Kant and de Sade:

'The Modern Recalibration of the Monstrous and the Demonic'

Cyril O'Regan at Church Life Journal.

"If Kant surprised himself by feeling compelled to write about 'radical evil' in book 1 [of Religion within the Boundaries of Reason Alone], he shocked Goethe who, feeling betrayed, decried what he judged to be an inexplicable regression to the hateful Christian doctrine of Original Sin. Goethe was only somewhat right in linking Kant’s view of radical evil to the Christian doctrine of Original Sin, and if right at all perhaps only by accident in that certainly Kant intended to debunk Augustine’s doctrine of Original Sin and any of its many offshoots, including those of the Reformers. What Goethe intuited rather than reasoned out was that Kant was saying something quite different from what he had said before: evil is not simply the aggregate of acts that fall short of the pure moral law, rather it has a deep ground in the self: morally bad acts express this ground rather than being the result of it."

See Kant, Perpetual Peace, in Gateway to the Great Books (10 Vol., 1963) volume 7; The Critique of Pure Reason, The Critique of Practical Reason, and The Critique of Judgement, in Great Books of the Western World (first edition, 52 Vol., 1952) volume 42, and (second edition, 60 Vol., 1990) volume 39.