South Africa’s Constitutional Court has adopted a purposive approach to interpreting the Constitution of 1996. It first signaled that it would take this direction in the early decision S v Mhlungu, concerning whether criminal cases pending at the time of the adoption of the Interim Constitution were subject to constitutional litigation. That decision became the focal point of scholarly disagreement about whether the purposive approach permitted the court to abandon the plain meaning of the constitutional text. Scholars and judges have increasingly come to support the purposive approach by invoking the idea of transformative constitutionalism i.e. that the Constitutional text itself mandates a break from the legal culture of the past. I evaluate this justification for purposivism and explore the controversy it has generated, particularly with respect to the Constitution’s influence on private law.