(μόνος, single, and , μανία, madness) has loosely been made to represent every form of partial insanity, but has been more rigidly defined as that mental condition in which a single faculty, or class of faculties or associations, become diseased, the mind generally remaining healthy. Slight and solitary aberrations — such as where a savage antipathy to cats coexists with a love for human kind; where there appears to be an incontrollable tendency to steal, to squander, to drink, to destroy — are of common occurrence, and are supposed to be compatible with the exercise of intelligence, and with the discharge of many of the ordinary duties of life. By a more strict limitation, the term has been confined to such affections as involve the emotions and propensities alone. It is, however, held that, notwithstanding its apparent integrity, the whole mind is involved or influenced by the presence of such morbid conditions, at least while they are predominant. It is undoubtedly difficult to point out in. what manner the belief, e.g., that a particular organ has been transmuted into glass can interfere with or render the memory, or the power of instituting comparisons, defective and untrustworthy; yet it is legitimate to receive with caution every manifestation of powers so constituted that they fail to detect the incongruities and absurdities with which they are associated, or, having detected the real character of these errors, are unable or unwilling to cast them out or to disregard them. There is much countenance given to this theory by facts which indicate that even trivial forms of mental obliquity are connected with an unsound organization, and that particular and rarely recognised monomanias are invariably associated with the same
structural alteration. The unhealthy elevation of the sentiment of cautiousness, for example, especially where it amounts to fear of death, panic, or panphobia, is a symptom of disease of the heart and large blood- vessels, while the monomania of ambition (or optimism, as it has been styled) is the concomitant of the general paralysis of the insane. It will be obvious, from the definitions previously introduced, that the species or varieties of monomania must correspond to the faculties or phases of the human mind, and to their combinations. Several great divisions, however, have been signalized, both on account of their frequency and of their influence upon the individual and upon society.
1. Monomania of suspicion, comprehending doubts in the fidelity and honesty of friends and those around, belief in plots and conspiracies, the dread of poison; and where, as is often the case, it is conjoined with cunning, the propensity to conceal, mystify, and deceive. This malady has frequently been observed in intimate connection with cancer and malignant growths.
2. Monomania of superstition and unseen agencies, where credulity, mingled with religious awe, peoples the external world with spectres, omens, mysteries, magnetism, and the imagination with horrors or ecstatic reveries. Insensibility to pain, or indifference to external injuries, has been observed as a characteristic of individuals affected with this disease.
3. Monomania of vanity, or euphoria, where display and ostentation are indulged, without reference to the position and means of the patient.
4. Monomania of fear.
5. Monomania of pride and ambition.
6. Kleptomania (q.v.).
7. Dipsomania, or Oinomania (q.v.). If it can. be proved that such morbid tendencies as have been here mentioned, and others still less prominent, are merely salient points of a great breadth and depth of mental disease, the plea of insanity may justifiably be employed more frequently in the consideration of criminal acts. — Chambers, s.v. Dr. Forbes Winslow, in The Pill Mall Gazette, holds that what is called partial insanity, or monomania, is not sufficient to prove of itself a testamentary incapacity. "I have often," he says, "witnessed among the insane the possession of delicate, just, and honorable ideas respecting their own social position, and the pecuniary claims of those most near and dear to them." He approves the action of ecclesiastical judges in former times, who, when a will was brought before them to be contested, inquired, first, if there were prima facie evidence in the wording, arrangement, etc., of the will that its author was insane; and, next, whether the testator's lunacy were visible in the distribution of his property. If neither of these points was established, the will generally stood against unquestionable evidence of mental unsoundness or eccentricity in other things. He quotes a case where the testator left a large fortune to his housekeeper, and directed in the same will that his executors should make fiddle-strings of part of his bowels and smelling-salts of others, and that the rest of his body be vitrified into lenses for optical purposes. He did this, he said, to mark his moral aversion to funeral pomp. It appeared that he had conducted his affairs with great shrewdness and ability. See Esquirol, La Monomanie; Bayle, Maladies du Cerveau; Stephens, Criminal Law of England, page 92.