Disdain for Cicero is widespread among contemporary philosophers. This chapter shows this attitude is mistaken. It focuses on three topics where Cicero speaks to contemporary philosophical problems with special urgency and relevance: cosmopolitanism, aging, and friendship. Cicero’s analysis of the duties of justice and the duties of material aid in his De officiis became the foundation for much of modern international law. But his analysis suffers from a bifurcation: it makes the former fully global (national boundaries are irrelevant) and the latter very elastic. The topic of aging has been entirely neglected by philosophers. Cicero’s dialogue De senectute offers a defense of old age against stigma and prejudices: some arguments are unconvincing, but many are excellent and have much to teach us. In his De amicitia, Cicero offers a convincing critique of common self-insulating pictures of friendship and an exploration of friendship as an element of political life, of which Cicero’s long-lived friendship with Atticus is a perfect example.