This dissertation argues that in two different genres, oratory and political philosophy, Cicero presents to the Roman elite a variety of possible motives for pursuing a political career, and advances his vision of legitimate political engagement. It challenges recent interpretations, first, by demonstrating how Ciceronian forensic rhetoric transcends judicial goals in pursuit of broader cultural and political aims (Chapter 1); second, by demonstrating that Cicero’s political philosophy advances a new form of elite engagement, informed by Greek ethical philosophy and contemplative pursuits (Chapters 2-4); and, third, by demonstrating that Cicero viewed philosophy as essential for rhetoric, not due to its instrumental value but as an ethical grounding for both personal behavior and public oratory (Chapter 4). The first chapter argues that in the Pro Sestio, Cicero uses the prospect of civic glory to motivate his listeners to defend the republic. The second chapter, in contrast, shows how Cicero’s first dialogue on political philosophy, the De Re Publica, downplays the motive of civic glory in favor of less mercenary motives drawn from Greek ethical philosophy, especially the attraction of virtue as its own reward. Cicero attempts to persuade his potentially resistant Roman audience, however, by adopting an initial pose of hostility towards philosophy and by putting philosophical ideas in the mouths of his Roman dialogical personae. The third chapter, on the Somnium Scipionis, argues that Cicero concludes the De Re Publica by employing the authority of Scipio to inspire his audience to study cosmology in order to acquire knowledge of the motives, ends, and means of political engagement; Scipio qualifies Laelius’s earlier argument about virtue, reevaluating it as a means to an eternal reward based on Platonic eschatology. The fourth chapter shows that in De Legibus 1, the character Marcus Cicero mounts two arguments for natural law in two different styles, one aimed at Atticus the intellectual and the other at Quintus the politician, suggesting two chief segments of his potential reading audience. Marcus concludes with an inspiring speech intended to show Atticus that philosophy demands engagement in politics and to convince Quintus that philosophic knowledge gives public oratory ethical grounding.