 These passages suggest the following account of the role and justification of definitions of morality in the work of Turiel and his collaborators, and of the way philosophy contributed to their project. As noted in  Section 3,  the philosophical literature played a role in designing the initial experiments that enabled Turiel to show that children distinguish different sorts of normative transgressions and thus that their normative judgments are not “undifferentiated”. The features probed by criterion judgment questions—authority independence and generalization to other places and other times—were suggested by the philosophical literature. Having shown that a modest number of schoolyard transgressions that seem, intuitively, to be moral evoke the (putatively) moral pattern of criterion judgments, a natural question to ask was how to characterize the full set of transgressions that would evoke moral criterion judgments. Characterizing that set of transgressions would constitute a “definition of morality”. Here again philosophy played a role by suggesting what Turiel, Killen, and Helwig (1987) characterize as their “working definitions” of the moral domain. Using such a working definition, Turiel and his colleagues could fine tune the transgression descriptions and criterion judgment questions used in their experiments. And sometimes the results of the experiments required modification of the working definition of morality, which expanded from matters involving justice, to justice, rights, and welfare or harm, and then expanded again to include matters involving fairness and equality. This back and forth between definitions and data-gathering procedures is the “recursive” strategy that Turiel, Killen, and Helwig (1987) were alluding to.