INSANITY. In Medical Jurisprudence.
The prolonged departure, without any ade quate cause, from the states of feeling and modes of thinking usual to the individual in health.
Insanity is such a deprivation of reason that the subject is no longer capable of un derstanding and acting with discretion in the ordinary affairs of life. Snyder v. Sny der, 142 Ill. 60, 31 N. E. 303.
Legal insanity, which exonerates from crime or incapacitates from civil action, is a mental deficiency with reference to the particular act in question and not general incapacity. It is the latter only as the re sult of judicial ascertainment that a per son is non compos mentis, by inquisition in lunacy, or similar statutory proceeding, and this only results in a general civil disability and not, proprio vigore, in immunity from punishment for crime.
It results that there can be no general definition of legal insanity. It is a state or condition which must be noted with refer ence to each class of actions to which it is applied.
In criminal law it "is any defect, weak ness, or disease of the mind rendering it incapable of entertaining, or preventing its entertaining in the particular instance, the criminal intent which constitutes one of the elements in every crime." 1 Bish. New Cr. L. § 381.
As a cause of civil incapacity it is such defect or weakness as prevents rational as sent to a contract or due consideration of the facts properly and naturally entering into the testamentary disposition of one's estate. It is a want of due proportion iu quality or quantity, or both,—between the mental capacity and power and the lar act, civil or criminal, as to which the inquiry arises.
ty are essentially different, and the differ ence is one of substance. The failure to keep it in mind has been the fruitful cause of confusion in trials involving the question of mental capacity for crime or contract, and has tended to render valueless and often absurd the testimony of witnesses called as experts. Many of these have testified with out any conception of the real nature and definition of the insanity, which alone could have relation to the case.
The distinction between the medical and the legal idea of insanity has, perhaps, not been better stated than by Ray, who is quot ed by Ordronaux, and again by Witthaus & Becker: "Insanity in medicine has to do with a prolonged departure of the individual from his natural mental state arising from bodily disease." "Insanity in law covers nothing more than the relation of the person and the particular act which is the subject of judicial investigation. The legal problem
must resolve itself into the inquiry, whether there was mental capacity and moral free dom to do or abstain from doing the partic ular act." 1 Whitth. & Beck. Med. Jur. 181; 11. S. v. Faulkner, 35 Fed. 730.
Of late years this word has been used to designate all mental Impairmenta and deficiencies formerly embraced in the terms lunacy, idiocy, and unsound ness of mind. Even to the middle of the last cen tury the law recognized only two classes of persona requiring its protection on the score of mental dis order, viz.: lunatics and idiots. The former were supposed to embrace all who had lost the reason which they once possessed and their disorder was called dementia acoidentalis ; the latter, those who had never possessed any reason, and this deficiency was called dementia naturalis. Lunatics were sup posed to be much influenced by moon ; and an other prevalent notion respecting them was that in a very large proportion there occurred lucid inter vals, when reason shone out, for a while, from be hind the cloud that obscured it, with its natural brightness. It may be remarked, in passing, that lucid intervals are far leas common than they were once supposed to be, and that the restoration is not so complete as the descriptions of the older writers would lead us to infer. In Modern practice, the term lucid interval signifies merely a remission of the disease, an abatement of the violence of the morbid action, a period of comparative calm ; and the proof of its occurrence is generally drawn from the character of the act in question. It is hardly necessary to say that this is an unjustifiable use of the 'term, which should be confined to the genuine lucid interval that does occasionally occur. It began to be found at last that a large class of persons required the protection of the law, who were not idiots, because they had reason once, nor lunatics in the ordinary signification of the term, because they were not violent, exhibited no very notable derangement of reason, were independent of lunar influences, and had no lucid intervals. Their mental impairment consisted in a loss of intellectual power, of interest in their usual pursuits, of the ability to comprehend their relations to persons and things. A new term—unsoundness of mind—was therefore introduced to meet this exigency ; but it has never been very clearly defined.