The Duality of the Mind, by Arthur Wigan
A New View of Insanity: The Duality of the Mind Proved by the Structure, Functions, and Diseases of the Brain and by the Phenomena of Mental Derangement, and Shown to Be Essential to Moral Responsibility (1844) illustrates the idea, not uncommon in the British medical context at the time, that madness was attributable to the uncoordinated, asymmetrical functioning of the two “brains” (Clarke 1987).
Wigan saw each hemisphere as a distinct organ, complete in itself, and therefore capable of exerting independent volitions. While the organism remained healthy, one of the brains exerted control over the other; in pathological conditions, each brain followed its own way and could oppose the other.
The Duality of the Mind proposed a system of cerebral ascesis that emphasized the importance of exercising and cultivating the brain for augmenting its power. The tasks and abilities involved, requiring exercise, self-control, and dedication, were moral as much as pedagogical. The brain must be constantly attentive, always watchful.