It is easier to say what this condition is not than what it is. It is not manifested to the senses by weight or color, dryness or moisture, hardness or softness. In these particulars all brains are pretty nearly alike. When the cerebral action stops and the man dies, we may find lesions visible enough to the sense,—vessels preternaturally engorged with blood, effusions of lymph, thickening of the membranes, changes of color and consistency,—but no one imagines these to be the cause and origin of the disturbance. Behind and beyond all this, in that intimate constitution of the organic molecules which no instrument of sense can bring to light, lies the source of mental activity, both healthy and morbid. There lies the source of all cerebral dynamics. Of this we are sure, unable, as we are, to demonstrate the fact to the senses.
Scientific observation has made us acquainted with some of the agencies which vitiate the quality of the brain, and it is our duty to profit by its results. The principal of them is morbid action in the brain itself, producing, more or less directly, disorder and weakness. But its deteriorating influence does not cease with the individual. In a large proportion of cases it is transmitted to the offspring; and though it may not appear in precisely the same form, yet the tokens of its existence are too obvious to be overlooked.—Another agency scarcely less efficient is that of neuropathies, to use the medical term,—meaning the various forms of disorder which have their origin in the brain, and comprising not only epilepsy, hysteria, chorea, and other convulsive affections, but that habit of body and mind which makes a person nervous. While they may abridge the mental efficiency of the patient comparatively little or not at all, they may exert this effect, and often do, in the highest degree, on his offspring. The amount of insanity in the world attributable to insanity in the progenitors, and therefore called, par éminence, hereditary, is scarcely greater than that which originates in this manner, and of which the essential condition is no less hereditary.—Another agency, acting on a large scale in some localities, is exerted by those diseases which are attributed to some disorder of the lymphatic system, as scrofula and rickets. Though not entirely unknown to the affluent classes, yet it is chiefly in the dwellings of the poor that these diseases find their victims. Cold, moisture, bad air, deficient nourishment,—too frequent accompaniments of poverty,—are peculiarly favorable to their production. The physical depravation thus induced is frequently transmitted to the brain in the next generation, and appears in the shape of mental disorder.—Again, it is now well known that the qualities of the race are depreciated by the intermarrying of relatives. The disastrous influence of such unions is exerted on the nervous system more than any other, and is a prolific source of deaf-mutism, blindness, idiocy, and insanity. Not, certainly, in all cases do we see these results, for the legitimate consequences of this violation of an organic law are often avoided by the help of more controlling influences, but they are frequent enough to remove any doubt as to their true cause. And the chances of exemption are greatly lessened where the marriage of consanguinity is repeated in the next generation. The manner in which the evil is effected may be conjectured with some approach to correctness, but to speculate upon it here would lead us astray from our present purpose. The amount of the evil may be thought to be comparatively small, but they who have a professional acquaintance with the subject would hardly undertake to measure the dimensions of all the physical and mental suffering which it involves. In one State, at least, in the Union, it has seemed formidable enough to require an act of the legislature forbidding the marriage of cousins.—The last we shall mention, among the agencies concerned in vitiating the quality of the brain, is that of excessive or long-continued intemperance; and for many years it has been a most fruitful source of mental deterioration: not, however, in the way which is generally imagined; for, though it may add some effect to a popular harangue to attribute a very large proportion of the existing cases of insanity directly to intemperance, yet, as a matter of fact, very few, probably, can be fairly traced to this cause solely. And yet, at the present time, it is unquestionably responsible for a very large share of the mental infirmities which afflict the race. The germ of the evil requires a second, perhaps a third, generation to bring it to maturity. And then it may appear in the form of mania, or idiocy, or intemperance. As a cause of idiocy, its potency has been placed beyond a doubt. Dr. S.G. Howe, whose thorough investigations entitle his conclusions to great weight, says, that, "directly or indirectly, alcohol is productive of a great proportion of the idiocy which now burdens the Commonwealth." There is this curious feature of its deteriorating influence, that the primary effect is not always persistent, but may be removed by removing the cause. In the Report of the Hospital at Columbus, Ohio, for 1861, the physician, Dr. Hills, says of one of his patients, that his father, in the first part of his married life, was strictly temperate, "and had four children, all yet remaining healthy and sound. From reverses of fortune, he became discouraged and intemperate for some years, having in this period four children, two of whom we had now received into the asylum; a third one was idiotic, and the fourth epileptic. He then reformed in habits, had three more children, all now grown to maturity, and to this period remaining sound and healthy." Another similar case follows. An intemperate parent had four children, two of whom became insane, one was an idiot, and the fourth died young, in "fits." Four children born previous to the period of intemperance, and two after the parent's reformation, are all sound and healthy. Often, it is well known, intemperance in the child is the hereditary sequel of intemperance in the parent. The irresistible craving, without the preliminary gradual indulgence, and in spite of judicious education, generally distinguishes it from intemperance resulting from other causes.
