You maintain that God's foreknowledge is merely His precognition. The Calvinist maintains that God's foreknowledge is a planning faculty.
You can't prove your position. It is merely a presupposition which you prefer in view of another presupposition which you hold. (That other presupposition is that man's free will is the sovereign determiner of man's destiny.)
Doc, I asked this question of woody recently...last week, perhaps.
I asked if God is ABLE to have a new thought. Woody, I believe, said "yes." What do you think?
The word is proegnw which is basically just "before know" or "foreknow." I don't have my library here yet from Oklahoma, but my memory of the word and of Greek says that the "plannning" aspect you mention is by way of YOUR INTERPRETATION and not by way of any necessary TRANSLATION of the Greek word.
In other words, we're dealing with YOUR presupposition, and you say that I'm dealing with MY presupposition. So be it. Dueling presuppositions.
The "law of God written in their hearts...." actual description of God's activity, or symbolic description? In other words, has God (as a literal interpretation would hold) ACTUALLY carved an inscription on their heart? Or has he done SOMETHING to their hearts, at all?
Do you say he has done NOTHING AT ALL to their hearts? If so, what? If not, then how do you account for these words?