# Popular Science Monthly/Volume 26/March 1885/Medical Expert Testimony

Layout 4
* MEDICAL EXPERT TESTIMONY.
By FRANK HASTINGS HAMILTON, M. D.,
CONSULTING SURGEON TO BELLEVUE HOSPITAL, ETC.
FROM time to time within the last few years, and perhaps for a longer period, comments have been made in the daily secular press, and occasionally in the medical journals, in reference to the testimony of medical experts, which were anything but flattering to medical men. These comments have, in most cases, had reference to their testimony as experts in cases of alleged lunacy, or in cases involving the question of moral responsibility. They have been charged with ignorance, incompetency, inconsistency, and in some cases with venality. It has been said that their opinions are purchasable.
In support of these grave charges the reader has been referred to the fact that an equal number of eminent experts can usually be found to testify on either side, and that in their testimony they often differ from each other irreconcilably. In other cases no evidence is offered to sustain the charges, except the fact that the opinions of the writer and of the public differ from that of the expert.
In what I shall have to say upon this subject I propose to confine myself to those examples in which the question involved is one of mental capacity and responsibility, as being that in which medical experts have been most often and most severely criticised. To a certain extent, however, you will observe that the arguments employed will apply to expert testimony in any other department of medicine or of science.
1. Medical men, whether they be specialists in the study of mental diseases or not, in the differentiation of the class of diseases now under consideration, labor under peculiar difficulties. There are many mental disorders which are unaccompanied with any recognizable abnormal physical conditions of the brain; that is to say, in which there are no structural lesions of the brain cognizable during life, or which can be satisfactorily demonstrated in the autopsy; and there are many in which the mental alienation can not be fairly traced to any lesions in any other part of the body. The number of these examples may hereafter be found to be smaller than is now known, but for the present the fact is as I have stated. That a functional disturbance of the brain exists in such cases is self-evident; but for aught we know this may be due to some slight molecular, chemical, or vital changes in the nerve-cells of the gray matter of the brain or of a group of cells, not denoted by any peculiar physical signs during life, and which can leave no possible traces after death. To cause mental ​derangement, it may be only necessary that these microscopic cells should be temporarily deprived of their normal supply of oxygen through the vascular system; or, on the other hand, a slight increase in the supply of the proper nutriment or stimulus may cause the same results. A simple loss of equilibrium, or change of tension in the nerve-cell, may cause delirium. These abnormal physical conditions may be temporary or permanent, but in either case they will probably, in the future as in the past, elude the most careful observation of the physician, the chemist, and the microscopist. Science has calculated the vibrations of the musical chord, and measured the oscillations of a ray of light, but has not estimated the vibrations of the living intellectual nerve-cell, nor analyzed its aura which waits incessantly and instantly upon its will. It has furnished no means, therefore, of determining mathematically when the mysterious organ of the mind is out of tune, or why its notes are discordant.
2. Hitherto no one has furnished a definition of insanity which will cover all of the supposed examples. Nor, considering the nature of the subject, is it probable that it will ever be done. It may be easy to differentiate a certain class of cases. We can say, without fear of contradiction, that a raving and uncontrollable maniac is insane, or that another, whose life has been uniformly consistent and harmonious, is sane. But this is not the class of cases in reference to which our opinions are asked. They do not give rise to litigation or dispute. Our opinions are only asked when there exists some room for doubt as to the exact mental condition of the person in question, and who therefore occupies a position near the border-lines which separate insanity from sanity; but no legal or scientific authority has established these lines. They are not indicated by broad rivers, or mountain-ranges, such as form the natural boundaries between nations; but the opposite conditions here become insensibly merged, in such a manner that no one can say where one ends and the other begins. One might as well attempt to determine the exact limits of the auroral lights.
Says Ray, in his classical treatise on "Mental Pathology," "One source, and perhaps the principal, of the prevalent error, is the habit of regarding insanity as a sharply defined phenomenon, easily separated from all accompanying incidents, like an earthquake or a chemical action, instead of a condition arising from obscure beginnings, culminating more or less rapidly, and declining by imperceptible steps, as the darkness of night is succeeded by the light of common day." In these doubtful cases the expert has to consider the possible motives of the individual, his hereditary tendencies, his education, social influences, his previous habits, his condition as to health or disease, and a multitude of other matters, all of which are to be carefully weighed and balanced against each other, before he can form a correct judgment as to whether a certain act or line of conduct implies insanity and irresponsibility or not. That there should not be exact, ​or, in many cases, even approximate concurrence of opinion among experts of equal qualifications, is natural and ought to excite no surprise. Those are the unreasonable persons who expect anything else. Of course, it is desirable that there should be no disagreement, since in the decision of so nice a question one grain of testimony, more or less, cast into either scale may decide the life or liberty of the person whose case is before the court; but for the fallibility of human opinions, at least to the extent now supposed, no remedy has as yet been provided.
