The article presents the results of author's research of the origins of the general concept of contract in continental legal science in the Middle Ages and early Modern Times. This general concept marks one of the key features of the legal style in civil law countries, unknown to Roman jurisprudence, Muslim fiqh or Anglo-American common law. The formation of the general concept of contract proves to be the outcome of several generations of jurists archived through the combination of two models of contract in the medieval ius commune: agreement-based (in the commentaries on Roman law) and promise-based (in the church canons). It is argues that the synthesis of the two models in the 16th century is due to the efforts to reduce the Roman classical law to an art (as in the case of the French humanists) or to explain every rule of positive contract law through the ideal concepts of natural law and commutative justice (as in the case of Spanish legal thinkers). In arranging contract law the French jurists (such as François Connan and Ugo Donellus) followed the intended project of Cicero (ius in artem redigere) by means of the methodology of Petrus Ramus. The representatives of the Spanish late scholasticism (Domingo de Soto, Louis de Molina, Leonard Lessius) aimed at explaining all the provisions of the positive contract law in the sense of the higher moral and theological principles of natural law, as it was laid out in 'Summa Theologica' by Thomas Aquinas. The author looks into the relevant works of the French and the Spanish jurists to analyse the definition of contract, its criteria, and to trace their origins in the legal commentaries of the medieval civilians and canonists, as well as in the medieval and antique treatises on moral theology and philosophy. The analysis allows for critical assessment of the inconsistencies and contradictions of the general concept of contract in the doctrines at the beginning of Modernity.
Dmitry Poldnikov (Sat,) studied this question.