ABSTRACT
Kohlberg was profoundly moved by the horrors of the Holocaust. Indeed, he viewed his own theory as a response to the Nazi ethos that could sanction the murder of millions of Jews and as a response to prevailing social science systems that could provide no resources by which to combat genocidal ideologies. It is perhaps easy to see why Kohlberg would find Piaget's theory so appealing. Kohlberg was keen to show that there were lawful ontogenetic variations in how children formulated moral knowledge and that it was possible to appraise these various forms of moral knowledge along a continuum of adequacy. In 1971 Kohlberg wrote an important paper entitled "From Is to Ought: How to Commit the Naturalistic Fallacy and Get Away With It in the Study of Moral Development". The complementarity thesis suggests that the empirical status of the psychological theory has a bearing on what we are to think of the normative ethical theory.
