The problem with Buddhist ethics as natural law is that the soteriological goal is one of liberating oneself from the constraints of karmic causality to become an enlightened being. The traditional anthropological explanation of this paradox has been to ascribe the natural law ethics of kammic reward and punishment to the laity and the nibbanic path of escape from natural law to the monastics (King, 1964; Spiro, 1972). More recent scholars (for instance, Keown,1992; Unno, 1999) have challenged this dichotomy and argued that monastic ethics have always revolved far more around the exchange of accumulated merits for alms than the goal of enlightenment.