All these agencies have this trait in common, that their damaging effect is often felt by the offspring as well as the parent, and, in most cases, in a far higher degree. The common doctrine of hereditary disease implies the actual transmission of a specific form of disease fully developed,—or, at least, of a tendency to it that may or may not be developed. The range within which it operates is supposed to be the narrow limits covered by a single specific affection. Daily experience, however, shows that the deviation from the primitive type is limited only by some conditions of structure. Any pathological result may be expected, not incompatible with the structure of the organ. And thus it is that the cerebral affection which fell upon the parent is represented in one child by insanity, in another by idiocy, in another by epilepsy, in another by gross eccentricity, in another by moral perversities, in another by ill-balanced intellect,—each and all implying a brain more or less vitiated by the parental infirmity. There is nothing strange in all this diversity of result. In the healthy state, organic action proceeds with wonderful regularity and uniformity; but when controlled by the pathological element, all this is changed, although the change has its limits. This diversity in the results of hereditary transmission is as strictly according to law as the similarity of features exhibited by parent and child. No presumption against the fact can be derived from this quarter, and therefore, if well-authenticated, it must be admitted. Many a man, however, who admits the general fact, refuses to make the application where it has not been usually made. When mania occurs in two or three successive generations, nobody overlooks the hereditary element; but when the mania of the parent is followed by great inequalities of character, or strange impulses to criminal acts, then the effects of disease are straightway ignored, and we think only of moral liberty and free-will. It may be difficult, sometimes, to make the proper distinction between the effects of hereditary physical vitiation and those of bad education and strong temptations; but the difficulty is of the kind which stands in the way of all successful inquiry, to be overcome by patient and profound study.
Some light may be thrown on this deviation from the original type by considering the forces that are concerned in the hereditary act. The statement that like produces like is the expression of an obvious law. But we must bear in mind that the law is only so far observed as is necessary to maintain the characters of the species. Within that range there is every possible variety, and for a very obvious reason. Every individual represents immediately two others, and, indirectly, an indefinite number. This is done by uniting in himself qualities and features drawn from each parent, without any obvious principle or law of selection and combination. One parent may be, apparently, more fully represented than the other; the defects of the parent may be transmitted, rather than the excellences; the tendencies to health and strength may be outnumbered and overborne by the tendencies to disease. No individual, of course, can receive, entirely and completely, the features and attributes of both parents, for that would be a sort of practical absurdity; but in the process of selecting and combining, Nature exhibits the same inexhaustible variety that appears in all her operations. Even in the offspring of the same parents, however numerous, uniformity in this respect is seldom so obvious as diversity. This cerebral deterioration is subject to the same laws of descent as other traits, with a few exceptions without much bearing on the present question. We might as reasonably expect to see the nose or the eyes, the figure or the motions of either parent transmitted with the exactest likeness to all the offspring, as to suppose that an hereditary disease must necessarily be transmitted fully formed, with all the incidents and conditions which it possessed in the parent. And yet, in the case of mental disease, the current philosophy can recognize the evidence of transmission in no shape less demonstrative than delusion or raving. Contrary to all analogy, and contrary to all fact, it supposes that the hereditary affection must appear in the offspring in precisely the same degree of intensity which it had in the parent. If the son is stricken down with raving mania, like his father before him, then the relation of cause and effect is obvious enough; but if, on the contrary, the former exhibits only extraordinary outbreaks of passion, remarkable inequalities of spirit and disposition, irrelevant and inappropriate conduct, strange and unaccountable impulses, nothing of this kind is charged practically to the parental infirmity.
The cerebral defect once established, the modes in which it may be manifested in subsequent generations present no uniformity whatever. Insanity in a parent may be followed by any possible form of mental irregularity in the descendant,—insanity, idiocy, epilepsy, drunkenness, criminal impulses, eccentricity. And so, too, eccentricity, even of the least prominent kind, may be followed by grosser eccentricity, or even overt insanity, in the descendant. The cerebral defect is not necessarily manifested in an uninterrupted series of generations, for it often skips over one, and appears with redoubled energy in the next; and thus, in looking for proof of hereditary disease or defect, we are not to stop at the next preceding generation. We are too little acquainted with the laws of hereditary transmission to explain these things. We know this, however, that, side by side with that law which decrees the transmission of defects as well as excellences, there exists another law which restrains deviations from the normal type, which extinguishes the errant traits, and reestablishes the primitive characters of the organism. The combined and alternate action of these two laws may produce some of the inscrutable phenomena of hereditary transmission.
