prove what an ordinary witness can, nor would he be allowed to, if no reason of a scientific character existed to justify it. ecessary fo Eiency in testify. A illed like But, on the other hand, when he takes his place as an expert before a court, a legal paradox is instituted in his behalf, by which he is allowed to testify, not to what he knows, but to what he believes, or forms an opinion upon, based necessarily on probabilities of analogy as well as experience. His testimony becomes a generalization of facts, by means of which he undertakes to explain certain phenomena, or particular instances, as deductions from a law of common authority and government over such facts. He first generalizes, and then abstracts, and his opinion expresses the degree of agreement between a general law and the particular subject of its authority. And inasmuch as, in the government of the physical universe we have constantly disturbing forces to modify the action of individual laws, there will ever be innumerable instantia migrantes upon which to posit exceptions, and thus complicate the problems given him to solve. It is the best test of the value of his experience, that he is able to discover the seminal principle involved in the inquiry, to trace it through the most devious ramifications, recognizing its centric power through all external forms of expression, and, by a process of mental chemistry, analyzing all its combinations both quantitatively and qualitatively. Through such steps alone can he rise to a satisfactory interpretation of the phenomena of nature. be should. and the ap § 101. In view of the immense erudition required to make a skilled witness in medicine, it follows that the high and responsible position occupied by the medical expert before courts of justice renders it indispensably can, nor would he tific character existed to necessary for him to possess the greatest measure of proficiency in those matters about which he is called to testify. And though he need not be a schoolman, nor skilled like a lawyer in dialectics and rhetorical fencing, he should, at least, be able to distinguish between the real and the apparent, in those physical phenomena specially appertaining to that human nature of which he is the accredited minister and interpreter. Much of that wrangling over the taking of skilled testimony before courts, which constitutes the opprobrium of so many trials, may be attributed to a want of precision and candor in putting questions, and the consequent inability of witnesses to answer them clearly. When a witness can not so interpret the gist of a question to himself, as to comprehend the pivotal point of the inquiry, he can not answer it lucidly. He may give a constructive answer in very nearly the same words addressed to him. But this is answering the letter only of the inquiry, or following the lead of his interrogator, not expressing his own ideas, which, when a skilled witness, it is plain he was specially called to unfold. There being always an arrierè penseé to every question put by counsel, while the expert is confined to direct answers, his manner, whether brief and outspoken, or halting and ambiguous, is ever liable to be misinterpreted, according as it approximates to, or departs from the point intended to be reached by his examiner. en he takes his place legal paradox is ins is allowed to testify, n he believes, or forms 21 n probabilities of analy timony becomes a gene which he undertakes t particular instances, & n authority and gover st generalizes, and the sses the degree of agres | the particular subject of in the government of the stantly disturbing force: al laws, there will evet tes upon which to posit the problems given him the value of his experi the seminal principle in through the most devious ntric power through all , by a process of mental binations both quantita gh such steps alone can tation of the phenomena se erudition required to cine, it follows that the occupied by the medical renders it indispensably § 102. There is on this account among physicians a great sensitiveness and reluctance about appearing before courts, for, besides being at times roughly handled in a cross-examination upon professional subjects by those of a different calling, their opinions are often disregarded by the jury, who pronounce a verdict directly antagonistic to the current of their testimony. To be summoned to express an opinion in a case, and yet not have that opinion form part of the purport of the judgment, seems to many little short of an insult. But this view involves an entire misapprehension of the duties and scope of testimony of an expert. He should understand at the outset that he is not called to express any opinion upon the merits of the case; that he has no proper concern in the issue, and by whichever party called, he is in no wise the witness, much less the advocate of that side. His testimony is invoked in almost an impersonal sense, to explain the relations of cause and effect in certain physical facts that are in evidence before the court, and which relations, being unintelligible to the jury, require professional explanation at his hands in order that due weight may be given to the facts out of which they arise. His duties are properly limited to gauging the value of certain facts as they appear in evidence-facts whose importance to the issue can not be determined without his assistance. diminish ei timony the And that the l who will Dowing ex But an opinion upon the relations of facts is not an opinion upon the truth of those facts. It is for him to decide the former; it is for the jury to decide the latter. For him to pronounce an opinion either upon the truth of the facts given him for interpretation, or upon the merits of the case, would be to usurp the province of the jury, and thus incorporate in his own person the functions of court, advocate, and witness. It is, therefore, from no desire tempted to 1 But here it must be observed that the witness can not in strictness be asked his opinion respecting the very point which the jury are to determine. For instance, if the question be whether a particular act for which a prisoner is tried were an act of insanity, a medical man conversant with that disease, who knows nothing of the prisoner, but has simply heard the trial, can not be broadly asked his opinion as to the state of the prisoner's mind at the time of the commission of the alleged crime, because such a question in $103. I pens that another, ea to the profession. confusionto make t to be rep than vict The testin branch of han a m cathedra judicial To bias dlogy, diced, 1 To be summoned to er lations of facts is not a • witness can not in strictness to diminish either the importance or the value of medical testimony that courts are compelled to adopt such rules. And that they are wisely conceived must be apparent to all who will pause to inquire what would be the effect of allowing experts to usurp power, which they might be tempted to use for the benefit solely of the party calling them. § 103. In the examinationn of experts, it often happens that neither counsel nor witness understand one another, each using terms of various signification, according to the import most habitually given them by either profession. This necessarily produces ambiguity and confusion-a condition not undesired by him who seeks to make the worse appear the better reason, but always to be reprobated in a court of justice, where truth rather than victory should be sought after. For these reasons the testimony of experts, constituting a most responsible branch of the law of evidence, since it is something higher than a mere oral recitation of facts, being an opinion ex cathedra upon the value of such facts, and thus quasijudicial, is jealously criticised to see that it is tainted by no bias towards either party. Under a distorted phraseology, the witness might easily be made to appear prejudiced, or, an undue emphasis placed upon a statement of subordinate consequence might elevate it into the sphere of a dogmatic assertion. Interpreting an idea as expressed through language, or construing that language volves the determination of the truth of the facts deposed to, as well as the scientific inference from those facts. Yet he may be asked what judgment he can form on the subject, assuming the facts stated in evidence to be true. Taylor's Evid. p. 945; R. v. Wright, R. & R. 456; Rex v. Searle, 1 M. & Rob. 75; Fenwick v. Bell, 1 C. & Kir. 312; Beckwith v. Syde botham, 1 Campb. 117; Collett v. Collett, 1 Curtis, 687; Malton v. Nesbit, 1 C. & P. 72; McNaughten's case, 10 Cl. & Finn. 200. technically and etymologically, instead of in its usual and § 104. Lord Bacon has well and wisely said, that "the greatest trust between man and man is the trust of giving counsel." And this trust may always be assumed to exist wherever special aid is given for the purpose of informing the judgment of others. It is not alone the province of lawyers to give counsel; physicians also, and any persons possessing special skill, may, and often do, act as such in trials at law, and their responsibility becomes none the less because that counsel is administered in the form of exacted testimony, rather than of spontaneous enunciation. Hence, testimony forming the evidence in every case constitutes its foundation. It is upon this alone that the issue is determined, and it is no wonder, therefore, that so much importance is attached to securing it as an unbroken chain of cumulative facts connecting the proof, as finally established, with the allegation as originally made. Remembering these things, we shall not blame lawyers for their zeal in keeping its links unbroken, or evincing heat in repelling attempts to break through it. "Maximus tamen patronis circa testimonia 1 Essays "Of Counsel." |