Saturday, October 29, 2005

divine foreknowledge

Dr. Hodges poses an interesting question about modal logic and divine foreknowledge.

Me, I'm not a theist, but it seems to me that if God exists and knows every aspect of the future down to the minutest detail, including details about our "free" choices, then I think that foreknowledge indicates lack of freedom.

Note that I say "indicates," not "causes."

An argument with a friend a couple years ago focused on whether foreknowledge is causal. Rem Edwards, in his Reason and Religion, takes the position that divine foreknowledge is, effectively, causal. Arguing that "human foreknowledge isn't causal" is not relevant. But one need not even talk about causality when talking about freedom and foreknowledge. It's enough to say that, if you (or God) definitely know that event X is going to happen, this knowledge is possible only because that event is inevitable.

The example my friend offered-- in demonstrating how foreknowledge is not causal-- was this:

Imagine you start watching a diver the moment after he's jumped. You know for a fact that he's going to get wet, right? At no point did your knowledge cause the wetness.

My reply is:

(1) True, but you know he's going to get wet because, at that point, his getting wet is inevitable. Note, too, that your example doesn't give us any idea how freedom enters the picture.

One could also question whether one really knows what one thinks one knows. Do we truly know for a fact that the diver, once he's left the diving board, will get wet? Here, I offer my Monty Python response, based on a scene in "The Life of Brian":

(2) Brian tumbles out of a tower. By most people's reckoning, Brian is doomed to become street pizza. This doesn't happen. In mid-plummet, Brian is scooped up by a spaceship, swept temporarily into space where he endures a quick space battle, then plopped back on earth when the spaceship crashes. By the same token, there is a chance, however small, that something might happen to the diver en route to the water. Are we absolutely sure the diver, having left the diving board, will get wet?

I was worried, for a while, that responses (1) and (2) were incompatible, but I now see them as perfectly compatible. Both responses say the same thing: 100% sure foreknowledge is possible only when the known event-to-come is inevitable. In response (1), I'm granting that inevitability and noting that there's no freedom. In response (2), I'm granting the freedom but noting its incompatibility with the claim to knowledge. Saying that X is "very likely true" is not the same as knowing X to be true.

I wrote a long while back on middle knowledge, a theological concept that attempts to circumvent the problem of the lack of human freedom in the face of divine foreknowledge. In my view, middle knowledge merely postpones the issue by redefining knowledge-of-events as some sort of if-clause:

If Johnny leaps off the diving board, then he'll get wet.

The "if" indicates, quite simply, lack of foreknowledge. Middle knowledge is non-omniscience, and not compatible with the more widely known, traditional* notion of divine foreknowledge. I don't think there's any getting around that.

A meaty article on middle knowledge is here.

A Wikipedia entry is here.

Knock yerself out.

*The notion of middle knowledge, scientia media, dates back centuries, but isn't part of the traditional, widespread, Christian conception of divine foreknowledge. A quick survey of various sermons and congregants' opinions on the matter will be enough to demonstrate this.


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