Epistemologists have distinguished mere knowledge from understanding. When one understands a proposition, one has a deeper grasp of its truth. This same distinction applies in the moral domain. One can merely know a moral proposition, for instance through testimony, without really having a deep understanding of it. My dissertation defends an affective account of moral understanding. Using phenomenological considerations, I first argue that emotional experiences allow us to grasp, and thus understand, moral propositions about specific acts and individuals. I then argue that emotional dispositions are the essence of understanding general moral principles. This account avoids problems with inferentialist accounts and also explains why certain moral propositions seem to defy human comprehension.