Anthony Waterman wrote:   
> What is 'methodological individualism'? As I understand   
> it, it  is the working assumption that human social   
> phenomena may be explained without remainder as the   
> outcomes of action by individuals: and that any additional   
> explanans (e.g. 'collective' plans, intentions etc., 'laws   
> of history', 'general will' and so forth) are redundant.   
> There can be no 'proof' of the 'correctness' of this   
> working assumption. It is part of the 'hard core' of   
> economics' which we stick with so long as the models we   
> construct on that basis seem to work.  Why are we   
> quarrelling about this? And how could it possibly need   
> a defence?   
  
  
It is hard to know where to begin with such a broad   
question.  I'm somewhat inclined to a response as effortless  
as the question:  
http://scholar.google.com/scholar?q=%22methodological+individualism%22&ie=UTF-8&oe=UTF-8&h
l=en&btnG=Search
  
As you suggest in your post, methodological individualism  
is often more of an ideological commitment than an  
explanatory strategy.  And it tends to remain   
correspondingly vague in its actual explanatory commitments,   
to the point that the profession has founds itself smiling   
upon the ad hoc device of a "representative agent" as being   
somehow methodologically individualist.  
  
If I proposed as a working assumption that human social   
phenomena may be explained without remainder as the outcomes   
of action the natural laws of the physical universe, and   
that any additional explanans (e.g. plans, intentions, will,   
etc.) are redundant, I suppose at some level it would be   
hard to object.  But surely there are pragmatic objections.  
As in your definition above, the word "may" bears astounding   
weight.  
  
Again, thinking a bit about the neoclassical theory of the   
firm can be very helpful: although pervasive, the absence of   
an serious commitment to "methodological individualism" in   
our profession is seldom as stark.  
  
Cheers,  
Alan Isaac