for God to determine at the moment of creation all future human actions and still provide
for humans to be free to act otherwise than God has ordained for them to act. If God
determined before you were born that on a certain day in the future you will do X, then
when that day comes it won't be in your power to refrain from doing X. For if it were, it
would be in your power on that day to prevent an event (your doing X) from occurring
that God long ago decreed to occur on that day. And no one seriously thinks that
creatures enjoy that degree of power over God's eternal decrees. So, however it is that
God knows from eternity our future free actions, actions we bring about but have the
power not to bring about, it cannot be that he knows them because he has decreed from
eternity that we should perform those actions. Should we then say that God's knowledge
of our future actions derives from his determining decrees, but that our future actions are
not performed freely? Although that position has the virtue of consistency, it deprives
God's creatures of moral responsibility for their actions, since they lack the power not to
perform those actions. So, however it is that God knows in advance what we will freely
do, his knowledge cannot be based on his predetermining decrees.
It may seem that the only problem concerning divine foreknowledge and human freedom
concerns the source of God's foreknowledge of human free acts. But there is an equally
serious problem concerning whether divine foreknowledge itself—whatever its source
may be—is consistent with human freedom. We can see what this problem is by
considering the following argument:
- God knew before we are born everything we will do.
- If God knew before we are born everything we will do, it is never in our power to do
otherwise. - If it is never in our power to do otherwise, then there is no human freedom. Therefore,
- There is no human freedom.
If we replace “knew” in premise 2 with “decreed,” there is, as we've seen, a very good
reason to accept premise 2. But why should the mere fact that before you were born God
knew that you would now be reading this sentence deprive you of the power not to have
read it? The answer given by those who accept 2 is that to ascribe to you the power not to
have read the sentence you just read is to ascribe to you a power no one can possess: the
power to alter the past. For since you did read the sentence it is true that before you were
born God knew that you would read it. But if a few moments ago it was in your power
not to read it, it seems that it was then in your power to change the past, to make it the
case that before you were born God did not know that you would read that sentence
today. But no one has the power to change the past. And it is not acceptable to say that
until you actually read the sentence in question there was no past fact to the effect that
God knew before you were born that you would read that sentence at the moment you
did. For that simply denies the doctrine of divine foreknowledge, that God knew in
advance what you would do.
Although there is more than one response to this line of argument, the one we shall
consider here is due to William of Ockham (1285–1349) and can be briefly stated. The
basic point Ockham makes is to note a distinction between two sorts of facts about the
past: facts that are simply about the past, and facts that are not simply about the past. To
illustrate this distinction, consider two facts about the past, facts about the year 1941: