Molinism is the basic theology formulated by Jesuit theologian Luis De Molina.1 Molina taught that God's knowledge can be divided into 3 "logical moments". Natural, middle, and free.
God's Natural Knowledge is His knowledge of everything that could happen in any given circumstance. It's His knowledge of all the free choices any creature could make in any given circumstance. It also is His knowledge of all necessary truths such as 1 + 1 = 2.
God's Middle Knowledge is His knowledge of everything that would happen in any given circumstance. It's His knowledge of what any free creature would freely choose in any given circumstance. For example, God knows "If Evan Minton were given $2,000 worth of Kindle gift cards, he would freely choose to download all of the books on his GoodReads 'to-read' list", or "If Bob went to Tatsuki's Japanese Restaurant, he would freely choose to order sushi".
God had these two logical moments of knowledge logically prior2 to His decision to create any world. Logically prior to His decision to create the universe, God knew everything that could happen in any given circumstance and everything that would happen in any given circumstance.
God's Free Knowledge is His knowledge of everything that actually will happen. Free knowledge is synonymous with foreknowledge. This knowledge is the knowledge of all future events. The content of God's free knowledge is a result of the sovereign choice of God to actualize one of the worlds God knew about in His middle knowledge.
On Molinism, Everything happens because God decreed it, yet all of our choices are free. All Molinists agree on these facts. This is "Mere Molinism".
Let's take the crucifixion of Jesus as an example. The Bible says "This man [Jesus] was handed over to you by God's deliberate plan and foreknowledge; and you, with the help of wicked men, put him to death by nailing him to the cross." (Acts 2:23, emphasis mine). The crucifixion of Jesus was deliberately planned by God, His foreknowledge played a role in the matter, but it was wicked men who put Jesus to the cross. Molinists say that God knew that if Caiaphas was high priest in the first century, then he would freely condemn Jesus on grounds of blasphemy and he would freely take Him to Pilate for execution. He knew that if Pilate was prefect in the first century, then he would freely comply with the demands of the crowd. And God knew that if Judas was born in the time and place that he actually was, then he would become Je