DLS MoM VII
From Dorothy L. Sayers, The Mind of the Maker, “VII. Maker of All Things—Maker of Ill Things”
Only X can give reality to Not-X; that is to say, Not-Being depends for its reality upon Being. . . . The bung-hole is as real as the barrel, but its reality is contingent upon the reality of the barrel. . . .
God, according to St. Thomas Aquinas, knows Evil “by simple intelligence”—that is, in the category of Not-Being. But men, not being pure intelligences but created within a space-time framework, could not “know” Evil as Not-Being—they could “know” it only by experience; that is, by associating their wills with it and so calling it into active Being [anti-Being]. Thus the Fall has been described as the “fall into self-consciousness,” and also the “fall into self-will.”
The Fall had taken place and Evil had been called into active existence; the only way to transmute Evil into Good was to redeem it by creation. But, the Evil having been experienced, it could be redeemed only within the medium of experience—that is, by an incarnation in which experience was fully and freely in accordance with the Idea.