CHAPTER I.

MENTAL DISEASES IN GENERAL.

§ 31. Correct ideas of the pathology of insanity are not unessential to the progress of enlightened views respecting its legal relations. If it be considered as withdrawn from the influence of the common laws of nature, in the production of disease, and attributed to the direct visitation of God; if the existence of physical changes be overlooked or denied, and we are referred exclusively to some mysterious affection of the immaterial spirit, for its cause; then is it in vain to hope, that such a condition can ever be the object of discriminating, salutary legislation. In the prevalence of such views in past times, however, we may look for the cause of much of the error and absurdity, that pervade the law of insanity, and that are equally at variance with the principles of science and the dictates of humanity. It is an undoubted truth, that the manifestations of the intellect, and those of the sentiments, propensities and passions, or generally, of the intellectual and affective powers, are connected with and dependent upon the brain. It follows, then, as a corollary, that abnormal conditions of these powers are equally connected with abnormal conditions of the brain; but this is not merely a matter of inference. The dissections of many eminent observers, among whom it is enough to mention the names of Greding, Gall and Spurzheim, Calmet, Foville, Fabret, Bayle, Esquirol, and Georget, have placed it beyond a doubt; and no pathological fact is better established—though its correctness was for a long while doubted—than that deviations from the healthy structure are generally presented in the brains of insane subjects. In the few cases, where such appearances have not been observed, it is justly concluded that death took place before the deviation was sufficiently great to be perceptible,—a phenomenon, not rare in affections of other organs.

^ 32. These pathological changes are not sufficiently definite to admit of classification, or of practical application in the treatment of the various kinds of insanity. To us they are chiefly valuable, as showing the frequent liability to disease, either from excessive exertion or disuse of its own powers, or from its proneness to be affected by morbid irritations, that radiate from other parts of the body. We learn from them, also, that changes of structure may proceed in the brain, as in other organs, to an incurable degree, without giving rise to much, if any, very perceptible disturbance of its functions, until some striking and unexpected act leads the enlightened physician to suspect its existence, and draws down upon the unfortunate subject the restraints and penalties of the law.

§ 33. A natural classification of the various forms of insanity, though of secondary importance in regard to its medical treatment, will be of eminent service to the legal inquirer, by enlarging his notions of its phenomena, and enabling him to discriminate, where discrimination is necessary to the attainment of important ends. The deplorable consequences of knowing but one kind of insanity, and of erecting that into a standard, whereby every other is to be compared and tested, are too common in the records of criminal jurisprudence; and it is time that it were well understood, that the philosophy of such a method is no better than would be that of the physician, who should recognise no diseases of the stomach, for instance, but such as proceed from inflammation, and reject all others as anomalous and unworthy of attention. The various diseases, included in the general term insanity, or mental derangement, may be conveniently arranged under two divisions, founded on two very different conditions of the brain; the first being a want of its ordinary developement, and the second, some lesion of its structure subsequent to its developement. In the former of these divisions, we have Idiocy and Imbecility, differing from each other only in degree. The various affections, embraced in the latter general division, may be arranged under two subdivisions, Mama and Dementia, distinguished by the contrast they present in the energy and tone of the mental manifestations. Mania is characterized by an exaltation of the faculties, and may be confined to the intellectual, or to the affective powers, or it may involve them both, and these powers may be generally or partially deranged. Dementia depends on a more or less complete enfeeblement of the faculties, and may be consecutive to injury of the brain, to mania, or to some other disease; or it may be connected with the decay of old age. These divisions will be more conveniently exhibited in the following tabular view.

§ 34. It is not pretended, that any classification can be rigorously correct; for such divisions have not been made by nature, and cannot be observed in practice. Diseases are naturally associated into some general groups only; but if these be ascertained and brought into view, the great end of classification is accomplished. We shall often find them running into one another, and be puzzled to assign to a particular disease its proper place; but since such is the order of nature, we must make the most of the good it presents, and remedy its evils in the best manner we can. The above arrangement, with the exception of some slight modifications, is that adopted by Esquirol, and has this advantage over some others, that it preserves the divisions made by nature, and will thus be serviceable to our present purpose, by dissipating some of the false notions, that prevail relative to the nature of insanity.

CHAPTER II.

IDIOCY.

§ 35. Idiocy is that condition of mind, in which the reflective, and all or a part of the affective powers, are either entirely wanting, or are manifested to the slightest possible extent. As the organic defects, on which idiocy depends, are various in kind and degree, and also as it regards the parts of the brain affected, we should be led to expect, what observation shows is actually the case, considerable variety in the manifestations of this condition. The individual may hardly rise to the level of some of the brutes, his movements being confined to the necessities of the automatic life; or he may be capable of performing some useful services, of exercising some talent, or of displaying some of the higher moral sentiments. In short, there is even more diversity, in the characters of the idiotic and imbecile, than in those of the sound, and this truth must not be forgotten, if we would avoid the flagrant error of regulating judicial decisions by rules, which, though perfectly correct in regard to one case or set of cases, may be wholly incorrect in regard to others.

The most striking physical trait of idiocy, and one seldom wanting, is the diminutive size of the head, particularly of the anterior-superior portions, indicating a deficiency of the anterior lobes of the brain.