Having set out his basic methodology and a list of epistemic platitudes, in Chapter 3 of "Crossing the Threshold..." William Abraham begins to apply this approach to a particular form of theism, namely, Canonical theism. Recall that, for Abraham, is it potentially more fruitful to explore the particular epistemological issues found within a certain belief structure than to begin with a system of knowledge and seek to explain theism in light of that system. So, he now begins to deal with appropriate epistemic fit as applied to Canonical theism.
It is vital, says Abraham, to note that Canonical theism, like all theisms, is far more than a series of abstract propositions. It is, rather, "first and foremost a rich ontology." What this means is Canonical theism is a "world-orienting network of beliefs." (p. 44) So, we cannot expect any single epistemological tool to successfully determine its truth or falsehood - in fact, with any such network of beliefs, we are dealing not only with differing claims of truth, but also different types of belief, and a variety of arguments that may or may not be equally applicable.
So, what is the Canonical theist to do? Here, Abraham draws again upon the principle of proper epistemic fit. Just as we would not measure historical claims using scientific arguments, we need not assume that theological claims can be properly measured by the arguments used in another particular field of inquiry, or network of beliefs. They may be applicable, but we should not begin with that assumption. This, of course, does not mean that Canonical theism (or any theism) will be proved true, but it does offer an important reminder of the limitations we often ignore when trying to disprove a different belief system using the tools appropriate to our own belief system.
Of course, this itself may be viewed as an antiquated notion by some who, having seen the immense power of the scientific model, have determined that all beliefs can be epistemologically proved or disproved based upon how properly they align with the principles of scientific inquiry. So, we have naturalistic atheists who begin with the assumption that Darwinian theory and neurological connections provide conclusive evidence of theistic falsehood. But, these approaches are no less mistaken than (and, in fact, are a rebuttal to) those Christian epistemologists who attempted to explain scientific principles using the words of Scripture. The two spheres simply do not permit that sort of external argumentation. Further, there can be no "single proof" that would prove or disprove a belief system. (p. 46)
Abraham is not naive to the implication of his approach; he admits that Canonical theism could be disproved if, by proving conclusively that Jesus never existed or showing that an invisible God is a self-contradictory idea, its "central concepts" are invalid. (p. 46) But surely this is the basic problem: Many scholars, with all sorts of different 'world-orienting' belief systems, have been able to provide well-developed reasons why we should doubt the central claims of theism. How do we know which theories are the most reliable? At what point does critical reasoning give us enough cause to proclaim Canonical theism effectively untrue? The debate here is never-ending.
So, it seems that we have not traveled very far in our epistemological quest. At this point, Abraham points out what has become one of the most popular current approaches to bolstering the claims of theists, namely, the idea of warrant as developed by the Christian philosopher Alvin Plantinga. Put briefly, there are basic beliefs that we hold as human beings which need no previous justification - they are believed, not because of evidence, but because they are warranted beliefs. Examples of these sorts of beliefs include belief in a real, external world, belief in the past, and belief in other minds. The warrant for belief in God is secured by "the proper functioning of the sensus divinitas, that is, divine sense. (p. 47) Basically, if our divine sense is working properly, we will know properly that God exists. If we do not know this, it is because our sensus is malfunctioning, which is precisely what Christianity describes as sin.
Now, while Plantinga's development of warrant is much more impressive and precise than the brief overview I have just given, nevertheless Abraham sees potential problems with this approach. His main concern is just that, in order to appeal to the idea of the sensus, its malfunctioning and subsequent healing in Christ, we have to first appeal to a particular understanding of Christian belief which means assuming that we have understood these concepts themselves correctly. Thus, we are left with an endless circular structure in which we can only speculate upon which explanation of the divine sense is actually the one which is not faulty.
So, in spite of its epistemological ingenuity, Abraham is not satisfied with the concept of warrant, and admits that we have not gotten very far yet. At this point, it is tempting to think that Barth may be right after all, and the question of truth should really be left up to unadulterated faith. Abraham, of course, does not go down that road, but I am beginning to think that maybe he should admit his own road is not as far of a stretch away from Barth's as he might hope. Abraham essentially admits that Canonical theism is epistemologically dependent upon "complexity, mystery, density, and paradox." (p. 52) If so, then he ought to, in my opinion, be less eager to dismiss all fideistic belief as devoid of value.
Abraham finishes the chapter by providing some outlines of what the epistemological structure of Canonical theism entails. It is, he reminds us, not readily subject to proof, but can be disproved or strained. It cannot be secured by "properly basic beliefs." But it is not an "all-or-nothing affair." We have to consider both events and our experience of those events, as well as the testimony of others. All of this is necessary. (p. 54) However, this is not a vindication; it is a recognition of the epistemic limits we face as believers. (Ironically, Abraham returns here to the idea of cognitive capacities healed by God's Spirit. This seems contradictory, given that he just explained the limitations of this argument.)
Believers, Abraham notes, "rest content with trusting in God," remembering that our faith depends at its center in a divine revelation from an unknowable source: God. Here is where Abraham begins to move toward the next main section of the book. In the next chapter, he will begin to develop both a description of divine revelation, and its place in the 'epistemological toolbox' used by Canonical theists. In fact, as we will see, revelation has a larger and more profound role to play, and is pivotal to our epistemological convictions.