What kind of knowledge is Middle Knowledge, actually? At best, it could only be analytical and theoretical, because it is never instantiated, never incarnated (apart from that which becomes Free Knowledge). What isn't actualized is merely hypothetical--a mental "trial run," if you will. Supposedly, Middle Knowledge answers with certainty, not mere conjecture, the question: "What would occur if another state were to obtain? Since those other states are nothing more than whimsy in the mind of God, who purposely selects what is actualized, how is the outcome resultant from using Middle Knowledge distinct from, or better than, compatibilism (soft determinism)?
A Bible passage that purportedly backs this premise is Christ's musings concerning Sodom and Gomorrah. I question whether or not interpreting the passage to teach Middle Knowledge catches the gist of what Jesus was using the illustration for.
“Woe to you, Chorazin! Woe to you, Bethsaida! For if the miracles that were performed in you had been performed in Tyre and Sidon, they would have repented long ago in sackcloth and ashes. But I tell you, it will be more bearable for Tyre and Sidon on the day of judgment than for you. And you, Capernaum, will you be lifted to the heavens? No, you will go down to Hades. For if the miracles that were performed in you had been performed in Sodom, it would have remained to this day." Matthew 11:21-23 NASBWas Jesus divulging precise alternate history or just making a point about how awful was the rejection of Christ by Jews who heard what he said and saw what he did? I don't think there's really much of a question.
If God can forecast the free choices agents would make in any circumstance accurately, without fail, prior to anything created existing, then I submit that those actions are not truly the agents' at all, but are instead mere projections of the mind of God. How could they be proven to be otherwise? The only qualification that withstands scrutiny and averts blameworthiness when it comes to matters of choice is independence (in connection to this, see Genesis 2:19; Judges 3:4; Jeremiah 19:5; James 1:13-15). Choice has to be made by the chooser and seen by the seer at the moment of decision in order to be free.
If a decision of an agent is known with absolute certainty before anything else was even made, and if in making everything else God opts among various possibilities to instantiate that decision (the agent certainly has no access to those possibilities), God unavoidably becomes the author of that decision. There is no way that choice is free in the sense that it is instigated in freedom by the chooser. The biblical notion of freedom, as I see it, is that choice is derived independently of God. If that choice "happens" before it happens, the choice is illusory.
Middle Knowledge was formulated as a means of attributing meticulous sovereignty and foreknowledge to God without obliterating freewill or having God incur culpability for actions taken which he opposes (sin). It fails to do so. If God knew what every choice an agent would make was before he created the universe, and knowing, then actualized that "blueprint," then culpability for all choices (including sin) adheres unshakably to God, and none of those choices are actually free (independent).
Molinism, it seems to me, reduces to determinism, so why add the extra layer?