  As well as asking how constraints might be clarified, we must ask how they might be defended. One type of defence proceeds from within our theory of ideals. A theory of ideals includes an account of the values that bear upon how we should act, and of the priority relations between those values (Hamlin and Stemplowska 2012). To see how such a theory might generate constraints, consider (W). One argument for that principle is the argument from conviction (Simester and von Hirsch 2011, 19–20):