This book is about happiness and about how the supremely happy life - the life blessed with what Aristotle refers to as eudaimonia - is the life of an ethical individual living in a healthy community. Much ethical literature has drawn inspiration from Aristotle's outlook, but relatively little attention has been paid to the central concept of Aristotle's ethical system - the concept of eudaimonia. This book fills this important gap, focusing on Aristotle's central ethical concept and, among other things, using Davidson's account of mind and rationality to explain central Aristotelian claims relating to the structure of the psychological domain and to our radical interconnectedness. Starting with Aristotle, Tabensky shows how the ethical domain can best be understood in relation to our fundamental desire to live happy lives. Recapturing the Greek spirit, this book is an invitation to rethink the manner in which we understand our lives and the manner in which we conduct ourselves, and it is an invitation to do so in relation to an understanding of the sorts of creatures we are - creatures living for the sake of happiness.