Philosophy 348
Fall 2003

The Foreknowledge Argument (Harder Version)

Suppose that t is a time between t- and t+. At t you are deciding whether to do one action, A, or some other action at the later time, t+. Here's a revised principle about power, better than the principle we discussed already. The idea is that if you can't prevent something, then you can't prevent its consequences.

POWER2: If (i) E's occurring at t- is sufficient for S's doing A at t+ and (ii) at t it is not within S's power to prevent E's occurrence at t- then, at t it is not within S's power to avoid doing A at t+.

Next comes a principle that says that you don't have the power, at any given time, to affect things that have already happened.

PAST: If E occurred at t- and t- is before t+, then at t+ it is not within S's power to prevent E's occurrence at t-. [What's done is done. You can't change the past.]

Now, we will apply this to Taylor's situation about ordering a batter.

O: ordering a battle
O': ordering no battle

(Assume that this is a free choice, if anything is. That is, you can do O but it is also true that you can do O'. Furthermore, you can avoid doing O and you can avoid doing O'.)

E1: God's knowing that S would do O now.
E2: God's knowing that S would do O' now.
T-: A 1000 years ago

The Foreknowledge Argument (revised)
1. E1's occurring at T1 is suff. for S's doing O now.
2. E2's occurring at T1 is suff. for S's doing O' now.
3. Either E1 occurred at T1 or E2 occurred at T1.
4. If E1 occurred at T1, then it is not now within S's power to prevent E1's occurrence at T1. [PAST]
5. If E2 occurred at T1, then it is not now within S's power to prevent E2's occurrence at T1. [PAST]
6. If E1 occurred at T1, then it is not now within S's power to avoid doing O now. [(1), (4), POWER2]
7. If E2 occurred at T1, then it is not now within S's power to avoid doing O' now. [(2), (5), POWER2]
8. Either it is not now within S's power to avoid doing O or it is not now within S's power to avoid doing O'. [(4), (6), (7)]
9. If (8), then S is not free with respect to O and O'
10. S is not free with respect to O and O'. (8), (9)

The argument is valid. It can be generalized to other cases of apparent free action. So this looks like a troublesome argument. It does not make the same mistake as the arguments we already looked at.