Being and Goodness
ELEONORE STUMP & NORMAN KRETZMANN
Parts of Aquina's moral philosophy, particularly his treatments of the virtues and of natural law, are sometimes taken into account in contemporary discussions, but the unusual ethical naturalism that underlies all of his moral philosophy has been neglected. Consequently, the unity of his ethical theory and its basis in his metaphysics are not so well known as they should be, and even the familiar parts of the theory are sometimes misunderstood.
We think Aquina's naturalism is a kind of moral realism that deserves serious reconsideration. It supplies for his virtue-centered morality the sort of metaethical foundation that recent virtue-centered morality has been criticized for lacking. 1 Moreover, it complements Aquina's Aristotelian emphasis on rationality as a moral standard by supplying a method of determining degrees of rationality. And when Aquina's naturalism is combined with his account of God as absolutely simple, it effects a connection between morality and theology that offers an attractive alternative to divine-command morality, construing morality not merely as a dictate of God's will but as an expression of his nature. 2 Finally, Aquina's brand of naturalism illuminates a side of the problem of evil that has been overlooked, raising the question whether recent defenses against the problem are compatible with the doctrine of God's goodness.
Aquina's ethics is embedded in his metaphysics, only the absolutely indispensable features of which can be summarized here. Consequently, we can't undertake to argue fully for his ethical theory in this essay. For our purposes it will be enough to expound the theory, to consider some of the objections it gives rise to, and to point out some of the advantages it offers for dealing with recognized issues in ethics and philosophy of religion.