Thesis advisor: Robert C. Bartlett / This study examines Dante Alighieri's presentation of the relation between Church and State and of their foundations in either the Christian faith or philosophic reason. It seeks to demonstrate how Dante's unmodern acceptance of a teleological understanding of the world and man’s place in it allows him to distinguish the two while also showing how both work together even as they understand differently the role that reason should play in human life. It is because of this distinction that Dante's Monarchia shares in the political principle of “separation” that underlies the secular regimes of the West, thereby making his work immediately accessible to modern-day readers. It is because of the way reason and faith also work together in his political treatise, however, that Dante does not endorse, as readers today would, the further separation of his State from Society. This is because for Dante the very ideas of Church and State not only presuppose the existence of the highest goods of man -namely, that terrestrial good that pertains to man insofar as he is a natural being, and that spiritual good that pertains to man insofar as he is a creature capable of being transfigured by the divine grace of God. They also are intended to embody and publicly promote these two goods. Thus for Dante the Church is meant to help man attain his immortal end, which consists in the supernatural act of seeing God "face to face," while the State is meant to help man attain his mortal end, which consists in grasping philosophic truths. And so it is for these teleological and illiberal reasons that Dante's work remains as inaccessible as it does familiar to readers today. Yet it is by virtue of his refusal to forge our distinctively modern course, and so because of his acceptance of an "outdated" Aristotelian principle of teleology, that Dante's philosophic politics establishes a clearer demarcation between Church and State or reason and faith than modern political philosophies do. His Monarchia is therefore an invaluable guide for all those who wish to acquire a better understanding of the nature and limit of each. This latter claim can prove to be true, however, only if the end of his treatise is understood in light of what many scholars have either ignored or denied in their reading of the Monarchia, and that is Dante’s "Latin Averroism." / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Political Science.