“The main purpose of this book,” writes Wahlberg, “is to show that the general idea of knowledge by divine, linguistic testimony is intellectually viable,” or, put otherwise, that beliefs grounded in God's own speech can constitute rationally justified knowledge (17). In establishing this agenda, the author sets his face against the prevailing theological winds and challenges the modern tendency to dismiss propositional accounts of revelation in favor of exclusively manifestational descriptions.
Wahlberg begins building his case in chapters 1 and 2 by explicating the problem of knowledge of God, exposing the inadequacy of an exclusively manifestational (i.e., nonpropositional) account of revelation for addressing this problem, and articulating what constitutes knowledge. “Knowing,” he asserts, “is an attitude that a subject has to a proposition” (26). In other words, knowing is always knowing that—for example, that one is in a classroom, that the cat is black, or that God exists. Most of what any person knows—including, argues Wahlberg, knowledge of God—is testimonial knowledge gained from the spoken or written words of others.
The author contends that the problem with exclusively manifestational accounts of revelation is that they cannot explain how humans are rationally justified in their knowledge that the God they believe in (viz., One who is necessary, omniscient, omnipotent, etc.) exists. If knowledge of God is possible, humans must gain access to that knowledge through either a potent natural theology or testimonial/propositional revelation or both. Wahlberg brackets the former possibility in this book, focusing his attention on testimonial revelation.
In chapter 3, the author surveys four prominent manifestational accounts of revelation as categorized in Avery Dulles' Models of Revelation along with postliberal accounts that do not fit neatly within Dulles' models, arguing persuasively that each of these models in fact includes a propositional component. After a discussion of what it means to say that God “speaks” in chapter 4, Wahlberg moves on to the crux of his argument in chapter 5, an exposition of John McDowell's argument that testimony, like perception and memory, constitutes an irreducible, sui generis source of justification for knowledge. McDowell's antireductionist account of testimonial knowledge provides the foundation for the remaining chapters, in which Wahlberg examines how God's speaking through prophets and especially Jesus, validated by miracles, makes knowledge of God possible.
The crucial move made by both Wahlberg and McDowell is an appeal to the inherent vulnerability of human knowledge and the claim that if we ascribe the status of knowledge to beliefs grounded in perception and memory, we must reasonably ascribe the same status to beliefs grounded in testimony, which is similarly dependent upon factors beyond the subject's control. Following this reasoning, Wahlberg concludes that knowledge of God can indeed be justified, albeit not by evidence for God's reliability but rather by God's testimony itself.
The author writes with exceptional lucidity and clarifies the book's complex subject matter with illuminating illustrations. As he constructs his carefully argued case, he engages an impressive array of theological and philosophical thinkers and evenhandedly entertains a host of counterarguments and possible objections. It is therefore in no way an indictment of the author to say that the abundant (but not gratuitous) technical philosophical language, protracted argumentation, and in-depth treatment of the arguments of key authors make this book more appropriate for a graduate rather than an undergraduate readership.
Although minor aspects of the author's argument occasionally fail to obtain (e.g., 120–22), these are rare exceptions in a generally precise and highly persuasive work. In the opinion of this reviewer, Wahlberg is successful in his aim of rehabilitating the propositional account of revelation and makes a compelling case that divine testimony makes knowledge of God possible, though the latter point will undoubtedly be contested by those who are not convinced by McDowell's antireductionist account of testimonial knowledge. These points notwithstanding, regardless of where one comes down on this point, the fact remains that Wahlberg has produced a valuable book that henceforth must be reckoned with in discussions of the nature of revelation.
