ABSTRACT“Ideals” are often invoked in contemporary theological discussion of moral norms, especially but not exclusively regarding norms of marriage/sex ethics. Seemingly absent from the discussion, however, is focused critical analysis of the distinction between ideal and mandatory normativity. Attempting to address this oversight, the following paper begins by highlighting a serious inconsistency between recent Catholic magisterial documents. It is proposed that the inconsistency is largely due to understanding the respective norms—relating to marriage and euthanasia—in divergent ways: per the very different (...) orders of ideal and mandatory normativity. After a philosophical clarification of the distinguishing features of ideal and mandatory normativity, one particularly indebted to the work of Joseph Raz, the paper illustrates how divergence between them operates to create the aforementioned magisterial inconsistency. This inconsistency is paralleled by neglect of—and consequent incoherence around—the ideal-mandatory norm distinction within wider moral theology. The last section considers how the distinction bears upon and helps illuminate the relationship between principles, rules, and rules' exceptions. (shrink)