3. If it be true that expert testimony, when questions of sanity or of moral responsibility are involved, is often contradictory and irreconcilable, it is equally true of expert testimony where questions of much less complexity are involved. It is true in nearly all cases of dispute upon matters of science, art, or commerce. In the Feuardent Di Cesnola suit we have seen one expert in archaeology affirm that a piece of statuary was as it came from the hands of the original artist, while another has declared with equal confidence that it was constructed from fragments obtained from different sources. In the investigation which followed the Ashtabula catastrophe, it was ascertained that one man, who was supposed to be both theoretically and practically acquainted with the construction of railroad-bridges, had declared this bridge to have been built according to the most approved system, and that it was perfectly safe, while another expert had expressed a contrary opinion; and this important question was left to be finally and definitively settled when the bridge had given way under the weight of a passing train, and twenty or more lives were lost.
Does it often happen, in any class of cases, that lawyers are unable to obtain expert testimony for their clients, in case they stand in need of it, or that the testimony on the two sides is not conflicting?
Not alone experts, but lawyers also, if we can accept their own statements, do not often agree in opinion as to the merits of the cases of their respective clients. The courts also are far from uniformity in their decisions and their interpretation of the law and the facts.
It has been asked, "If witnesses are not suborned, how does it happen that experts so uniformly testify in the interest of the parties by whom they are employed?" As if it were a question which admitted of but one answer, namely, that the witness gave his testimony under oath, only as a consideration for the pay he was to receive, and without regard to the sanctity of his oath, or to the value of his reputation as a citizen and a man of science.
This question, asked no doubt seriously, will be answered seriously: Because no intelligent lawyer would call an expert witness to the stand until he had ascertained, after a full statement of the case to him, what his opinions were. He would not summon a witness who would certainly, or even possibly, damage the cause of his client.
It is fair to conclude, from the preceding statement of facts, that ​the supposed evils of the present system of procuring expert testimony in cases of alleged lunacy have been greatly exaggerated, if they are not wholly imaginary. Such cases are not decided by the experts. Having given their opinions under a direct examination, they are subjected to a sharp cross-examination by skillful attorneys, who subsequently, and after sufficient time has been given for study and reflection, are permitted to argue the case to the jury. The judges comment upon the law and facts relating to the case; and, finally, the jurors, rendered thoroughly familiar with all the points in dispute, and acting independently, render the verdict: and they are better able to do this intelligently than they would have been if there had been no discussion.
It is evident also that the supposed evils are not limited to one, but that they extend in an equal degree to all other classes of expert testimony.
Those who are of opinion that the evil is actual and serious have from time to time suggested various remedies.
It has been suggested that experts should be appointed as advisers to the courts, by the State or municipal governments.
Against this method lies the grave objection that the public can have no assurance that the best men would be chosen. The appointing power might be influenced by personal or political motives, rather than by the acknowledged fitness of the person chosen; and it could provide for experts in only one class of cases, since no man could be an expert in all cases in which his services were required.
If it is proposed that the courts should themselves, as occasion might arise, make the appointments, the method would still be liable to the objection that even the courts could not always be relied upon not to make choice of improper men, either because they were uninformed, or entertained personal friendships.
To a certain extent, in cases where the ends of justice plainly demand the exercise of this authority, the courts, or the attorneys who officially represent the courts or the Government, are, under existing laws, permitted to summon expert witnesses; and, in the narrow limits within which this power is now authorized and exercised, it can do no harm. It is only against the exercise of this authority as an exclusive or even general mode of obtaining expert medical testimony, that I desire to record my protest.
In whomsoever the power to make these appointments may be vested, and in whatever manner it may be exercised, and whether the experts may be subject to cross-examination or not, in either case it seems to me liable to work injustice. It happens often that the accused comes into court under the imputation of a verdict of the coroner's jury, and under the adverse influence—more or less—of a presentment or indictment of a grand jury, both of which may be, and usually are, based upon ex parte testimony. The State or district attorney is ​the representative of these preliminary courts in the prosecution of the accused, and he has already prejudged the case.
It would seem that the State has—in these manifest advantages—all the ex parte aid to which it is entitled, or which the ends of justice demand; but if we now add the testimony of an expert, perhaps not subject to a cross-examination, who has received his appointment from the State or court, and the opinions of the expert chance to be adverse to the accused, the latter enters upon his defense with the additional disadvantage of his case being probably prejudged by the court as well. Thus heavily handicapped, his chance of making a successful defense must be very small indeed.
