Epistemology (the philosophy of knowledge) is important because it underlies the problem of truth in economics and in all other area of rational research and discourse. Epistemology is also relevant to conspiracies theories. As philosopher Robert Nozick pointed out, in the social sciences, invisible-hand explanations are always preferable because otherwise the conclusion is planted in the premises--a vindication of Adam Smith and classical-liberal economics! The Ptolemaic system of astronomy also faced an epistemological trap in explaining the movement of planets...