Kant was a rationalist and believed in a priori knowledge. Rand critized Kant for that. But I think most interestingly mises resolved the eternal conflict of can we know something about reality at all but setting up humans as "acting" entities:

"We must recognize that such necessary truths are not just categories of mind, but that our mind is one of acting persons. Our mental categories have to be understood as grounded in action." Hoppe

The the real insight from hoppe is that mises analysis is important not only for economy, but also epistemology