This method of securing expert testimony seems to me also contrary to the spirit and genius of our institutions, but in harmony with the institutions of the greater part of Europe, where the tendency of governments to concentrate power in themselves, and in the courts, as instruments of the governments, is known and admitted.
In our system of jurisprudence and, I may say, in the Anglo-American system, the personal rights of the citizen are as carefully guarded as those of the State. In the present case the State has certainly its equal share of protection, and by the proposed change it would have more than its just share.
I make no reference to the other means provided by the State for the determination of questions of insanity, such as commissioners in lunacy, etc., because they are in no way connected with the matter now under consideration, namely, the proper method of securing testimony in courts of law.
During my temporary residence in Paris, in 1844, it was a matter of common remark, among medical men and medical students, that Orfila, the celebrated chemist, and the official adviser of the crown in certain matters of expert testimony, had committed a great blunder in a recent case of supposed poisoning by arsenic, and that the error had been detected and exposed by a member of the Academy of Medicine, but that the disclosure of the error came too late to remedy the injustice and harm it had done. He was charged with having been the instrument of like injustice to others, and was frequently spoken of as the "king's executioner."
I do not relate this as reliable history, but only as my recollection of the common gossip of the day; but, whether the accusations were true or not, they were plainly such as might reasonably be made and justified under a system of jurisprudence in which the professional expert is an appointee of the crown, and is regarded in the light of an official adviser.
In some cases which have come to my knowledge the public has seemed to form its opinion as to the nature and value of the expert testimony solely from the verdict rendered by the jury. In the case of The People against Cole, tried at Albany in 1868, Judge Hogeboom ​presiding, the jury rendered a verdict of acquittal on the ground of unsound mind; but no medical expert had testified that Cole was insane. In the course of my examination as an expert witness, the court asked me whether I thought "that Cole, at the time he committed the act for which he was under trial, knew the difference between right and wrong, and that the act was in violation of the law." To which I replied in effect that "Cole, being suddenly confronted by the man who had wronged him, did not probably consider whether the act which he was about to commit was in violation of the law or not." If the jury made use of this reply to pronounce him insane, the responsibility of their verdict does not rest upon me. Their verdict of "unsound mind" was given, as it has been in many similar cases, because they did not think he ought to be punished for the act, and they were quite willing to give a very broad and partial interpretation to any testimony which in the remotest degree seemed to favor the defense. Subsequently, from several sources, I learned that my testimony, inferred only from the verdict, had been subjected to criticism.
The question put to me by the judge, although not so broad as it is usually made, no doubt had in view the legal definition or tests of unsound mind, and which, with a few slight modifications, has been incorporated into most systems of jurisprudence. But no legal definition of unsound mind can ever be properly made; and for the simple reason that no scientific definition is possible. The latter fact has generally been admitted by writers upon mental disease; but, nevertheless, they have often attempted to make what they are. pleased to term approximate definitions, for the purpose, as they have declared, of furnishing at least a guide in the proper direction. Upon these approximate definitions the law-makers have constructed their legal definitions or tests; no longer intended as guides simply, but as authoritative and sharply defined distinctions, which the courts are compelled to recognize. Whether these tests be applied in a scientific or legal sense, they are in my opinion unsound, unjust, and confusing; they are calculated to mislead the judgment rather than to direct it to a proper conclusion. They ought, therefore, to be abandoned, and the whole matter left to the common sense of the jurors, aided and enlightened by the testimony, the arguments of the counsel, and the exposition of the courts.
4. While, in what I have said, I trust I have shown a purpose to defend my professional brethren, when appearing in the rôle of experts in lunacy, against unjust criticism, by maintaining the undeniable proposition that, other things being equal, they are the most trustworthy witnesses, I am at the same time prepared to say that they are not the only persons or classes of persons whose opinions as experts may be valuable in matters of this sort, or whose opinions might not, in some cases, be safely substituted for their own.
In reference to questions of sanity or insanity, most men of ​intelligence who have reached adult life are experts. It is, with all of us, the daily practice of our lives to observe and study men's conduct and motives, and we are quick to discover the smallest evidence of mental unsoundness, especially in those with whom we have intimate personal acquaintance. Indeed, in most cases the mental alienation is suspected, or well known, long before the case is brought under the notice of the alienist.
It is not the same, however, in reference to most other subjects in which the services of experts are demanded. It is not so in most matters pertaining to either science, art, commerce, or the general business of life; in all of which the average citizen is presumably without experience or knowledge, and without the aid of the expert he could not intelligently perform the duties of a judge or of a juror.
