feelings. But he credits Pinel as the first in psychiatry to clearly distinguish madness without delerium, in opposition to Locke's widely accepted axiom that insanity always stemmed from faulty intellectual connections or mistaken perceptions. However, Pinel's concept focused on a frenzy of the passions, particularly involving rage and violence. For Prichard the typical syndrome was more a form of extreme eccentricity, and he would later refer to Pinel's type as a madness of the instincts. Prichard was an adherent of what was known faculty psychology, which attempted to divide the mind into different functions or abilities, but not phrenology, which attempted to locate them below specific parts of the skull. He was also influenced by a school of thought associated with the physician Nasse, which posited disorders of emotions or temperament rather than intellect. Prichard also considered a complex categorical scheme developed by Heinroth, concluding that a number of disorders in different divisions of that scheme would be more simply gathered under the heading 'moral insanity'. He suggested the category could also be termed 'parapathia', or alternatively 'pathomania' by analogy with monomania. The latter term had been introduced by the physician Esquirol, who had succeeded Pinel, to refer to a form of insanity where there is a fixation or excess in only one area. It was also used widely by Étienne-Jean Georget. It was theorized to be caused by a split in the faculties of the mind. Prichard considered his first category of intellectual (rather than moral) insanity, to be equivalent to monomania. This in turn meant that the symptoms of moral insanity could increase, causing an overall degeneration into monomania. "On the surface, monomania can thus appear even more circumscribed a form of derangement than moral insanity." However, Esquirol by contrast considered moral insanity to be simply one form of monomania. Context Contemporary misunderstanding of the term derives from the double meaning of the word "moral" in the nineteenth century context. According to Erdmann Mueller in a comprehensive 1899 treatise on moral insanity: "the word moral in the concept moral insanity is derived from the word affective in Esquirol's terminology, and the translation of moral as virtuous or ethical is the result of a misunderstanding due to the double meaning of the word." According to Pinel, manie sans délire (mania without delusion) had no relation to the moral faculty. Moral insanity was a form of mental derangement in which