Let me start by asking what is wrong with the position taken by Mises and so many others that the choice between values is ultimately arbitrary? First, it should be noted that such a position assumes that at least the question of whether or not value judgments or normative statements can be justified is itself a cognitive problem. If this were not assumed, Mises could not even say what he evidently says and claims to be the case. His position simply could not exist as an arguable intellectual position.
At first glance this does not seem to take one very far. Indeed, it still seems to be a far cry from this insight to the actual proof that normative statements can be justified and that it is only the libertarian ethic which can be defended. This impression is wrong, however, and there is already much more won here than might be suspected. The argument shows us that any truth claim, the claim connected with any proposition that it is true, objective or valid (all terms used synonymously here), is and must be raised and settled in the course of an argumentation. Since it cannot be disputed that this is so (one cannot communicate and argue that one cannot communicate and argue), and since it must be assumed that everyone knows what it means to claim something to be true (one cannot deny this statement without claiming its negation to be true), this very fact has been aptly called “the a priori of communication and argumentation.”
Arguing never consists of just free-floating propositions claiming to be true. Rather, argumentation is always an activity, too. However, given that truth claims are raised and settled in argumentation and that argumentation, aside from whatever it is that is said in its course, is a practical affair, it follows that intersubjectively meaningful norms must exist—precisely those which make some action an argumentation—which have a special cognitive status in that they are the practical preconditions of objectivity and truth.