What is the Aristotlean and Thomasian epistemological position?

In his ‘defense of extreme a priorism’ rothbard writes :

Whether we consider the Action Axiom “a priori” or “empirical” depends on our ultimate philosophical position. Professor Mises, in the neoKantian tradition, considers this axiom a law of thought and therefore a categorical truth a priori to all experience. My own epistemological position rests on Aristotle and St. Thomas rather than Kant, and hence I would interpret the proposition differently. I would consider the axiom a law of reality rather than a law of thought, and hence “empirical” rather than “a priori.”

What is the epistemological position he references and how does it vary from the Neo Kantian position of Mises?