In preceding chapters, I have considered the nature of loyalty, the principle of loyalty to loyalty, how to learn loyalty, and how to be loyal in the context of community. In this chapter, I focus on disloyalty. While one may be tempted to describe disloyalty as simply the antonym of loyalty, the discussion of the loyal traitor in chapter 5 suggests that distinguishing between loyalty and disloyalty may not be so tidy an affair. I will here focus for some length on the account of disloyalty given recently by Simon Keller, who holds that “it is possible to say what is wrong with disloyalty, when it is wrong, without making a more fundamental commitment to the value of loyalty.”1 While I agree with some aspects of Keller’s account of disloyalty, I conceive of disloyalty as wrong precisely insofar as it negates something we value: loyalty. Thus Keller’s account of disloyalty stands in need of revision. Royce’s treatment of disloyalty aids in this revision. In addition to proposing necessary and sufficient conditions for an act to be characterized as one of disloyalty, the account of disloyalty articulated in this chapter includes phenomenological descriptions of disloyalty as experienced by both the betrayer and the betrayed.