When Are Appeals to Human Ignorance a Legitimate Defeater of an Evidential Argument?

(A1) Evidential arguments from ‘evil’ say: known facts about the types, quantity, and distribution of good and evil are much more probable on naturalism than on theism.

(O1) Critics of evidential arguments from evil say: we don’t know that. We have far too limited an understanding of the interconnectedness of things to make such a judgment with confidence. On the assumption that theism is true (and there exists a morally perfect and omniscient being), there could easily be reasons, way beyond our understanding, why such a being would allow the facts about good and evil to obtain.

(A2) Evidential arguments from cosmic ‘fine-tuning’ say: the life permitting conditions of our universe are much more probable on theism than on naturalism.

(O2) Critics of such arguments say: we don’t know that. We have far too limited an understanding of the early universe, the total mass-energy of the universe, quantum gravity, etc. to make such judgments with confidence. (Cosmology is a very young discipline and there is much we still don’t know. For example, 95.1% of the total mass-energy of the universe is mysterious, composed of either ‘dark energy’ (68.3%) or ‘dark matter’ (26.8%).) On the assumption that naturalism, a/k/a source physicalism, is true (and there was no one around at the earliest stages of the universe’s history to make physical observations), there could easily be mechanistic explanations, way beyond our understanding, why our universe is life-permitting.

I’ve never understood why most proponents of (A2) seem to think (O1) is a good defeater of (A1) while not simultaneously thinking (O2) is a good defeater of (A2).