In his initial discussion of various standard objections to theistic belief, Plantinga discusses what he calls the “probabilistic” form of the Problem of Evil. (The “probabilistic” version is what I referred to as the “Evidential Problem of Evil”.) In the interests of time, I didn’t walk through Plantinga’s comments on the Evidential Problem of Evil in class. However, I thought it would be worth having a brief discussion here on the web notes. Plantinga on the Problem of Evil
The Problem
The Evidential Problem of Evil is that theistic belief is improbable with respect to what we know (that there is so much needless evil in the world), so it is irrational to accept the theistic belief that there is an all-perfect God.The set-up is that:
(1) God is the omnipotent, omniscient, wholly good creator of the world.is improbable or unlikely with respect to:(2) There is X amount of evil in the world.Plantinga’s Response
The key to Plantinga’s response is his claim that:Though a proposition (a) may be improbable given another proposition (b), it may not be improbable given another proposition (c) (that is compatible with (b)).Obviously, this is pretty abstract. Let’s illustrate it with an example.
Consider the following list of propositions:(a) Jamie is a law student.Notice that (a) is improbable given (b). If all you knew about law school admissions and about Jamie was (b), then you would consider it very unlikely that (a). That is, if all you knew was that Jamie had a 2.0, you’d consider it very unlikely that she got in to law school.
(b) Most undergraduates with a GPA below a 2.0 don’t get into law school, and Jamie’s undergraduate GPA was 2.0.
(c) Every undergraduate with a perfect scored on the LSAT gets into law school, and Jamie got a perfect score on the LSAT.But notice further that, (a) is not at all unlikely given (b) and (c). If, in addition to (b), you knew that (c), you’d take (a) to be very likely. That is, if you knew that Jamie aced her LSAT, then, even though you knew that she had a 2.0, you’d know that she got in to law school.
The big point here is that what is probable or improbable depends on what other information you’re comparing it to. Something may be improbable with respect to a certain bit of information. But if you had more information, it may cease to be improbable.
Plantinga wants to respond to the Evidentialist Problem of Evil by claiming that this is the case with respect to belief in God. Again, remember the set-up:
(1) God is the omnipotent, omniscient, wholly good creator of the world.is improbable or unlikely with respect to:(2) There is X amount of evil in the world.Plantinga agrees with this set-up. He fully admits that an all-powerful, all-knowing, all-caring God’s existence is improbable with respect to the fact that there is so much evil in the world. That is, if all we knew about the world is that it contains X amount of evil, then we should regard it as very unlikely that a perfect God exists. (In the terminology we employed in the context of the Design Argument, if all we knew about the world was that it contained a lot of evil, then it wouldn’t seem like the best explanation to believe that an all-perfect God was responsible for its design.)But Plantinga thinks that this problem can be solved by considering the likelihood of God’s existence with respect to a wider class of propositions. He wants to claim that when we take account of all of our information (and not just the one bit of evidence we have about evil) we will see that a perfect God’s existence is not rendered improbable.
In essence, Plantinga has to provide something like (c) in the law school example. He needs to provide some third proposition that, when added to (2), makes (1) probable. That is, he needs to provide some bit of information that, when added to our belief that there is X amount of evil in the world, makes it no longer unlikely that an all-perfect God exists.
Now, you might expect Plantinga to enter into a long discussion of the other kinds of evidence that we have at our disposal. But he doesn’t quite do this. On Plantinga’s positive view, it is reasonable to believe that God exists even in the absence of evidence or proof. So, when discussing the set of propositions (the possible (c)’s) against which we should judge the probability of an all-perfect God’s existence, Plantinga’s rather bold question is just this: “Why can’t we include the proposition that God exists in that set of propositions?” (Why couldn’t the needed (c) just be the proposition “God exists”?)
If we could include this, then even though we find a certain amount of evil in the world, this wouldn’t show that a perfect God’s existence is improbable.