This article scrutinises one of the mainstream views of how one grows into responsible membership of society; the view based on Jürgen Habermas', Lawrence Kohlberg's and Jean Piaget's theories. Habermas praises Kohlberg's and Piaget's psychological theories and uses them as empirical sources crucial for his theoretical work. We argue that this view should be revised in light of new empirical findings as Habermas' Kohlberg's and Piaget's view is based on a false understanding of the development and functioning of human reason and morality. We do not, however, defend a view that reduces normative questions to empirical facts. In contrast, we agree with Habermas that in an adequate (educational) theory, both philosophical and empirical dimensions have to be taken into account but argue that the empirical research results he has utilized are fallacious in light of current research findings. Finally, we discuss the relevance of our argument for educational theorisation.