This study focuses on the emergence of the principle that nuda pacta are binding. As these kinds of contracts rose to prominence within the entire ‘ius commune contract system’, the interpretative skills of generations of glossators and commentators would be put to the test over the problems such contracts raised. Thus, not only is this one of the most appropriate contexts in which to analyze the innovations introduced by medieval jurisprudence in comparison with Roman law, but it also represents an occasion to examine the efforts and depth of reasoning employed by the first legisti. Though it may seem paradoxical, contract law emerged for the first time relatively late in historical terms, specifically in the works of sixteenth- and seventeenth-century European jurists. There was no contractual model in the preceding centuries; even in the Middle Ages, the prevailing practice for reaching an agreement necessitated outward expressions of consent, resulting in verbal contracts at the very least, and real contracts at the most. Only with the affirmation of Humanism, when the debate shifted from the procedural level to the substantive level, did sixteenth-century jurists attribute a central role to the concept of contractus. In so doing, a common framework was established under which different forms of agreements could come to be qualified as ‘contracts’. In the seventeenth century the debate came to accept the binding nature of contracts, thereby uniting theoretical and practical needs under one school of thought. That, combined with the increasing economic development of the time and inaction on the part of legislators, led to a new, more balanced contractual framework, wherein the raison d’être of one party’s obligation was finally to be found in the reciprocal obligation of the other party. Nonetheless, the need for a contractual archetype would not be met until codification.