This essay situates Charlotte Brontë’s novels Jane Eyre and Villette, along with her letters and unpublished poetry, within the nineteenth-century discourse of phrenology and moral management, exposing her ultimate critique of these popular theories as devices of power. Deriving from faculty psychology, both hinged upon self-regulation as a moral necessity, determined by the decipherability of the self. Brontë resisted this established relation between legibility and self-regulation, preferring a theory predicated upon her own developing concept of illegibility -- a potentially limitless imaginative space. The majority of psychologists commonly associated any state of imaginative withdrawal with a lack of inner regulation and moral weakness leading to immorality and insanity. Brontë’s work shows how it is the unrelenting regulation of the imagination through incessant self-control that creates various forms of insanity and becomes ultimately devastating to the self, advocating instead the moral basis of a complex dialectic between self-control and ecstatic self-loss.