This chapter discusses Cicero’s views on the relation between ethical theory and the good human life, focusing on his main work on ethical theory, De finibus. Cicero’s critique of Stoic and Epicurean ethics has a common element, all the more striking given the differences between the two doctrines, namely that neither theory is livable with integrity in social contexts. This critique is a reflection both of Cicero’s belief that ethics should engage with lived human experience and of the commitment, in varying degrees, of the Stoics and Epicureans to a conception of the good human life as inherently social. The pluralism of the Old Academy’s ethics discussed in the final part of De finibus escapes this critique but is in danger, through lack of a single supreme value, of failing to offer a basis on which we may structure our lives. Taken as a whole, De finibus can thus be seen to cast a skeptical eye on the viability of ethical theory itself.