As appeals to expert authority shift from “fallacies” to “argument schemes,” argumentation theorists are called on to provide critical questions for assessing them. I argue that current treatments focus too heavily on assessing expertise, and not enough on judging trustworthiness. I propose instead a norma-tive pragmatic account of the rational force of the appeal to expert authority, one that emphasizes the ex-pert's actions in constructing his/her own legitimate trustworthiness.