Abstract Because moral understanding involves a distinctly first-personal grasp of moral matters, there is a temptation to think of its value primarily in terms of achievements that reflect well on its possessor: the moral worth of one's action or the virtue of one's character. These explanations, I argue, do not do full justice to the importance of moral understanding in our moral lives. Of equal importance is the value of moral understanding in our relations with other moral agents. In particular, I argue that an understanding of moral matters is of central importance within relations of solidarity. In addition to highlighting an overlooked aspect of moral understanding's value, this view also has important implications for what solidarity requires of those who stand in that relationship.