The paper is organized as follows: In Section 8.2, I characterize varieties of disagreement as well as the notion of epistemic peerhood. In Section 8.3, I consider a broad argument to the effect that disagreement may defeat or diminish epistemic warrant: The Argument from Self-Doubt. In Section 8.4, I argue that this negative impact of disagreement is more severe than is commonly recognized once we consider the effects of the disagreement at the level of the social group. In Section 8.5, I indicate how the noted epistemological problems with disagreement may breed epistemic injustice in the community. Finally, in Section 8.6, I briefly consider what measures a community may take in order to avoid the noted epistemological problems with disagreement.