PRINCIPLES AND THEORIES OF CONTRACT IN HISTORICAL RETROSPECT AND MODERN CIVIL LAW

Abstract

This article examines the historical evolution of the contract as a legal institution and its theoretical understanding in civil law. The contract is considered one of the oldest legal constructions that emerged alongside the development of property and the need to regulate property relations. Particular attention is given to Roman law, where contracts (contractus) became a key source of obligations and evolved from ritualized formal acts to more flexible agreements. The distinction between contracts and pacts reflected the balance between legal formalism and adaptability in the Roman system. The article also analyzes the influence of canon law, which expanded the meaning of contractual obligations by recognizing the legal force of oral promises and introducing the concept of causa as the legal purpose of a contract. This innovation laid the foundation for the modern doctrine of contractual liability, where the principles of good faith and conscientiousness play a decisive role. The intellectual context of the Renaissance and Modern periods is considered through the development of the social contract doctrine, particularly in the works of Jean-Jacques Rousseau, which emphasized the role of agreements in organizing social and political life. Special focus is placed on the nineteenth-century theoretical debates, including F. Savigny’s will theory, R. Jhering’s interest theory, I. Koller’s declaration of will, and combined as well as causal approaches developed by G. Jellinek, L. Michoud, O. Gierke, B. Windscheid, A. Brinz, and O. Lenel. It is emphasized that modern Ukrainian civil legislation incorporates elements of these theories by enshrining freedom of will expression, protection of legitimate interests, and recognition of contractual causa.