In book I, chapter 39, Aquinas argues that “there cannot be evil in God” (in Deo non potest esse malum). Atheists like Law must face the fact that, if the words are to retain any sense, “God” simply cannot be “evil”. As my comments in the thread at Feser’s blog aimed to show, despite how much he mocks “the privation theory of evil,” Law himself cannot escape its logic: his entire argument requires that the world ought to appear less evil if it is to be taken as evidence of a good God. Even though he spurns the idea that evil is a privation of good, his account of an evil world is parasitic on a good ideal; this is no surprise, though, since all evil is parasitic on good (SCG I, 11). Based on the conclusions of several preceding chapters, Aquinas contends that ”God is goodness, and not simply good [Deus autem est bonitas, non solum bonus]. There cannot, therefore, be any non-goodness in Him. Thus, there cannot possibly be evil in God.” He adds that
“since God is His own being, nothing can be said of Him by participation…. If, then, evil is said of God, it will not be said by participation, but essentially. But evil cannot be so said of anything as to be its essence, for it would lose its being, which is a good (Sic autem malum de nullo dici potest ut sit essentia alicuius: ei enim esse deficeret, quod bonum est)….”This exposes one of the other key defects of Law’s notion of an evil God: insofar as that “god” would be the cause of all lesser evils, it would be the most evil thing, but the more evil a thing is, the less substantial, the less existent it is, and thus the less potent it is. If Law wants to take seriously the theological terms which he’s trying to hoist by their own petard, he would have to agree that a maximally evil god is not only ontologically incoherent, but also the worst possible candidate for being The Creator of All (though I am anticipating the upcoming argument). God could not be essentially evil, and thus could not be the exemplary evil which grounds the evil of all created things. As we already knew, Law is just blowing smoke.