You are correct; I missed your main point.  
  
Methodological expositions always have underlying epistemological and  
metaphysical "stances"--whether their authors are aware of them or not.  So  
far as I know, assumptions about the ground of being are not provable but  
consist of statements like "I think, therefore I am" (Descartes); "I am,  
therefore I must think" (Rand); or "Only I am" (simple-minded solipcism).  
  
Mises's methodological "exposition" merely spins out the implications for  
praxeology (and economics) of the metaphysical assumption that human beings  
exist physically separate from one another, but reason can explain their  
interactions--those interactions themselves having no physical existence.  
He uses a lot of assumptions concerning the nature of human beings and human  
consciousness that are themselves subject to argument and lead to the sort  
of discussions that Bruce Caldwell would like to see ended.  
  
Samuel Bostaph