Over at Prosblogion, there's an interesting illustration of the concept of middle knowledge using the Spirit of Christmas Yet to Come. I'm still unconvinced that middle knowledge bridges the fate/foreknowledge gap, allowing for compatibilism. If you tell me that "this is what will come to pass if you choose option X," you haven't cleared up the basic problem of foreknowledge. An "if" conditional is a hedge. The "if" quite clearly indicates lack of specific knowledge about the future. If it's merely all possible future events that are apparent to the omniscient being, then the omniscient being isn't omniscient in the required theological sense of knowing-- definitely-- all actual future events down to the minutest detail.
The proponent of middle knowledge has to reckon with the fact that most nonscholarly classical theists assert some form of the following: "God knows the future. He knows exactly what you'll do five minutes from now." This formulation is what doubters* find problematic. A proponent of middle knowledge is suggesting an entirely different theology: God's knowledge is limited merely to knowledge of possibilities, because God's being is not beyond time. God is right here, with us, staring into the future, but with an infinitely better idea of the possibilities ahead. This is nothing like what the classical theist is saying. The classical theist is saying the future is totally known to God, because God is beyond time and space, such that past, present, and future are all equally visible to God in an eternal Now. There's no question of possibility. The future is already actual to God. The word "future" is merely a human designation for one aspect of God's Now.**
We can frame the issue by asking a simple, clear-cut, yes/no question, to wit:
Middle Knowledge God says, "I know what will happen in five minutes if you take path X. I know what will happen in five minutes if you take path Y." So: does Middle Knowledge God know exactly what will happen to the person in five minutes?
In my view, middle knowledge fails on two levels: (1) it fails to avoid the problem of divine omniscience, and (2) it fails to reflect most normal folks' concept of divine foreknowledge. Failure #2 might not be a problem if more people come to accept a middle-knowledge theology.*** But if middle knowledge is being offered as a plausible classical theistic explanation for how God can know the future, the fact is that it isn't widely accepted among classical theists. Not where it counts, anyway: in the pews, among the laity.
Scrooge should have asked the ghost point-blank: "What is my actual future?"
*By "doubters" I mean people who don't subscribe to classical theism-- atheists, nontheists, the "differently theistic," agnostics, etc.
**Of course, the traditional theist also wants to assert (unless he's a strict Calvinist) that people act freely. Many such theists are aware of and comfortable with this paradox. For them, the problem elicits no more than a shrug. Who can fathom the mind of God?
***Also note that process theologians tend to conceive of God in a manner consistent with middle-knowledge thinking: God is riding the timestream with us, sharing a past and a present; but he is constrained, as we are, merely to peer into the as-yet-unrealized future. The crucial difference between us and God is the acuity of God's vision of the future.