Plantinga on The Problem of Evil

I'm continuing to read in Plantinga's "God and Other Minds" and found the chapter on the problem of evil interesting. Since this is probably the most frequently sited apologetic challenge I thought I would summarize his argument here.

The challenge: The existence of evil and the belief in an omnipotent and perfect God are contradictory beliefs. Plantinga suggests that this can be set forth in five propositions essential to traditional theism, with respect to the problem:

a) that God exists
b) that God is omnipotent
c) that God is omniscient
d) that God is wholly good
e) that evil exists

There is no formal contradiction in these five propositions. Some other proposition must be added to this to produce the contradiction. Such a proposition must be:

i) necessarily true

and/or

ii) an essential part of theism

or

iii) a logical consequence of such propositions

Finding an additional proposition that accomplishes the purpose intended has proven to be very elusive (Plantinga surveys the field of suggestions).

Now an omnipotent God is able to eliminate every case of evil and a perfectly good God would want to do so. Plantinga suggests that a proviso should be added to this: this is the case if, and only if, it does not require him to eliminate a greater good in order to do so.

This proviso throws a wrench into the atheological argument from evil. (Consider if Job's suffering produced a state of affairs which is a greater good than would have been the case if the evil had been prevented. The answer to this is at least arguable in the affirmative.)

The atheologian must now prove that unjustified evil exists. That is, "there is at least one evil state of affairs such that for every good that entails it, there is a greater good that does not."

The atheist must show that it is logically impossible that there is evil and that all of it is justified. In other words, "If there is any evil in the world, then there is unjustified evil" must be shown to be a necessarily true proposition. Very difficult to do.