MacIntyre's now classic history of moral theory was written in the highly individualistic years of the mid-late sixties. Today, MacIntyre is regarded as one of the world's most significant moral philosophers, but when he wrote this book, few outside of the discipline had ever heard of him. No doubt, the book reflects MacIntyre's strong opinions, but they are well-considered, deeply thought, and generally well-argued. Further, the nature of the project keeps MacIntyre in the mainstream of his subject, and the book provides an extremely comprehensive and relatively concise (270 pages) survey of the peaks in the development of western moral theory (which, despite the many claims of post-modern pundits, is still at the heart of the philosophic project as a whole). A number of MacIntyre's arguments show a fascinating and appropriate application of Wittgenstein's ideas, which, at the time of this writing, still basked in the glow of the apotheosis they had undergone in the 1950's.
MacIntyre is strong on the Greeks. His sections on Socrates, Plato, and Aristotle, and the development of Greek moral thought fill the first 100 pages. Socrates' basic teachings are examined, and while MacIntyre is a bit too materialistic to really "get" Plato, he details the main strokes well, in a fairly thorough discussion of The Republic. His examination of Aristotle's moral theory is enlightening, one of the best available in brief.
The middle of the book deftly deals with the impact of Christian moral thought (see Max Weber for more), the development of early modernity (good on Hobbes; interesting on Spinoza), further developments in 18th century France and Britain (if you've ever wanted to know how the ideas of Locke, Mandeville, Shaftesbury, Hutchinson, Bishop Butler, Paley, Price, Reed, and Hume, et al. fit together in less than ten pages, look no further). Hume is discussed more deeply in other books of this sort (see Norman "The Moral Philosophers"). The discussion is followed by excellent summaries of Montesquieu and Rousseau. (For some reason Montaigne is ignored along with the rest of late 16th and early 17th century French thought).
Then comes what, in my opinion, is the gem of the book, his analysis of Kant. The final claim in the chapter, that the arbitrary nature ("the logical emptiness") of Kant's categorical imperative ironically did far more than any other philosophic claims to prepare the German psyche to rationalize the acceptance of totalitarian National Socialism, albeit controversial, deserves careful perusal.
The final third of the book includes informative sections on Hegel, Marx, Kierkegaard, Nietzsche (R. Soloman and K. Higgins are better in the brief style format on Nietzsche), Utilitarianism (R. Norman is stronger on Mill, but MacIntyre is sfficient) and ends about halfway through the 20th century, mostly discussing developments in British moral philosophy (Moore, et al). There's a few pages on Sarte (not nearly enough), Dewey, and less known figures such as Stevenson. All in all, better buy a seperate book which deals with this turbulant century all by itself. MacIntyre, however, provides enough of an intro.
The book is excellent in showing the interrelation and development of the most stimulating ideas which have arisen in Europe over two-and a-half thousand years in regard to how we ought to live, how we do, and the whys and wherefores of most of what matters most in philosophy.