As form of rule, tyranny is broadly understood to consist of institutional deficits that leave a ruling party or actor unaccountable and unconstrained. As a figure in the history of political thought, the tyrant is characterized by his ethical immoderation and desire for gain. While scholars rightly identify Aristotle as a foundational theorist for this picture of tyranny and tyrant, I argue that they overlook the centrality Aristotle assigns to tyranny’s guarded orientation to power, as well as the tyrant’s anxieties regarding its potential loss. Taking as its point of departure Aristotle’s claim in Rhetoric 1.8 that the end or goal (telos) of tyranny is self-preservation (phulakē), this dissertation illuminates the ethical and political conditions, constraints, and pressures that characterize the Aristotelian tyrant’s defensiveness. Ruling over a regime populated by those whose sense of justice bristles at his disproportionate share of power, the Aristotelian tyrant, I argue, is driven by fear.