 According to Rawls, individual justice is theoretically derivative from social justice because the just individual is to be understood as someone with an effective or “regulative” desire to comply with the principles of justice. However, it is not merely social justice that Rawls understands in (predominantly) rationalist fashion. When he explains how individuals (within a just society) develop a sense and/or the virtue of justice, he invokes the work of Piaget. Rawls lays more stress than Piaget does on the role our affective nature (sympathy and the desire for self-mastery) plays in the acquisition of moral virtue. But, like Piaget, he stresses the need for a sufficiently general appreciation and rational understanding of social relations as the grounding basis of a sense of duty or of justice and he explicitly classifies his account of moral development as falling within the “rationalist tradition.” 