John,  
  
You have to place Mises in his philosophic context ... early Husserl and the
phenomenological tradition to see what he means by those terms and what he wants to do
with them and how that relates to the neo-Kantian movement in German language philosophy
circa 1920.
  
You cannot assume he means the same thing as we mean today.  So you may need to be a bit
more careful in your reading before claiming that Mises is beyond reason.  He fits clearly
in the continential traditions he is writing from.  You can disagree with him and even
disagree with an entire tradition, but to do that you have to step inside of that
tradition an find the gaps on its own terms.
  
Within the tradition Mises is writing in --- there is a strict dichotomy of the natural
and cultural sciences (e.g., see Dilthey).  Mises's original contribution was to argue
that in the sciences of human action you could derive "laws" that had the same ontological
status as the laws of the natural sciences (even greater condidence actually) but through
different epistemological procedures.
  
An excellent local source for understanding Mises would be Sam Bostaph at U of Dallas.  
  
Peter J. Boettke