This chapter shows how Roman philosophy make of Aristotle's ethical writings and teachings, and examines the role of Aristotle's ethics in the most active period of Classical Roman philosophical culture, the first centuries BC and AD. The three topics (emotions, development, happiness) considered in the chapter are interlocked and constitute subjects of active debate in the post-Hellenistic period. As regards emotions, there are two interconnected themes, the ideal characteristic and the psychological assumptions linked with the relevant ideal. Development toward virtue is taken to depend on a combination of a specific kind of inborn nature, social habituation and rational education. Aristotle's ideas were influential in promoting a specific type of framework for ethical theory, in which happiness (eudaimonia) was treated as the overall goal (telos) and virtue was a key (or the key) constituent of happiness.