Theoretical and legal foundations of the principle of freedom of contract

The aim of this study is to comprehensively analyze the theoretical and legal foundations of the principle of freedom of contract in the Russian legal system through the prism of philosophical, constitutional, and civil law approaches. The article examines the philosophical and legal foundations of freedom of contract, tracing back to the concepts of Immanuel Kant and Bernard Spinoza, where reason is the determining factor in the boundaries of the autonomy of the will. It analyzes the constitutional and legal dimension of contractual freedom as a balance between the liberal concept of autonomy and the social dimension of constitutionalism in the context of structural inequality of bargaining power. The article examines the implementation of the principle of freedom of contract in civil transactions through a discretionary regulatory method, including the equality of parties, autonomy of will, and property independence. Particular attention is paid to the transformation of contractual relations under the influence of the digitalization of the economy, which has given rise to new forms of information and power asymmetry. This article examines the institutional boundaries of freedom of will, defined by imperative norms, requirements of good faith, and the protection of public interests. It also analyzes case law demonstrating the transition from formal equality to substantive justice through the development of the doctrine of unfair contractual terms. The author concludes that the principle of freedom of contract is a dynamic institution structured by three components: procedural autonomy in contract formation, substantive autonomy in determining the content, and the dynamic adaptability of obligations. The functional purpose of this principle is to ensure a balance between private initiative and public interests, legal certainty, and adaptability to economic challenges in the context of the digital transformation of civil transactions.