Many people are inclined to think that if God is omniscient, then human beings are never free. Why? Because the idea that God is omniscient implies that at any given time God knows not only what has taken place and what is taking place, but also what will take place. He knows the future as well as the past. But now suppose He knows that Paul will perform some trivial action tomorrow - having an orange for lunch, let's say. If God knows in advance that Paul will have an orange for lunch tomorrow, then it must be the case that he'll have an orange tomorrow; and if it must be the case that Paul will have an orange tomorrow, then it isn't possible that Paul will refrain from so doing - in which case he won't be free to refrain, and hence, won't be free with respect to the action of taking the orange. So if God knows in advance that a person will perform a certain action A, then that person isn't free with respect to that action. But if God is omniscient, then for any person and any action he performs, God knew in advance that he'd perform that action. So if God is omniscient, no one ever performs any free actions.END
This argument may initially sound plausible, but the fact is it is based upon confusion. The central portion can be stated as follows:(49) If God knows in advance that X will do A, then it must be the case that X will do A.and(50) If it must be the case that X will do A, then X is not free to refrain from A.From (49) and (50) it follows that if God knows in advance that someone will take a certain action, then that person isn't free with respect to that action. But (49) bears further inspection. Why should we think it's true? Because, we shall be told, if God knows that X will do A, it logically follows that X will do A; it's necessary that if God knows that p, then p is true. But this defense of (49) suggests that the latter is ambiguous; it may mean either(49a) Necessarily, if God knows in advance that X will do A, then indeed X will do Aor(49b) If God knows in advance that X will do A, then it is necessary that X will do A.The atheological argument requires the truth of (49b); but the above defense of (49) supports only (49a), not (49b). It is indeed necessarily true that if God (or anyone else) knows that a proposition P is true, then P is true; but it simply doesn't follow that if God knows P, then P is necessarily true. If I know that Henry is a bachelor, then Henry is a bachelor is a necessary truth; it does not follow that if I know that Henry is a bachelor, then it is necessarily true that he is. I know that Henry is a bachelor: what follows is only that Henry is married is false; it doesn't follow that it is necessarily false.
So the claim that divine omniscience is incompatible with human freedom seems to be based upon confusion.
(God, Freedom, and Evil, New York: Harper Torchbooks, 1974, 66-67)
Tuesday, November 07, 2006
Foreknowledge and Omniscience Do Not Require Determinism Or Elimination of Human Free Will (Alvin Plantinga)
I wish I had a dollar for how many times this issue has come up. My usual quick reply to this fallacy is saying, "I have pretty certain knowledge that the sun will come up tomorrow, but that doesn't mean that I caused it to come up. " I found a far more interesting treatment from Christian philosopher Alvin Plantinga: