DOUBTING INSANITY (Folie du doute, Maladie du doute, Grübelsucht) is classed by Régis[22] as a form of melancholia (mélancolie délirante), on the ground that it has the three elements of melancholia—namely, fixed ideas (délire) of a sad nature, general mental depression, and tendency to suicide. The melancholia is secondary, however, rather than primary, and doubting insanity belongs more properly under the head of a psycho-convulsive mental disease closely allied to delusional insanity, like which it is more commonly a manifestation of psychoneurotic heredity, appearing for the most part among the cultivated classes. It consists in an uncontrollable doubt and indecision, unanswerable by any degree of rational explanation, regarding the occupations, duties, or events of the day, religion, a future life, the commonest acts, or the most abstruse problems of life. Doubting insanity essentially depends upon an anomalous action of the will, with imperative conceptions and impulses. It is classed by some writers as a monomania of the degenerative type. Schüle calls it Verrücktheit sensu strictiori, using the term Verrücktheit also for the three forms of primary delusional insanity just described. [Footnote 22: _Manuel pratique de Médecine mentale_.] Délire du toucher, an insane dread of touching certain objects, and the morbid fear of defilement, called by Hammond mysophobia (similar names may be multiplied indefinitely), belong in the same category. There are mild cases of all these forms of disease, which seem like simple weakness of character, others requiring for treatment the conveniences of the retreat for nervous and mental diseases, with a fair prospect of recovery, and still others tending to chronicity in which hallucinations, delusions, and dementia appear only as a further development into another form of insanity. They may, in mild degrees, be symptoms in the course of other mental diseases, especially melancholia, like many other manifestations of morbid mental energy, such as Doctor Johnson's inability to enter a room with his left foot first or to pass a lamp-post without striking it with his cane, etc.