Based primarily on the epistemology proposed by Karl Popper, this essay aims to show how the most effective method for explaining human action, and thus also the decisions of a political or administrative institution, is based on the principle of causality, the principle of rationality, and the principle of falsifiability. An attempt will be made to show the complementary nature of these three fundamental methodological tools, highlighting how they combine to define an epistemological paradigm capable of raising the standard of scientificity of explanations in the social sciences. After defining this theoretical model, the final part of the chapter examines a case study: the explanation proposed by Sabino Cassese of some dysfunctions in the Italian public administration. The implicit epistemology on which this explanation is based is reconstructed, showing how the author uses precisely a Popperian epistemological model based on the principle of causality, the principle of rationality, and the principle of falsifiability.