The terms "ideal theory" and "nonideal theory" are used in contemporary Anglophone political philosophy to identify alternative methodological approaches for justifying normative claims. Each term is used in multiple ways. In this article Alison M. Jaggar disentangles several versions of ideal and nonideal theory with a view to determining which elements may be helpful in designing models of real-world justice that are contextually relevant, morally plausible, and practically feasible.