Trust from mistrust: When is trust rationally justified?

In this paper, we explore the social dynamics of trust, mistrust, trustingness, and trustworthiness. In a well-functioning group or institution, especially a group dedicated to inquiry (e.g., scientists, journalists), systematic mistrust by enough people ensures that most epistemic agents are in fact trustworthy, which in turn means that default trustingness outside of one’s area of expertise is a reasonable disposition or stance to adopt. At the same time, this means that in a poorly-functioning group that lacks systematic mistrust by enough people, default trustingness is not rational. We then argue that we should reject as too stringent any assumption that default trustingness amounts to irrational gullibility for three reasons. First, whether default trustingness is gullible depends on the norms and practices of the social epistemic structure in which one finds oneself. Second, people are often justified in trusting even when some might regard that trust as gullible. Third, we should be more stringent in policing epistemic norms, and in empowering, honoring, and rewarding what Nietzsche calls the “police of mistrust.” This is because default trustingness is only rationally justified when such mistrust is systematic and those who do the policing are not wrongly defamed.