//For a being to claim to know a proposition is true presupposes that he knows it's truth is not contingent or, if it is, said being knows that upon which the veracity of the proposition is contingent. Let's call this being Ryan. This implies two things:
1. Ryan is omniscient or has acquired his knowledge from a being who is omniscient, as Ryan would be required to know the relation between a proposition and anything upon which the veracity of the proposition might be predicated (which in turn implies knowledge of everything, including respective contingencies).
2. Ryan's knowledge is infinite or has acquired his knowledge from a being whose knowledge is infinite, as there are infinitely many possible relations one might posit between the proposition in question and everything imaginable.//
The thought that occurred to me was that not only is man's knowledge dependent upon an omniscient, infinitely knowledgeable being, but said being cannot have become omniscient or infinitely knowledgeable through a process; that is, it is necessary that the being in question is eternally omniscient. For simplicity, let's call this being God and let "eternal omniscience" encompass the notion of infinite knowledge.
Now God, if He is not eternally omniscient, must, if one is to allege that He has or can become omniscient, have at some point learned that which He did not know. In other words, God was not omniscient prior to having learned that which He did not know. So far, so obvious.
But if this is so, it would not have been possible for God to know the relation between that which, prior to His learning, God did not know and everything else imaginable. Given this, however, God would have been in the same boat as man! Again, from the aforementioned post:
//Or we may consider these questions: how does Ryan know the proposition he claims is true isn't contingent on x, y, or z? If Ryan doesn't know, can he justifiably claim to know the proposition is true? No.//
Or: how would God have known any proposition He claimed is true isn't contingent on that which He did not know? He couldn't, precisely because He can't know any relation between that which He does not know and everything else imaginable until He actually knows the unknown proposition. This in turn implies God either wouldn't know anything unless He knows everything from eternity or that He has, like men, acquired His knowledge from one who is (but in this case, He from whom God would have acquired His knowledge would actually be "God" in the traditional sense).
The implications of this thought appear deep: for instance, predicating God's knowledge on that which is extrinsic to God would, since God alone is eternal, not only destroy God's omniscience, it destroys God's knowledge, period. It refutes Open Theism outright, and it is yet another weapon in the Christian's arsenal of elenctic arguments for which secular philosophy cannot answer.
[I've tried to make this post as short as possible even though I think I could make the thought contained herein clearer, because I wanted to put the point as simply as possible before I forgot it.]
P. S. Should anyone ask how I know that this argument is self-affirming, I'd point him to the Bible..