This course introduces some of the fundamental ethical questions raised by Greek and Roman philosophers and considers how their answers to these questions can help us solve the social, political, and environmental problems we face today. We will cover questions like "what makes a good friend?", "would I be happier if I had more money?", "do I have a responsibility to protect the natural world?", and "how can I make myself a better person?". We will explore a number of ancient ethical theories that emerged in response to these problems, such as the Hedonism of Epicurus, the Intellectualism of the Socrates and the Stoics, and the Primitivism of the Cynics, and we will consider how these theories can be applied in the contemporary world. All readings will be in English; no knowledge of any ancient languages is required.