In response to Mason's first question, this is my understanding of Mises' view of math and logic: Mises refers to his own method of constructing theories of human action as "praxeology." It is different from both purely logical reasoning and math. "Logic and mathematics deal with an ideal system of thought. The relations and implications of their system are coexistent and interdependent. We may say as well that they are synchronous or that they are out of time. A perfect mind could grasp them all in one thought. Man's inability to accomplish this makes thinking itself an action, proceeding step by step from the less satisfactory state of insufficient cognition to the more satisfactory state of better insight. But the temporal order in which knowledge is acquired must not be confused with the logical simultaneity of all parts of an aprioristic deductive system. Within such a system the notions of anteriority and consequence are metaphorical only. They do not refer to the system, but to our action in grasping it. The system itself implies neither the category of time nor that of causality There is functional correspondence between elements, but there is neither cause nor effect. "What distinguishes epistemologically the praxeological system from the logical system is precisely that it implies the categories both of time and of causality. The praxeological system too is aprioristic and deductive. As a system it is out of time. But change is one of its elements....So is the irreversibility of events. In the frame of the praxeological system any reference to functional correspondence is no less metaphorical and misleading than is the reference to anteriority and consequence in the frame of the logical system." (pp. 99-100, Human Action, 1966 ed.) My understanding of Mises's claim is that economic theorizing must always include the time dimension as a part of the actor's choice context because human action itself always takes place in real time and involves cause and effect. In understanding acting in the temporal order, and deriving principles of action, there must be a theoretical role for inconsistency--in contrast to both math and logic, where consistency can occur because of the assumed simultaneity of all parts of the argument. In many other places Mises argued that math functions are useless in economic theorizing because there are no constant relations between variables in human action. Math is confined to simple pedagogical uses as a shorthand to present theory in simpler form. In answer to Mason's second question, I'm not sure that it is quite fair to say that the people at the Mises Institute "write in Mises' name." They apply their understandings of Mises, Rothbard, and others' theories to specific policies set in an historical context like the people at Brookings, AEI, Heritage, etc. Those who believe that "theory" must always reflect the historical context and personal characteristics (psychology, culture, sex, etc.) of specific acting human beings are never going to accept the application of any "general" theory, whether it is that of Mises, Keynes, Stiglitz or Marx. Samuel Bostaph