Yes steve, even folks who are influences in ways that some others 
might judge to be misunderstandings are people who have been influences. 
In the selectionist picture of knowledge advance worked out by folks 
like David Hull and Gary Cziko, error in descent replication is a key 
element of the process of generating variation, upon which criticism and 
selection operate.  So all of the "Keynesian's" who took ideas from 
Keynes, but not exactly what Keynes thought, are folks in the chain of 
ideas the Keynes is responsible for.  Often, people who didn't quite get 
i, got things a bit differently than they were given to them, have made 
major advances to knowledge -- both inside economics, and outside it. 
 
I might recommend, on the whole issue of historical descent, and  
especially historical descent, the outstanding book of David Hull,  
_Science as a Process_.  Hull is widely regarded as the worlds leading 
philosopher of biology (he's so good most biologists think he is one 
of them -- he's not he's one of us [i.e. us philosophers].  Hull provides 
a first rate account of the debates in biology and paleontology over the 
tracking of 'family trees' in the organic world, and he also provides a 
leading new account of the the historical evolution of ideas -- the chains 
of thought through history. 
 
For an introduction to a selectionist view of the growth of knowledge, 
see Gary Cziko, _Without Miracles:  Universal Selection Theory and 
the Second Darwinian Revolution_.  Cziko provides a general history and 
a gutsy hypothesis about the structure of knowledge development. 
 
 
Greg Ransom 
Dept. of Philosophy 
UC-Riverside