This book is an attempt to recover and restate, in a fresh and relevant way, an ancient vision of the nature of moral theory and of the good life. It defends and elaborates a cognitivist or naturalist account of ethical terms, and a perfectionist account of the good as the noble. It does so in full awareness of the problems raised for such accounts by the still dominant twentieth century philosophical debate. Through a sustained critique of protagonists on both sides of this debate, a careful unraveling of the issues, and a tracing of origins in writers from Hobbes to Kant, the author shows how fertile ancient ideas can be in providing new insights. Facts and values, 'is' and 'ought', supervenience, teleology and science, freedom of choice, justice, friendship, and the good are some of the themes treated in this attempt at comprehensive ethical theorizing. A supplement at the end about historical origins gives a more detailed account of the modern writers from Machiavelli to Kant whose thought still marks and mars contemporary philosophical discussion.