This essay explores the nature of the curriculum content of liberal studies--a core school subject in the new senior secondary curriculum in Hong Kong--with reference to the curriculum-making processes entailed in the formation of that subject. The central thesis is that a school subject is introduced to schools and classrooms as a distinct representation of content embodied in curriculum materials, entailing a theory of content--a special way of selecting, organizing, and framing the content for social, cultural, educational, curricular, and pedagogical purposes. Knowing the content of a school subject thus entails knowing more than the content "per se"; it entails an understanding of the underlying theory of content, which is necessary for disclosing and realizing the educational potential embodied in the content. (Contains 1 table and 16 notes.)