Can Moral Perfection be an Essential Attribute?

Some of these philosophers in centuries past have spoken of the goodness of God, have regarded goodness as one of his essential properties, and have held that it is therefore impossible that God do anything that is inconsistent with his goodness.z During the last two centuries theists have spoken of the moral perfection of God, and have also regarded it as one of his essential properties, from which it follows that it is impossible that God fails to do anything that he ought to do.3 A recent example of such an attribution is found in Alvin Plantinga's The Nature of Necessity, in which he presents an argument which entails not only that there is an individual that has the attribute of necessary existence but also that it is essentially omnipotent, essentially omniscient, and essentially morally perfect.4 I have argued elsewhere that the idea embodied in (E) is mistaken precisely because at least one of the four attributes just signified cannot belong to God that, in fact, nothing can possess all four.' That argument did not presuppose any particular conception of morality. Here I want to argue that, regardless of what is true of the others, God cannot possess the attribute of essential moral perfection, if we use 'moral' in its