ABSTRACT
Abstract. Due to our lack of sources, we only know the essential stages of the long and winding path that leads Pareto from the theory of the final degree of utility to the theory of choice, which is the foundation of his Manuale di Economia Politica. We can still put forward the interpretation that his passage from one theory to the other was guided by the need, always deeply felt by Pareto, to give his theoretical line of reasoning foundations that were consistent with reality. Actually Pareto sees in the (for him) factual indifference curves not only the realistic foundation for the new exposition of pure economic theory, but also the guide to renewed empirical researches directed at giving quantitative bases to that theory.
