This chapter discusses the value of trust through the lens of the work of John Locke. Locke’s treatment of trust is initially puzzling. His political philosophy places a high positive value on trust between government and the governed. His epistemology is extremely dismissive of trust in epistemic authorities. The key to resolving this apparent disunity in Locke’s views, Simpson argues, is to recognize that Locke thinks that the value of trust is instrumental only. Trust between government and the governed is valuable, in Locke’s view, because it promotes a government accountable to its citizens. Epistemic trust, by contrast, has disvalue because it discourages autonomous thought. Securing the conditions for individual autonomy is Locke’s overarching aim, and his evaluation of trust depends on how effectively it promotes that. Although Locke’s view is coherent, given the premise that the only value to trust is instrumental, Simpson rejects this premise, arguing that trust has intrinsic value, whether in politics or epistemology.