This article investigates the underlying themes and principles that inform curriculum debate and how they are articulated in current school policy discussions. This topic is approached with the help of a case study covering the debate on which subjects should be mandatory for students at the upper secondary school curriculum in Sweden. The focus is on the arguments for and against the inclusion of History among these core subjects. The aim is to order and structure this debate and to link the arguments found to basic underlying principles. Why was History considered important or unimportant? What arguments are found about the best way to teach History? This study employs a 4-fold distinction which distinguishes between perennialism, essentialism, progressivism, and reconstructivism as four schools of thought, each outlining its own particular view on what kind of knowledge is important and how such knowledge should be taught. One major finding is that two of the schools--progressivism and essentialism--completely dominate the debates under study. There existed a major fault line between those who emphasized the instrumental value of History as a tool for fostering good citizens, and those who considered History part of essential general knowledge about society. (Contains 1 note.)