Suppose two persons disagree over whether an act is right, justifying their judgments by appealing to divergent higher-level moral principles. These principles function as backing and rebuttals in their argumentation. To justify these principles, we may argue either that they would be accepted in some ideal model or that they are in reflective equilibrium with our considered moral judgments. Disagreement over the model indicates difference in philosophical anthropology but does not preclude resolution through argument.