Irrationality and Self-Deception within Kant's Grades of Evil

Scholars have failed to adequately distinguish Kant's grades of evil: frailty (weakness of will), impurity, and depravity. I argue that the only way to distinguish them is, firstly, to recognize that frailty is explicitly, practically irrational and not caused by any sort of self-deception. Instead, it is caused by the radical evil that Kant finds within the character of all persons. Secondly, impurity can only be understood to be self-deception either about the nature of the act itself, which results in an epistemic error, or about one's motivations for following a properly reasoned, moral conclusion, which results in a motivational error. Thirdly, depravity is self-deception about morality itself, by which the agent believes that it is morally right to follow self-love.