted by and for the working class.)
    I think Mike Lebowitz's various efforts to extend Marx's analysis 
to incorporate `the political economy of wage labor' are consistent 
with the above theme of capital not being able to, by itself, ensure 
its own use value requirements.  In this sense, also, capital's 
dependence on `domestic' labor and production processes which are 
undervalued under commodified reproduction has a formal similarity to 
capital's dependence on natural conditions of reproduction which 
capitalism only ascribes value to insofar as they require social 
labor time for their appropriation in/for material production.  (I 
leave out the issue of rents for now; my opinion -- developed briefly 
in a forthcoming piece in SCIENCE & SOCIETY -- is that rents cannot 
offset capital's tendency to erode its own natural conditions either 
qualitatively or quantitatively.  Of course, the extent to which 
rents are capable of countering capital's tendencies to destroy its 
own socio-material conditions of existence could be a subject we 
might want to consider under the general theme of "value and the 
weakness and vulnerabilities of capitalism".  A related question we 
could consider is how Marx's approach to `free appropriation' differs 
from neoclassical externalities theory.)
    One question implied by the above (semi-coherent at best?) 
considerations could be:  If some of capitalism's tendencies toward 
social and material reproduction crises are due to its undervaluation 
of certain natural and other socio-material conditions of production, 
then how would a socialist society correct such undervaluation?  Or, 
if labor and nature are each sources of wealth (as Marx repeatedly 
emphasized), but value only recognizes labor as a source of wealth in 
its specifically capitalist form, then how would socialism correct 
this imbalance?  Personally I am impressed by some of Bettelheim's 
considerations on this issue in his book ECONOMIC CALCULATION AND 
FORMS OF PROPERTY.  Perhaps we could take that up later if a 
discussion of socialism materializes on the list. 
    I am not sure how the above relates to the discussion of 
valuation of means of production.  Perhaps someone could indicate 
whether, and how, they think different views on the valuation 
question might be associated with different perspectives on the 
contradiction between social production and private appropriation.  I 
know Michael Perelman has written some stuff arguing that problems 
with capital valuation manifest precisely this contradiction -- i.e., 
the fact that capitalist (value) relations are increasingly incapable 
of handling socialized, scientific-knowledge-based productive forces. 
    Well, after so little I'm already tired.  Paul B.