Dr. Eugene Scott said, "God's knowledge is a function of his power. He can know whatever he wants to know." Is this coherent? I thought this was a noncontroversial statement, but I was told it implies that God doesn't know some things because he doesn't want to and therefore is not omniscient. What concepts or factors would a philosopher consider when evaluating this assertion? I am definitely not a trained philosopher and I hope to pick up some basics from the answers.
Although the knowledge-power-goodness characterization of God is often given directly, the deeper one goes in the history of theology, the more one finds attempts to collapse those three either to one of them, or to a rather different characterization from which such predicates are derived. Anselm spoke of a greatest or maximal being; Aquinas worked from a version of divine simplicity (though simplicity is sometimes traced back to aseity or unity) while Scotus worked from "divine infinity" (an evocative phrase). Or Kant, taking the possibility of God as a postulate of moral hope, started with divine goodness ("holiness as substance" was one of his more poetic framings).
So, one could start from omnipotence and say, "God uses Its power over everything else to know everything else," and, "God omnipotently decides to be the greatest good," etc. Now, if we do qualify such statements with reference to what God "wants," then unless we say that God wants to know all and do what's best, we would be minded to say that God "might" not be all-knowing or all-good, here. This isn't an issue of coherence directly, though; and we even might start from two predicates to get the third anyway (e.g. start with an all-good, almighty deity, then say that knowing everything would be good, so this deity will then know everything).