This article questions the basic assumptions of pedagogical content knowledge by analyzing the ideas of Jerome Bruner, Joseph Schwab, and John Dewey concerning transforming the subject matter. It argues that transforming the subject matter is not only a pedagogical but also a complex curricular task in terms of developing a school subject or a course of study. This curricular task, however, has been obscured by the concept of pedagogical content knowledge that construes transformation as primarily a pedagogical task in terms of transforming the subject matter of an academic discipline into pedagogical forms.