The transmission of the cerebral defect is often manifested in a manner exceedingly embarrassing to all who hold to the prevalent notions respecting sanity and insanity. It is sometimes confined to a very circumscribed range, beyond which the mind presents no material impairment. The sound and the unsound coexist, not in a state of fusion, but side by side, each independent of the other, and both derived from a common source. And the fact is no more anomalous than that often witnessed, of some striking feature of one parent associated in the child with one equally striking of the other. It is not the case exactly of partial insanity, or any mental defect, super-induced upon a mind otherwise sound,—for such defect is, in some degree, an accident, and may disappear; but here is a congenital conjunction of sanity and insanity, which no medical or moral appliances will ever remove. These persons may get on very well in their allotted part, and even achieve distinction, while the insane element is often cropping out in the shape of extravagances or irregularities in thought or action, which, according to the stand-point they are viewed from, are regarded either as gross eccentricity, or undisciplined powers, or downright insanity. For every manifestation of this kind they may show no lack of plausible reasons, calculated to mislead the superficial observer; but still the fact remains, that these traits, which are never witnessed in persons of well-balanced minds, are a part of their habitual character. When people of this description possess a high order of intellectual endowments, the unhealthy element seems to impart force and piquancy to their mental manifestations, and thus increase the embarrassment touching the true character of their mental constitution. When the defect appears in the reflective powers, it is often regarded as insanity, though not more correctly than if it were confined to the emotions and feelings. The man who goes through life creditably performing his part, but feeling, all the while, that everybody with whom he has any relations is endeavoring to oppose and annoy him, strays as clearly from the track of a healthy mind as if he believed in imaginary plots and conspiracies against his property or person. In neither case is he completely overcome by the force of the strange impression, but passes along, to all appearance, much like other men. Insane, in the popular acceptation, he certainly is not; but it is equally certain that his mind is not in a healthy condition. Lord Byron was one of this class, and the fact gives us a clew to the anomalies of his character. His mother was subject to violent outbreaks of passion, not unlike those often witnessed in the insane. On the paternal side his case was scarcely better. The loose principles, the wild and reckless conduct of his father procured for him the nickname of "Mad Jack Byron"; and his grand-uncle, who killed his neighbor in a duel, exhibited traits not very characteristic of a healthy mind. With such antecedents, it is not strange that he was subject to wild impulses, violent passions, baseless prejudices, uncompromising selfishness, irregular mental activity. The morbid element in his nervous system was also witnessed in the form of epilepsy, from which he suffered, more or less, during his whole life. The "vile melancholy" which Dr. Johnson inherited from his father, and which, to use his own expression, "made him mad all his life, at least not sober," never perverted nor hampered the exercise of his intellectual powers. He heard the voice of his distant mother calling "Sam"; he was bound to touch every post he passed in the streets; he astonished people by his extraordinary singularities, and much of his time was spent in the depths of mental distress; yet the march of his intellect, steady, uniform, and measured, gave no token of confusion or weakness.
In common life, among an order of men unknown beyond the circle of their neighborhood, this sort of mental dualism witnessed with remarkable frequency, though generally regarded as anomalous and unaccountable, rather than the result of an organic law. In some, the morbid element, without affecting the keenness of the intellect, is more active, intruding itself on all occasions, characterizing the ways and manners, the demeanor and deportment. Under the influence of peculiarly adverse circumstances, they are liable to lose occasionally the unsteady balance between the antagonistic forces of their mental nature, to conduct as if unquestionably insane, and to be treated accordingly. Of such the remark is always made by the world, which sees no nice distinctions, "If he is insane now, he was always insane." According as the one or the other phasis of their mind is exclusively regarded, they are accounted by some as always crazy, by others as uncommonly shrewd and capable. The hereditary origin of this mental defect in some form of nervous affection will always be discovered, where the means of information are afforded.
In some persons the morbid element appears in the shape of insensibility to nice moral distinctions. Their perception of them at all seems to be the result of imitation rather than instinct. With them, circumstances determine everything as to the moral complexion of their career in life. Whether they leave behind them a reputation for flagrant selfishness, meanness, and dishonesty, or for a commendable prudence and judicious regard for self,—whether they always keep within the precincts of a decent respectability, or run into disreputable courses,—depends mostly on chance and fortune. This intimate association of the saint and the sinner in the same individual, common as it is, is a stumbling-block to moralists and legislators. The abnormal element is entirely overlooked, or rather is confounded with that kind of moral depravity which comes from vicious training And, certainly, the distinction is not always very easily made; for, though sufficient light on this point may often be derived from the antecedents of the individual, yet it is impossible, occasionally, to remove the obscurity in which it is involved. However this may be, it is a warrantable inference from the results of modern inquiry, that the class of cases is not a small one, where the person commits a criminal act, or falls into vicious habits, with a full knowledge of the nature and consequences of his conduct, and prompted, perhaps, by the ordinary inducements to vice, who, nevertheless, would have been a shining example of virtue, had the morbid element in his cerebral organism been left out. In our rough estimates of responsibility this goes for nothing, like the untoward influences of education; and it could not well be otherwise, though it cannot be denied that one element of moral responsibility, namely, the wish and the power to pursue the right and avoid the wrong, is greatly defective.
