One point which he should have made is the connection between St. Thomas' conception of ethics and natural law and his conception of metaphysics.
Thomas adopts Aristotle's fundamental principle that "the good is that at which all things aim" and shows its affinity to God's commandment to Israel "I have set before you life and death, good and evil, blessing and curse: choose you therefore life" and formulates his own first principle of the natural law: "that good is to be done and pursued and evil avoided".
And St. Thomas defines good as "convertible with being" - that good actions are actions which enable man to "be" more fully. For St. Thomas only one being truly is in the fullest sense - God. So the natural law - doing good and avoiding evil - is to strive to imitate God in His being, His goodness. For St. Thomas there is no conflict between natural law and divine law - Christ became man in order to show us how natural law may most perfectly be fulfilled and He died to give us the grace to follow that perfection - so that we may have "life, and have it more abundantly".