The Will in the Performance of the Obligation: between Coercibility and Spontaneity

Starting from the well-known definition of debtor contained in Mod. 4 pand . D. 50.16.108, according to which the debtor is the one from whom performance can be demanded even against his will ( invito ), this contribution aims to examine the reflections of classical Roman jurisprudence on the theme of the noncoercibility of the obligatory bond. In particular, it focuses on the voluntas of the solvens (and the potential relevance of its defects, especially error ) in cases of undue payment and in the case of a payment made sua sponte by the debtor. This analysis provides a foundation for evaluating the changes introduced in the transition from the 1865 Italian Civil Code to the 1942 Italian Civil Code on the subject of natural obligations, where the adverb ‘voluntarily’ was replaced, thus more faithfully recovering the Roman legal tradition, by the adverb ‘spontaneously’.