The so-called logical problem of evil suggests that there's a marked inconsistency between the statement "Almighty God exists" and the utterance "evil exists." For if God is almighty and omnibenevolent, then why does evil obtain? This problem was raised long ago by the Greek philosopher Epicurus and the ancient Gnostics.
Notre Dame University Professor, Peter van Inwagen, offers a useful contribution to the growing literature about the logical problem of evil. His book is a solid collection of eight Gifford lectures delivered at the University of St Andrews in May 2003. The prose contained in the work is often impressive, the reasoning is starkly lucid and van Inwagen's philosophical arguments generally are compelling. Hence, these lectures carefully analyze "evil" in order to remove manifold confusions that surround the concept. There are contexts in which "evil" denotes "moral depravity" but other contexts where the denotation is possibly "the absence of good." Defining evil is an arduous task, but the clarification of ideas should precede genuine philosophical analysis.
Before showing the deficiencies evidently associated with the logical problem of evil, van Inwagen posits his idea of God. He reasons that there are certain attributes which God should possess in order to be the maximally excellent entity, that than which a greater cannot be conceived (according to Anselm of Canterbury). These divine qualities include omniscience, moral perfection and omnipotence. The reader is subsequently treated to a definition and insightful analysis of the expression "philosophical failure." What is philosophical failure? How does this notion affect the argument from evil? Those perusing the book have such questions answered. Additionally, they find new distinctions regarding evil (for example, local versus global evil).
In the final analysis, I believe that van Inwagen demonstrates how the argument from evil fails. He establishes (with a certain degree of plausibility) that one cannot rightly argue from evil to the non-existence of God. There are other ways to account for the permission of divinely-preventable evil. To this end, the book addresses animal suffering, predatory activities among beasts and the so-called hiddenness of God. The author wisely frames a number of his arguments in dialogical form by creating two characters known as Theist and Atheist, who argue about the logical problem of evil in front of an imaginary neutral crowd. The dialogue is interesting, to a point, although I believe that van Inwagen tries to be too clever at times.
This philosophical treatise is written for those who have some familiarity with the common vocabulary of metaphysics, the philosophy of religion, and systematic theology. Moreover, I would not call the arguments here conclusive, in any sense of the word, but the read is generally enjoyable and illuminating.