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 This book provides the English-speaking world with a first critical edition of an unpublished version of Einaudi's most important epistemological essay. The issues analysed here lie at the core of the problem concerning the nature and scope of economic sciences and the role played by economists in the public sphere, with particular emphasis on the interaction between economists and the ruling class. The earlier version of this essay has also been considered the "historical epilogue" of the Italian tradition in public finance. An extensive reappraisal of this newly discovered document will help to reconsider and cast light on that tradition. This critical edition includes a comprehensive introduction and conclusion, both of which aim to place Einaudi's essay in the context of his earlier epistemological speculation and the associated debates, and to assess the unsettled questions he left as an enduring heritage for the current generation of social scientists.