If the question involved were one of mineral or vegetable poisoning, the trial of the case without the assistance of a practical chemist would deservedly expose the court and the law to public contempt.
If, again, it were a question whether the neck of the thigh-bone had been broken within or without the capsule, involving, as this question does, in a great measure, the degree of permanent injury which the patient has sustained, without the aid of an experienced surgeon it would be impossible to place the case fairly before a jury, not one of whom, probably, had ever seen either accident, or knew that they were not identical.
Finally, there is reason to fear that in one direction professed alienists are more liable to err than most other men of learning and experience, but who have not confined their studies so exclusively to the specialty of mental diseases.
It is a fact of common observation that, in all departments of medical science, the specialists to whom our science is indebted for some of its most important improvements and discoveries, are inclined to extend the range or number of diseases and of sympathies referable to the organs of whose lesions they have made a special study. This they do conscientiously, sometimes wisely and sometimes unwisely—their errors being exposed when some other specialist traces the functional disturbance to a lesion of some other organ, or the general practitioner demonstrates that all or nearly all the organs of the body are suffering from a general dyscrasy, and that the lesion of no one in particular can fairly be held responsible for the particular symptoms in reference to the cause and treatment of which the specialist is consulted.
Alienists need to be reminded that they have shown the same tendency to increase the number of diseases under the title of insanity, and to widen the range of their specialty, by including a great many eccentricities and moral obliquities under this title; and that by so doing they have virtually relieved the subjects of these peculiarities ​from responsibility. This is seen in the adoption of the terms monomania, moral insanity, insane impulse, insane delusion, and in the additions made from time to time by writers to the varieties of monomania, among which are placed kleptomania, pyromania, erotomania, theomania, dipsomania, homicidal mania, suicidal mania, etc.
Spitzka, in his recent treatise on "Insanity," which work has at once taken rank among the highest authorities upon this subject, speaking of monomania, says: "Here those alienists who delighted in burdening the infant science of psychiatry with new systems of classification, found a fruitful field for innovation. Whatever the direction in which a lunatic manifested his most prominent symptoms, that direction determined the coining of a new term. . . . The designations 'Gamomania,' or 'the insane desire to marry,' or 'Frauenschuhstehlmonoraanie,' or 'the mania for stealing women's shoes,' are imperishable monuments of this folly." To which judicious remarks I will add that, if such acts or mental conditions are to constitute a basis for the classification of insanity, I see no reason why it should not extend to every faculty, sentiment, or emotion of the mind, and to every act of eccentricity or of viciousness which disfigures human conduct.
Rush, the author of "Medical Inquiries and Observations on the Diseases of the Mind," has been quoted as having said that all men were insane on some subject. To the same conclusion it would seem that certain alienists are inclining. If this be true, then the whole matter we have been considering becomes greatly simplified. All men are insane, and all are irresponsible.
It would be unjust to Dr. Spitzka, in whose opinions I have expressed a concurrence, as well as to myself, if I did not state that Dr. Spitzka is willing to retain the name monomania when the use of the term is accompanied with certain reservations and restrictions, "with the limitation that the prefix shall be understood to denote that the insanity extends in a special direction across the mental horizon." He justifies the continued use of the term, but not its abuse.
It is upon this point alone that our opinions diverge. I can not think it advisable to retain the term monomania, or any of the subordinate terms, either for purposes of classification or for the convenience of clinical description. Most alienists are agreed that, even when they use these terms for classification, they do not mean to say that the subject is insane upon only one point, but this is exactly what the term means, if it means anything. It is true that different alienists offer different explanations or definitions of the term, but nearly all admit that it does not mean insanity upon a single subject; and every one must have seen that, with or without explanations, the use of this term by writers and by expert witnesses renders it difficult, if not impossible, for the reader, the public, or the jury to distinguish in many cases between acts of moral obliquity, eccentricity, or viciousness on the one hand, and actual insanity on the other; between responsibility ​and irresponsibility. By the multiplication of terms of uncertain meaning they have darkened counsel.
It is liable also, in my opinion, to the further serious objection that it influences, unconsciously but perceptibly, certain alienists to extend unreasonably the limits of the term insanity. I am at least certain that, in this regard, it works mischief in its influence upon the people at large, among whom the word kleptomania and other analogous terms introduced by writers upon mental diseases are in common use, and by whom in most cases they are employed as an apology for crime. I would prefer, therefore, when a man steals and his conduct in other matters shows that he is of unsound mind, that he should be called insane, and not a kleptomaniac; but if he steals, even where the motive may not be apparent, and in all other respects his conduct is consistent, and his mind appears sound, it would be better both for the interests of science and of society that he be called a thief.