Luigi Einaudi (1874-1961) was a leading liberal economist, economic historian and political figure. This book provides the English-speaking world with a first critical edition of Einaudi’s – hitherto unpublished – rewriting of one of his most unique and thoughtful essays.The relevance of this essay is crucial from several perspectives: history and methodology of economic thought, role of economics and its relation to other disciplines and to social values, role of economists in the public sphere, while also encompassing the discourse on man and the economist as a "whole man". The critical edition of On Abstract and Historical Hypotheses and on Value Judgments in Economic Sciences includes a comprehensive introduction and afterword. An extensive reappraisal of this newly discovered essay will help to cast light on Einaudi’s uniqueness and originality within and beyond the Italian tradition in public finance, thereby also illuminating his attempt to provide an epistemological account of his long lasting enquiry into the causes of good and bad polities.This book is of great interest to those who study economic theory and philosophy, as well as history of economic thought, public economics and legal and political philosophy.