We recognize the existence of expertise in many domains, from plumbing to physics, meteorology to medicine. Nor do we think it problematic to defer to the opinion of those who have the expertise we lack in these and other fields. When it comes to morality, however, many have the intuition that deference is problematic. This intuition is supported by reflecting on the oddness of, for example, becoming a vegetarian on the basis of someone telling you that meat eating is wrong, without yourself fully considering the matter. This chapter is an exploration of the asymmetry thesis, or the claim that morality differs from other domains of inquiry (with the possible exception of aesthetics) insofar as deference is problematic in the moral domain in a way that it is not in other domains. The asymmetry thesis can be defended using two broad strategies: 1. Challenge the existence of moral expertise, for justified deference must be deference to expertise not mere authority, so if there is no moral expertise then there should be no moral deference. 2. Identify something distinctive about morality that precludes deference. This chapter examines a variety of attempts to pursue each of these broad strategies, and argues they fail to provide adequate support for the asymmetry thesis.