Epistemologists have recently started appealing to the moral philosophy literature on interpersonal trust in order to help explain the epistemology of testimony. We argue that epistemologists who have given trust a significant role in their accounts of the epistemology of testimony have appealed to very different conceptions of the nature of trust, which have inevitably influenced the shape of their epistemological theorizing. Some have employed accounts of the nature of interpersonal trust according to which trust is a practical phenomenon subject (...) to the will and to practical reasoning. Such accounts face the task of showing how the practical phenomenon that is interpersonal trust has epistemic implications for testimonial belief. Other theorists have employed accounts of the nature of interpersonal trust according to which trust is at least partly a cognitive phenomenon, itself subject to epistemic norms. Such accounts do not face the task of showing how practical rationality has implications for theoretical reason. Instead, they face the rather different tasks of showing how it is that cognitive trusting bears genuinely interpersonal features, and of how theoretical rationality can share features with practical rationality. (shrink)