Politics is becoming increasingly polarized. According to research in moral psychology, these growing disagreements between liberals and conservatives can be attributed to fundamental differences in the moral frameworks that shape individual ideology. Indeed, scholars suggest that ideologues would be more likely to reach compromise if both sides spoke the same "moral language." While this implicit assumption has intuitive appeal, it remains largely untested empirically. Drawing on a unique dataset from the online discussion board Reddit, this paper examines how moral appeals can affect individual persuasion and the likelihood of compromise.