Consider the following axiom and two corollaries:
“A wise man [A] proportions his belief [Pa] to the evidence [Gc].”
“Corollary #1: A belief which leaves no place for doubt is not a belief; it is a superstition.”
“Corollary #2: It is wrong always, everywhere, and for anyone to believe anything upon insufficient evidence.” [This is the (in)famous principle expounded by W. K. Clifford contra William James.]
Let us say that A is an agent, Pa is a proportionate action by A, and Gc is the grounding condition (or conditional grounds) for Pa.
Now consider the following statements:
A wise man [A] never plays the lottery [Pa] since the evidence clearly suggests he will not win [Gc].
A good husband [A] adjusts his commitment to his wife [Pa] based on the evident worth of her love [Gc].
A good friend [A] considers someone his friend [Pa] only when he is certain someone will be a great ally [Gc].
A virtuous child [A] bases his attachment to and respect for his parents [Pa] on the evidence that they will raise him well and satisfactorily provide for his success [Gc].
A wise man [A] bases his immediately upcoming decision [Pa] strictly on what he has done before [Gc].
A wise man [A] bases his immediately upcoming decision [Pa] strictly on what the evidence of his senses indicate he will do [Gc].
A wise man [A] bases his adherence to rationality [Pa] on the evidence that it conforms to the reality in which he is immersed [Gc].
A wise man [A] adjusts his commitment to truth [Pa] on the evidence he has for there being such a thing [Gc].
A good man [A] proportions his commitment to his ideals [Pa] to the evidence that they succeed and will be accomplished in his life [Gc].
A good soldier [A] bases his loyalty to his country [Pa] on the evidence that his country will win the conflict at hand [Gc].
I believe you will notice an analogical “soft spot” in all these claims, and, thus, in the original axiom and its corollaries: there is either a distinct circularity in the above claims (e.g., we only see rationality works in reality by rationally applying the fruits of our reasoning to the rationally ordered description of reality) or a crucial non sequitur between them and the goal they describe. After all, on what evidence might we base our assent to the above axiom? And, short of holding that axiom as an evidentially indefatigable proposition, what necessitates that we accept it on purely evidential grounds? Doesn’t it just make good sense to proportion our belief to the evidence for it? If so, however, what sense does it make to say “making good sense” is rooted in evidential certitude? And round and round we go.
The problem with the axiom, insofar as it might be employed against a rational faith like Christianity, is thus twofold: first, evidentialism only goes so far in personal relationships and commitments to the good, and, second, Christianity is a transcendentally personal commitment to the good. Further, and more generally, evidentialism can only dimly acknowledge that our assessment of evidence itself is automatically, and properly, correlated with our ethical and “eudomaniacal” instincts for our own good. It is not irrational to opt for some good even when the evidence for its viability is not deductive, but is often eminently rational to opt for a discernible good even when the evidence for it is “shakier” or “riskier” than we might like on purely logical grounds. This is what James Ross (following St. Thomas Aquinas) means by cognitive voluntarism and cognitive finality: reason is perfected in the willing of known goods for the perfection of our nature. This is, of course, but vintage Thomism:
“… The will necessarily desires that which is presented to it as a good that in every way can satisfy desire, but among the many goods that are proposed to it as desirable by a judgment that is subject to change, the will freely chooses. Thus, a choice follows the last practical judgment, and the will makes that judgment into the last one.“
Again, as St. Thomas said in De Veritate 24, 2: Totius libertatis radix est in ratione constituta (Liberty, whole and entire, has its root in reason). As Jesus Himself said, “You shall know the truth, and the truth shall set you free.” Our rational grasp of the truth frees us in order to will the good conveyed in the truth.
This harks back to the two counter-axioms I listed above that deal with a man’s evidential basis for his ensuing decision. As Richard Taylor argues in Action and Purpose, you can’t know––that is, you have no evidence that proves––what you will choose to do while you are deliberating about what to do. Nevertheless, you do have reasonable aims and relative knowledge of your means while deliberating. The choices you make are neither deductions from past evidence, nor inductions from current evidence, but instead wholly free acts of the whole man willing a certain good (even misperceived). Much the same could be said for the case of choosing to trust God.
In any event, let me wrap this up by reviewing the corollaries, and seeing how they suffer the same core defect as the axiom from which they hang.
#1: “A belief which leaves no place for doubt is not a belief; it is a superstition.”
Is this corollary dubitable? If so, on what grounds should I believe it? If not, …?
#2: “It is wrong always, everywhere, and for anyone to believe anything upon insufficient evidence.”
What is the evidence for this claim? What kind and what amount of evidence would suffice to ground this claim? If it requires sufficient evidence, it can’t be a first principle of reason. If it doesn’t require adequate evidence to be credible, it refutes itself as a non-evidential certitude.
Finally, I would ask the reader to consider the following claims and see how evidence fits into them (as well as how they “fit” into the evidence):
Our certitude of the reliability of our memory is based on evidence.
Our certitude of the reliability of our sensory perception is based on evidence.
Our certitude of the reality of other people’s minds is based on evidence.
Our certitude of the passage of time is based on evidence.
Clearly, these matters do not fall out from evidence; on the contrary, evidence falls out from them. In which case, however, evidence clearly isn’t the supreme grounding condition for wisely proportioned belief. If one can ground the above certitudes without resorting to evidence drawn from them, I will be more amenable to the positivistic evidentialism that motivates the axiom and corollaries that opened this post. As it stands, however, I find such an epistemology and metaphysics stiflingly shallow and self-destructive. Perhaps you disagree.