336 RELIGION, MORALITY, FAITH, AND REASONComments on the argument
First, note that God knows that P entails P is true; but God knows that P
does not entail God makes P true. An omnipotent God can create a world
in which things are true that God did not cause to be true. An omniscient
God can know things to be true that God did not cause to be true.
Second, we should distinguish between direction of entailment and
direction of truth determination. Entailment is defined this way:
Proposition P entails Proposition Q if and only if “P is true but Q is
false” is a contradiction. Truth determination is defined in this way: A’s
obtaining determines B’s truth if and only if The explanation that B is
true is that A obtains. (To “obtain” is “to be the case” or “to be a fact.”)
Third, suppose that Sally will be tempted to lie tomorrow, but will
finally decide to tell the truth. Then it is true that (S) Sally will tell the
truth tomorrow. Consider that claim, plus (G) God knows that Sally will
tell the truth tomorrow. Note two things: (i) the direction of entailment
goes from (G) to (S) – to get from (S) to (G) one would have to add God is
omniscient; (ii) the direction of truth determination goes from (S) to (G)
- what makes (G) true is that (S) is true, not the other way round.
Fourth, given that the directions of truth determination go as noted, it
is perfectly compatible with (S) being true, and with (G) being true, that
the explanation of Sally’s telling the truth tomorrow is that tomorrow
she freely chooses to tell the truth. Sally can be a libertarianly free moral
agent whose decision to tell the truth explains the truth of (S). The
explanation of (G)’s being true is just that God is omniscient and (S) is
true. This is perfectly compatible with (S) being true because of a free
choice by Sally. If this is so, then divine foreknowledge is compatible with
human freedom. Hence divine foreknowledge is compatible with human
freedom. The argument, then, fails to establish the intended
incompatibility.
How not to understand “God knows today what Sally will
do tomorrow”
1 As inferential knowledge. If X knows today that Sally will do B
tomorrow, and X must infer Sally will do B tomorrow, then X must
know something like this: X must know that A obtains now and that
It is a law that if A obtains now then Sally does B tomorrow. Then
something obtains now the obtaining of which is sufficient for