Citing an epistemic or cognitive asymmetry between experts and the public, it is easy to view the relation between scientists and citizens as primarily based on trust, rather than on the content of expert argumentation. In criticism of this claim, four theses are defended: Empirical studies suggest that content matters, while trust boasts persuasiveness. In social policy controversies, genuine expert-solutions are normally not available; if trust is important here, then a clear role for cognitive asymmetry is wanting. Social policy controversies (...) pivot on values, so that biases and ideologies may explain participant behavior. Few experts communicate perfectly; rather than cognitive ones, one might cite social differences. (shrink)