Legal pronouncements to the effect that such and such is the case can be divided into three categories, which the paper calls normative, constitutive, and epistemic. The paper defines these three legal categories, explores examples of each of in the law of the state, and then examines church pronouncements under the same categories to see what light the analogy of secular law can shed on them. The Church's assertions of authority regarding faith and morals are epistemic in nature. Epistemic pronouncements by authority, whether in Church or state, are binding on anyone who is not better informed than the author, but generally not on anyone who is. The paper suggests that this principle can be used to evaluate the binding force of different pronouncements of the magisterium.