But the fact that Christianity can only be shown to be probably true need not be troubling when two things are kept in mind: first, that we attain no more than probability with respect to almost everything we infer...without detriment to the depth of our conviction and that even our non-inferred, basic beliefs may not be held with any sort of absolute certainty...; and second, that even if we can only show Christianity to be probably true, nevertheless we can on the basis of the Spirit's witness know Christianity to be true with a deep assurance that far outstrips what the evidence in our particular situation might support (think analogously of the person convinced of his innocence even though all the evidence stands against him). To demand logically demonstrative proofs as a pre-condition for making a religious commitment is therefore just being unreasonable.