A Comparative Study of the Limitations on the Principle of Freedom of Will in Contracts under Swiss Law and Iranian Civil Law

Abstract

The principles of autonomy of will and freedom of contract constitute fundamental foundations of private law, allowing individuals, within the limits of the law, to decide whether to enter into contracts, select their contracting parties, determine contractual forms and terms, and regulate the legal effects of their agreements. However, economic and social developments, the expansion of standard-form and adhesion contracts, growing information asymmetry, and unequal bargaining power have demonstrated that formal consent does not always reflect genuine contractual freedom. Consequently, modern legal systems impose various limitations on private autonomy in order to prevent the abuse of contractual freedom. Using a descriptive-analytical method and a comparative approach, this study examines the limitations on freedom of will in Iranian civil law and Swiss law. The findings indicate that mandatory rules, public order, and good morals constitute the principal general limitations on contractual freedom in both legal systems. Nevertheless, Swiss law provides a more systematic and extensive role for personality rights, good faith, protection of weaker parties, and control of serious contractual imbalance. Iranian law also contains significant protective capacities through Article 10, Articles 960 and 975 of the Civil Code, rules governing defects of consent, civil liability, and certain consumer-protection provisions; however, these mechanisms have not yet been developed into a fully coherent and integrated theory of substantive contractual freedom. The comparison further shows that a major difference between the two systems lies not merely in the existence of restrictive legal rules, but in their interpretation and practical application, particularly through judicial practice. Accordingly, the future development of Iranian contract law should preserve contractual autonomy and transactional security while strengthening protection for genuine consent, personality rights, contractual transparency, good faith, and minimum standards of fairness in structurally unequal contractual relationships.