God's hidden reasons
On the axis: The problem of evil · the one who calls God to account
What if the ends that justify evil exceed all human understanding? To Job, who demands an accounting, God answers not with reasons but with the sheer vastness of his creation.
Justification
How can a good God allow evil to exist? Thomas takes from the thesis that evil is not a thing nor a substance created by God, but a privation, a lack of being or of good that ought to be there, as blindness is the absence of sight. God therefore does not create evil; he permits physical evil for the sake of a greater good in the order of the whole, and moral evil out of respect for free will, without which there would be neither virtue nor merit. The profile thus blends theodicy (evil ordered to the good of the whole) and the free-will defence inherited from Augustine.
Summa Theologiae, Ia, q. 48-49 · Summa contra Gentiles, III, 71
Justification
Can reason and faith contradict each other? Thomas answers no, and his argument rests on a thesis about their shared source: one and the same God is the author of nature, which gives reason its light, and of Revelation; one truth therefore cannot belie another. Against the Averroist doctrine of double truth, which reserved an independent domain for philosophy, he distinguishes without opposing: reason establishes by itself the preambles of faith (the existence of God, the immortality of the soul), while the properly revealed mysteries, such as the Trinity, surpass reason without contradicting it. Where an argument seems to refute the faith, it is because it is badly conducted, and philosophy itself can expose the flaw.
Summa contra Gentiles, I, 3-9 · Summa Theologiae, Ia, q. 1, a. 8
Anchors: Aquinas · Skeptical theism
leads to: Faith and reason