Contractual obligation and the journey from natural law to constitutional law

The bold promise of the Constitutional Court’s first foray into the field of contract law during Langa CJ’s leadership remains unfulfilled. This paper takes issue with both the Supreme Court of Appeal’s reticent reaction to Barkhuizen v Napier and commentators’ criticism of the CC’s preference for indirect horizontal application of the Bill of Rights. Proposing an expansive understanding of the reach and force of indirect horizontal application, it argues that the Bill of Rights requires a new, constitutionally-informed, conception of the normative foundations of contractual obligation in place of the natural law approach of the Roman-Dutch tradition as articulated by Grotius. Such a conception does not treat the enforcement of contracts as tantamount to enforcing a duty to keep one’s word, a duty of virtue, but as supporting the consensual creation and vindication of interpersonal rights when it is in the public interest to do so. The SCA’s continued rejection of good faith, fairness and reasonableness as principles on which parties and courts can rely directly, as opposed to abstract values underlying operational rules and principles, are shown to rest on a conception of contractual obligation that is incompatible with the constitutionalisation of South African law.