From Ask an Open Theist (Greg Boyd)…Response:

From Sonja: So if I’m understanding open theism right, it sounds like it’s similar to–if not the same as–the idea that “omniscience” in God doesn’t mean “knows exactly what will happen” but instead means “knows every single permutation of what could happen.” Is that far off?

Greg. No, it’s not off at all! You’re actually stating a philosophical truth that I believe is extremely important. The next few paragraphs might be a little heavy for some readers because I have to use a little bit of philosophical jargon. But its Sonja’s fault because she asked such an important question! I encourage you to hang in there because I believe the point I’ll be making hits on one of the most fundamental mistakes made in the church tradition regarding the nature of omniscience and offers one of the strongest philosophical arguments for the open view:

Philosophers and theologians have often defined “divine omniscience” as “God’s knowledge of the truth value of all meaningful propositions.” I completely agree with this. Unfortunately, they typically assumed that propositions about what “will” and “will not” occur exhaust the field of meaningful propositions about the future. They thus concluded that God eternal knows all that will and will not take place and that there is nothing else for God to know.

This is a mistake, however, because propositions about what “might and might not” take place are also meaningful, and God must therefore know the truth value of these. Moreover, the opposite of “might” is “will not,” and the opposite of “might not” is “will.” So, if a “might and might not” proposition is true, then the corresponding propositions about what “will” and “will not” take place are both false.

For example, if its true that “Greg might and might not buy a blue Honda in 2016,” then its false that “Greg will (certainly) buy a blue Honda in 2016” and false that “Greg will (certainly) not buy a blue Honda in 2016.” So too, if it ever becomes true that “Greg will (certainly) buy a blue Honda in 2016” or true that “Greg will (certainly) not buy a blue Honda in 2016,” then it will be false that “Greg might and might not buy a blue Honda in 2016.” And since God knows the truth value of all propositions, God would know precisely when it is true that I “might and might not” buy this car and when it becomes true that I either “will” or “will not.” God thus faces a partly open future.

The irony is that, while open theists are constantly accused of limiting God’s knowledge, if my analysis is correct, it was the classical tradition that limited God’s knowledge! They overlooked an entire class of propositions the truth value of which an omniscient God must know. And it was right under their noses, for as I just demonstrated, the truth value of “might and might not” propositions is logically entailed by the true value of “will” and “will not” propositions. Hence, if God knows the truth value of “will” and “will not,” he must also know the truth value of “might and might not” propositions.