 In other words, Dante’s argument in De vulgari eloquentia ultimately depends upon and reinforces the claims of the Convivio that just rule requires the unification of philosophical authority with that of the authority to establish and enforce laws. Philosophy qua philosophy is impotent in the task of guiding all but those who have already achieved both ethical and intellectual virtues. The emperor, on the other hand, can indeed either benefit or corrupt his subjects, but the emperor’s legitimacy depends on his recognition of the priority of philosophy’s claims to the knowledge of the principles of justice and the other human virtues since such matters are dictated more by human nature than by local conventions. What the De vulgari eloquentia adds to Dante’s emerging political philosophy in the Convivio, however, is explicit attention to the significance of poetic/rhetorical discourse as a tool to be used on behalf of the project of unifying people under the joint rule of philosophy and empire—a perspective that it is easy to imagine played a significant role in his choice to turn back to poetry as his primary vehicle for addressing his fellow Italians in their own vernacular in the Divine Comedy.