To stay away from metaphysics one has to know a good bit about it.#
To establish or verify “historical facts,” we must rely on the acceptance of numerous general hypotheses (theories); and to verify general hypotheses we must rely on the acceptance of numerous data representing “facts” observed or inferred at various times and places. We always must take something for granted, no matter how averse we are to “preconceptions”.#
The strength of belief in a hypothesis depends, even more than on any direct empirical tests that it may have survived, on the place it holds within a hierarchical system of inter-related hypotheses.#
Mill does not propose to put the assumptions of economic theory to empirical tests, but only the predicted results that are deduced from them. And this, I submit, is what all the proponents of pure, exact, or aprioristic economic theory had in mind, however provocative their contentions sounded.#Quoted in Gabriel Zanotti, “The Epistemological Implications of Machlups Interpretation of Mises’s Epistemology” (2015)