An Argument Against Open Theism

Open Theism is the view that, among other things, God lacks foreknowledge of the future. This is certainly in contradiction to the orthodox Christian view of God’s omniscience that is presented in Sacred Scripture (cf. 1 Samuel 23:9-14, Psalm 139:1-6, Acts 2:22-23; 4:27-28). It is also contrary to the solemn teaching of the Catholic Church as formally defined, for instance, by Vatican I: "All things are open and laid bare to his eyes [Heb. 4:13], even those things that will be done by the free actions of creatures" (Fundamentals of Catholic Dogma, pg. 44). Ludwig Ott assigns the theological note of de fide to this doctrine. I have formulated the following argument against Open Theism that I think is interesting and persuasive. Note that a proposition is contingent if its truth value is not necessary. The argument focuses on contingent, future tense propositions because these are the propositions of most interest in the discussion on Open Theism. Open theists do not take issue with, for instance, God knowing the proposition “tomorrow, it will be the case that 2 + 2 = 4.” This is a necessary proposition in contrast to a contingent proposition like “tomorrow, there will be a sea battle.” It is knowledge of propositions like these that open theists deny to God.

1. Future tense, contingent propositions have no truth values, or they are uniformly false, or they are uniformly true, or they are variously true or false and correspond to the reality of what will happen in the future.
2. It can’t be the case that future tense, contingent propositions have no truth values (because then tautologies like “there will or will not be a sea battle tomorrow” couldn’t be true, and they are true).
3. It can’t be the case that future tense, contingent propositions are uniformly false (because then contradictions could be derived like “it is false that there will be a sea battle tomorrow and it is false that there will not be a sea battle tomorrow”).
4. It can’t be the case that future tense, contingent propositions are uniformly true (because then contradictions could be derived like “it is true that there will be a sea battle tomorrow and it is true that there will not be a sea battle tomorrow”).
5. Therefore, future tense, contingent propositions are variously true or false and correspond to the reality of what will happen in the future (1, 2, 3, 4).
6. If future tense, contingent propositions are variously true or false and correspond to the reality of what will happen in the future, then there are contingent facts about the future.
7. Therefore, there are contingent facts about the future (5, 6).
8. If God is omniscient, then He knows all facts.
9. God is omniscient.
10. Therefore, God knows all facts (8, 9).
11. Therefore, God knows the contingent facts about the future (7, 10).
12. If God knows the contingent facts about the future, then God has foreknowledge.
13. Therefore, God has foreknowledge (11, 12).
14. If God has foreknowledge, then Open Theism is false.
15. Therefore, Open Theism is false (13, 14).

If I were an open theist, I would probably try to attack (8) and suggest redefining omniscience in terms of what it is possible to know and insist that it is impossible to know future contingent facts even if there are future contingent facts. How this redefinition of omniscience would do justice to our pre-philosophical intuition of what omniscience is remains, by my reckoning, an open problem for the open theist. So, I suggest we stick to biblical (and Catholic) orthodoxy.  :)

“For, to confess that God exists, and at the same time to deny that He has foreknowledge of future things, is the most manifest folly” (St. Augustine, The City of God, Bk. V, Ch. 9).