Our credulity is greatest concerning the things we know least about. And since we know least about ourselves, we are ready to believe all that is said about us. Hence the mysterious power of both flattery and calumny.

Hoffer links self-ignorance to social manipulability. Because the self is the least examined and least securely known object of knowledge, people are unusually suggestible about their own character and motives. That vulnerability makes external judgments—whether praise or slander—feel revelatory, as if they supply missing information about who we “really” are. Flattery works by offering an attractive identity to inhabit; calumny works by planting a feared identity that can be hard to disprove internally. The “mysterious power” is thus psychological rather than mystical: both forms of speech exploit the same gap in self-knowledge and the human desire for a coherent self-story.