I bought Alistair MacIntyre's A Short History of Ethics a couple of years ago and have only just rescued it from the unread pile. Virtue Ethics is a slippery subject, but MacIntyre's making it clearer to me. As far as I can see (having only read the chapters on Greek philosophy so far), it boils down to rejecting Plato's view in The Republic of The Good as a separate quality, in favour of the more traditional Greek view of good as an evaluation of the fitness of something - it's conformance to a standard. MacIntyre gives the example of "a red book" - Plato's explanation of Good is that it's like redness, so you can say "there's a red thing here" and "there's a book here" - on Plato's account, "a good book" is a book which also has the quality of goodness. The other way of looking at it is that it's more like saying "a good footballer" - someone who is very competent at a skill, not a footballer who has the separate quality of goodness. So "a good book" would be a book which measures up well against the standard by which books are judged, and "goodness" is inseperable from the context in which it's being judged. (Links to moral relativism?)

I'm not sure that's clear, either here or in my mind. I probably need to re-read those chapters!