How is it that St. Thomas's natural law teaching accords with Aristotle's teaching in the Ethics, and how does it differ?
Secondarily, to what extent do you think Aristotle would agree with the presentation that we see in Thomas's work?
There is one obvious disagreement: Aristotle would not speak of natural law, because law requires a lawgiver, and Aristotle has no conception of a personal, legislating God such as the God of the Abrahamic faiths. Is that the only difference, however? Or do you see more?
Also read Philipa Foote's essay in the text (Chapter 8, section 6: "Virtues and Vices"): what differences do you see between her approach and Aristotle's approach in the excerpts from the Ethics?