There is another phasis of cerebral defect not very unlike the last, which of late years has been occurring with increasing frequency, embarrassing our courts, confounding the wise and the simple, and overwhelming respectable families with shame and sorrow. With an intellect unwarped by the slightest excitement or delusion, and with many moral traits, it may be, calculated to please and to charm, its subjects are irresistibly impelled to some particular form of crime. With more or less effort they strive against it, and when they yield at last, their conduct is as much a mystery to themselves as to others. Ordinary criminals excite some touch of pity, on the score of bad education or untamed passions; but if, in the common estimation of the world, there is one criminal more reprehensible than another, it is he who sins against great light and under the smallest temptations,—and, of course, the hottest wrath of an incensed community is kindled against him.
At the bar of yonder courtroom stands a youth with an aspect and manner indicative of culture and refinement far above those of the common herd of criminals. He was detected in the very act of committing a grave criminal offence. He has been educated under good moral influences, and possessed a patrimony that supplied every reasonable want. No looseness of living, no violent passion is alleged against him, and no adequate motive appears for the act. For a year or two past he has been unusually restless by day and by night, has slept poorly, and his countenance has worn an expression of distraction and anxiety. Various little details of conduct are related of him, which, though not morally censurable, were offensive to good taste and opposed to the ordinary observances of society. His friends are sure he is not the man he once was, but no expert ventures to pronounce him insane. Looking behind the scene, the mystery clears up, and we behold only a simple operation of cerebral dynamics. A glance at the family-history shows us a great-grandfather, an aunt, two second-cousins, and a brother unequivocally insane, the father and many other members widely noted for eccentricities and irregularities of a kind scarcely compatible with the idea of sanity. Considering that the brain does not spring out of the ground, but is the final product of all the influences which for generations have been working in the cerebral organism, it is not strange that the quality of his brain became so vitiated as to be incapable of some of its highest functions.—Looking a little farther back in our forensic experience, we behold a youth scarcely arrived at the age of legal majority, with a simple, verdant look, arraigned for trial on the charge of murder. He was the servant of a farmer, and his victim was an adopted daughter of the family, and some years younger than himself. One day they were left together to take care of the house, a little girl in the neighborhood having come in to keep them company. While engaged in the domestic services, quietly and pleasantly, he invited his companion to go with him into another room where he had something to show her, and there, within a few minutes, he cut her throat from ear to ear. He soon came down, told what he had done, and made no attempt to escape. They had always been on good terms; no provocation, no motive whatever for the act was shown or suspected. When questioned, he replied only,—"I loved her, no one could tell how much I loved her." He had been drinking cider during the morning, but his cool and collected manner, both before and after the act, showed that he was not intoxicated. His employers testified that they had always found him good-natured and correct, but considered his intellect somewhat below the average grade. A few months subsequently he died in jail of consumption. Regarded from the ordinary moral stand-points, this was a strange, an unaccountable, a monstrous act, and we are unable to take the first step towards a solution of the mystery. Looking, however, at the material conditions of his affections, his propensities, his impulses,—his cerebral dynamics,—we get a clew, at least, to the secret. His father was an habitual drunkard, and a frequent inmate of the poor-house. He had two children,—one an idiot, and the other the prisoner; and the mental deficiency of the former, and the senseless impulses to crime manifested by the latter, were equally legitimate effects of the father's vice.—Here, again, is one who might justly be regarded as a favored son of fortune. Fine talents, a college-education, high social position, an honorable and lucrative business in prospect were all his; but before leaving college he had made considerable proficiency in lying, drinking, forgery, and hypocrisy, besides evincing a remarkable ingenuity in concealing these traits. His vices only increased with years, notwithstanding the various parental expedients to effect reform,—a voyage to sea, establishment in business, confinement in a hospital for the insane, a residence in the country, a settlement in a new territory. All this time his intellect was cool and clear, except when under the influence of drink, and he was always ready with the most plausible explanations of his conduct. At last, however, delusions began to appear, and unquestionable and incurable insanity was established. The philosophy of our times utterly fails to account for a phenomenon like this. Had the hand of the law been laid upon him for his offences, he would have been regarded as one of those examples of depravity which deserve the severest possible punishment; and when the true nature of his case appeared at last, doctors only wondered how so much mental disorder could happen to one whose progenitors were singularly free from mental infirmities. In noticing the agencies calculated to vitiate the quality of the brain, we mentioned the neuropathies as among the most efficient, though their effect is chiefly witnessed in subsequent generations, and the present case is an illustration of the fact. His mother was a highly nervous woman, and for many years a confirmed invalid.