Jon Irenicus:Mises argued for the categories' connection to reality on the ground that minds that are attuned to reality in such a way survived the process of natural selection; i.e. they are the minds best equipped to deal with the real world. I wonder if Hoppe holds a similar view. He sees action as directly tied to reality. There is a problem in Mises's (and any Kantian who adopts a similar line) view though, in that this is question begging. One thing about causality, is that denying it is self-contradictory.
I figure Mises offered natural selection as a metaphysical proposition -- reasonable, but by no means can it be established: "We are not prevented from assuming", etc. (Ultimate Foundation p15). But the existence of the categories must simply be accepted as an ultimate given.
Regarding the connection between a priori categories and the real world:
Although logic,mathematics, and praxeology are not derived from experience,
they are not arbitrarily made, but imposed upon us by the world
in which we live and act and which we want to study.
They are not empty, not meaningless, and not merely verbal. They are
—for man—the most general laws of the universe, and without
them no knowledge would be accessible to man.
The a priori categories are the endowment that enables man
to attain all that is specifically human and distinguishes him
from all other beings. Their analysis is analysis of the human
condition, the role man plays in the universe. They are the force
that enables man to create and to produce all that is called
human civilization. (Ultimate Foundation, p14)
For Mises, reality is defined by action:
5. The Reality of the External World
From the praxeological point of view it is not possible to
question the real existence of matter, of physical objects and of
the external world. Their reality is revealed by the fact that
man is not omnipotent. There is in the world something that
offers resistance to the realization of his wishes and desires. Any
attempt to remove by a mere fiat what annoys him and to
substitute a state of affairs that suits him better for a state of
affairs that suits him less is vain. If he wants to succeed, he must
proceed according to methods that are adjusted to the structure of
something about which perception provides him with some
information. We may define the external world as the totality of
all those things and events that determine the feasibility or
unfeasibility, the success of failure, of human action. (Ultimate Foundation, p6)
http://mises.org/books/ultimate.pdf
As for Hoppe, I have not caught him speculating on the origin of the categories. Off hand, it doesn't seem like something he woud do. In Defense, where he argues against hermeneutics, he concludes with this about the connection between action-as-language and reality:
Language, then, is not some ethereal medium disconnected from reality,
but is itself a form of action. It is an offshoot of practical cooperation and
as such, via action, is inseparably connected with an objective world. Talk,
whether fact or fiction, is inevitably a form of cooperation and thus presup-
poses a common ground of objectively defined and applied terms.Not in the
sense that one would always have to agree on the content of what was said
or that one would even have to understand everything said. But rather, in the
sense that as long as one claimed to express anything meaningful at all, one
would have to assume the existence of some common standards, if only to be
able to agree on whether or not and in what respect one was in fact in agree-
ment with others, and whether or not and to what extent one in fact understood
what had been said. And these common standards would have to be assumed
to be objective in that they would involve the application of terms within reality.
To say, then, that no common ground exists is contradictory. The very fact
that this statement can claim to convey meaning implies that there is such com-
mon ground. It implies that terms can be objectively applied and grounded
in a common reality of action as the practical presupposition of language.(Defense p183 RAE3_1)
http://mises.org/journals/rae/pdf/RAE3_1_16.pdf
Hoppe does not pass up any performative contradictions.
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