If we reject sentimentalist accounts of the nature of moral motivation and education, then we may regard some form of reason as intrinsic to any genuine moral response. The large question for moral education is therefore that of the nature of such reason--perhaps more especially of its status as knowledge. In this regard, there is evidence of some recent drift in both ethics and theory of moral educational theory towards more instrumental pro-social skill acquisition conceptions of moral reason as more methodologically amenable to the empirical research methods of contemporary social science. This article sets out to show that the work of three great philosophers--all of whom have continued to exercise significant influence on modern and contemporary moral educational theorising and research--points in various ways to more epistemically robust conceptions of moral reason as meaningful personally formative knowledge that is not so readily amenable to natural or social scientific understanding and explanation.