The Foreknowledge Argument

The foreknowledge argument is supposed to establish the truth of determinism. I think it works in the favor of determinism (of the divine kind not the naturalistic, causal kind). Whether or not one is convinced by the conclusion of the argument is dependent, at least in part, on whether or not one can come up a valid form of the argument. In this post I intend to provide one (but not invent or originate one; only to repeat one from my elders and betters).

First, let's distinguish determinism from fatalism. Fatalism is the view that whatever happens must happen. There is no way things could have been anything other than what they are. This is to be distinguished from determinism that holds that there is some antecedent condition such that, given that condition obtaining, it is not possible that things could have been other than what they are. It has been suggested that fatalism is supported by the logical entailment of the following: if it is true that some event, e, will occur, then e will occur (Aristotle said something like this). Graham Priest explains it this way:

Take any claim you like--say, for the sake of illustration, that I will be involved in a traffic accident tomorrow. Now, we may not know yet whether or not this is true, but we know that either I will be involved in an accident or I won't. Suppose the first of these. Then, as a matter of fact, I will be involved in a traffic accident. And if it is true to say that I will be involved in a traffic accident and Then it cannot fail to be the case that I will be involved. That is, it must be the case that I will be involved. Suppose, on the other hand, that I will not, as a matter of fact, be involved in a traffic accident tomorrow. Then it is true to say that I will not be involved in an accident; and if this is so, it cannot fail to be the case that I won't be in an accident. That is, it must be the case that I am not involved in an accident. Whichever of these two does happen, then, it must happen. This is fatalism.

Priest suggests that the argument trades on an ambiguity. The truth that is established in the argument is that if it is true to say something, then whatever it is you have said is the case. However, the argument fails to establish the necessity of the following claim: if it was in fact the case that it was true in the past that Graham would suffer in a car accident then there is no possibility that he wouldn't. 

Consider the following: "If Fred is going to be divorced then he cannot fail to be married." Priest tells us that this means that divorce is not possible for non-married people. However, what the fatalism argument needs is something to make it necessarily true that Fred is married, but the problem is that his getting a divorce won't make him married. Thus, the fatalism argument, at least this version, doesn't get what it wants.

The foreknowledge argument is not the same as the fatalism argument. Instead of a logical necessity, it poses a threat to indeterminism by arguing that there has been such an event in the past that makes a certain event in the future inevitable. It is based on the premise that you can’t change the past: 

“So: (i) necessarily, yesterday God infallibly believes that you will do X today, and since (ii) God’s infallible belief that you will do X today entails that you will do X today, then (iii) necessarily you will do X today” (Paul Manata, Free Will, Moral Responsibility, and Reformed Theology: A Contemporary Introduction). 

The first thing to notice is that this is not a logical necessity. (i) is about God’s past beliefs. Those beliefs are now in the past and cannot be changed (because you can't change the past). Some theologians consider God to be timeless and so those beliefs are even less subject to change. As Linda Zagzebski puts it, “If there is no use crying over spilt milk, there is no use in crying over timelessly spilt milk either” (Zagzebski, “Recent Work on Divine Foreknowledge and Free Will,” in The Oxford Handbook of Free Will (Oxford University Press, 2005), p. 52). Consequently, the argument rests on an accidental necessity. An event in the past makes it the case that a future event cannot fail to occur. The event in question is the infallible belief that God has that in the future that event will  happen. Given his infallible belief, the event in question cannot fail to happen. As Zagzebski concludes: 

God knew at t1 that A will do X at t2. If A does not do X at t2 then God does not know the future. Or God knows timelessly that A will do X at t2. Either way, though not logically entailed, the outcome is necessitated (accidentally). It might have been true at t1 that A will do X at t2, but that is not what the argument suggests. What the argument suggests is something happened at t1. If something happens at t1, then there is noting one can do to change it at t2. Something did happen – a state of affairs obtained at t1 in the form of God believing that at t2 A will do X. Propositions are not the kinds of things that obtain or take place; they are the kinds of things that are true or false. Therefore, the foreknowledge argument stands (Zagzebski, The Dilemma of Freedom and Foreknowledge, 28-31)

Of course, there are many replies worth considering that seek to avoid determinism, but most of them consider the foreknowledge argument to be valid. Most responses seek to show that just because God knows something in the future it is not determined.