'Happiness, then, is the best, noblest, and most pleasant thing in the world.' In the Nicomachean Ethics Aristotle's guiding question is: what is the best thing for a human being? His answer is happiness, but he means, not something we feel, but rather a specially good kind of life. Happiness is made up of activities in which we use the best human capacities, both ones that contribute to our flourishing as members of a community, and ones that allow us to engage in god-like contemplation. Contemporary ethical writings on the role and importance of the moral virtues such as courage and justice have drawn inspiration from this work, which also contains important discussions on responsibility for actions, on the nature of practical reasoning, and on friendship and its role in the best life. This new edition retains and lightly revises David Ross's justly admired translation. It also includes a valuable introduction to this seminal work, and notes designed to elucidate Aristotle's arguments.