(3) assumes that one knows that p only if one can truly token “p” to oneself. Aquinas seems to have questioned this.  He reports “ancient nominalists” as dealing with (1)–(4) by denying (3) — they claimed that what God knows is simply an event, the nativity of Christ, and so the sentences “Christ was born” and “Christ will be born” signify the same thing, since they signify the same event (ST Ia 14, 15 ad 3), and therefore the objects of divine knowledge these sentences express do not differ.  Aquinas objects that the differences in the sentences cause them to express different propositions, and so concedes that it is not true that whatever proposition ever expresses what God knows, always expresses what God knows.  This, however, does not mean that God's knowledge itself changes, Thomas adds, because He does not know what He knows by affirming propositions (ibid.). Rather, His knowledge is a timeless intuition which shows that propositions are at one time true and another false (ibid. et De Ver. 2, 5 ad 11; for commentary see Sullivan 1991). Aquinas, then, might simply deny the tokening requirement, and so (3): he may object not to the nominalist move, but to how they get there.