In Ancient Greek thought, a concern for ethical perfection was often expressed. Two prominent voices in present day discourses on ethics are Plato and John Chrysostom. In his Republic, Plato conceptualizes the ideal city where justice, or ethical perfection, prevails. Likewise, Chrysostom in his Against the Opponents of the Monastic Life describes the life of the monastic community, wherein ethical perfection also seems to be the goal. Nevertheless, despite these striking parallels, David Rylaarsdam’s John Chrysostom on Divine Pedagogy laments the tendency in modern scholarship to categorize Chrysostom as a moralist, differing from Plato perhaps only in his Christian faith. Both figures are clearly concerned with ethical dogmata and their subsequent effects upon all aspects of the human person and life. However, the concern for ethics alone does not necessarily justify the characterization of moralist. Therefore, as it has been questioned whether both can rightly be identified as moralists, the present paper investigates the ethical concerns of each, through a comparison of Plato's Republic with Chrysostom's Against the Opponents of the Monastic Life, in order to discern the sources from which these concerns originate, and the purposes to which they are directed.