actual facts upon which the issue turns; then he is able to testify to them as well as to his inference from them and he may be therefore both a common and an expert witness in one. But it is not as a witness of facts at all that his position is peculiar; it is because as an expert witness he is allowed to testify to his conclusion from the facts, which he has either himself observed or which are in evidence from the testimony of others. His position is only peculiar in that a common witness is forbidden to testify to conclusions, and the history of the origin of expert witnesses must necessarily be simply the history of the exception in his favor to the rule that witnesses shall testify only to facts and not to inferences. This is better explained by considering briefly the rise of the rule as to conclusions. It is common learning to-day that originally and indeed for many years the jury had no witnesses present before them at all. They went about before or during the trial informing themselves as they might of the facts at issue. Not until the middle of the fifteenth century was even the practice of summoning witnesses well settled as an incident to the trial, and it was still later that any compulsory process became available.* That the rules of evidence are merely certain regulations to govern the evidence which the jury shall hear and that they are the offspring of the judicial control of the verdict, Mr. Thayer has made entirely clear. But these rules grew up but slowly and through the decision of judges, gradually eliminating certain material from the mass of what witnesses might say in court. The rule that a witness shall not testify to mere opinion or conclusion is such a rule and its origin no doubt was, if we could trace it, due to a gradual recognition by successive judges of the advantage of curtailing the trial and simplifying the issue by leaving out redundant matter. I call this redundant because in fact the opinion of the witness upon the issue can have no useful bearing on the case, and trenches on the jury's function. It is the jury that should form the opinion, make the conclusion and say truly-vere dicere-the fact, not the witness; he merely says what he knows. Therefore this rule of evidence-if in view of this it may be properly called such,-is somewhat different from those Mr. James B. Thayer, in his "Preliminary Treatise on Evidence at the Common Law," pp. 122-136 concludes that the practice became established about the middle of the 15th century, though it remained an unimportant incident of trials for some time thereafter. which shut off certain facts actually probative of the issue. Moreover, it was recognized comparatively early in the history of rules of evidence. For we find Vaughan, C. J., that great defender of the right of juries to go "on their own knowledge," well saying in Bushell's case in 1671.* "The Verdict of a Jury and Evidence of a Witness are very different things, in the truth and falsehood of them; a Witness swears but to what he hath heard or seen, generally or more largely, to what hath fallen under his senses. But a Juryman swears to what he can inferr and conclude from the Testimony of such Witnesses by the act and force of the Understanding, to be the Fact inquired after, which differs nothing in the Reason, though much in the punishment, from what a Judge, out of various Cases consider'd by him, inferrs to be the Law in the Question before him." The distinction cannot be put more plainly Yet in 1622 it had been said thatf a witness could testify to the very issue involved, that he knew it to be true, if another testify to the circumstances in detail; i. e., the conclusion of the witness upon the very issue is admissible if supported by other evidence. I cannot find any other cases in the seventeenth century which seem to illustrate the rule that the conclusions of a witness are inadmissible as such. The rule would seem to be one obviously necessary early in the history of the control by the courts of trials, and it is very likely that many cases exist which illustrate the rule, but I think it may fairly be said that in Vaughan's time the citation above quoted shows that the rationale of the rule was well grasped, even if it was not always enforced. As to the exception to the rule in favor of expert witnesses, of course that could not exist until the rule did, for if the exception proves the rule, a fortiori the rule is a condition to the existence of the exception. I can therefore only cite several cases in which expert witnesses did testify finishing by some cases where their testimony was consciously admitted by the court as an exception to the rule regarding conclusions. In Alsop v. Bowtrell, 1620, certain physicians testified that it might well be that a woman bore a child forty weeks and nine days after her husband's death, and yet it be his child, for the time might be delayed by ill usage and lack of strength. And so the *Vaughan, 142, 22 Car 2. +Adams v. Canon, Dyer 53b, note. +Cro Jac. 541. court, agreeing with the physicians, delivered to the jury that it might be so. The case involved the legitimacy of the child. I think it should be noted in this, the first case which I have found of real expert testimony,-by which I mean a case where the conclusions of skilled persons were submitted to the jury, that the witnesses are not stated to have been called on either side; and from the meagre report we have, they seem to have satisfied the court in the first instance of the truth of their conclusion before the evidence went to the jury. The court finally found the general proposition to be true and delivered it as datum to the jury to use in their final conclusion. In the Witches' case* in 1665 Dr. Brown, of Norwich, was desired to state his opinion of the accused persons and he was clearly of opinion that they were witches and he elaborated his opinion by a scientific explanation of the fits to which they were subject. It did not appear in this case by whom Dr. Brown was called as a witness and his position is doubtful for our purposes, though he spoke of a question of fact. Rex v. Pembroke,† in 1678, is more instructive. This was a trial of murder and the question was up as to the real cause of the deceased's death. Physicians were called on either side who testified under the examination of the attorney for the prosecution,or of the prisoner, both as to what were the causes of certain symptoms observed upon an autopsy they had seen and as to the general proposition as to whether a man can die of wounds without fever. It is true that the court took a hand in this evidence, but that is common enough to-day, and the only striking feature of the whole matter is in the fact that no one seemed to think it unusual. We must conclude from this that the rule excluding the conclusions of witnesses was not enforced often enough to make such a violation worth notice. The same kind of case is found in the following year in Rex v. Green, where a physician is called for the prosecution and testifies that the deceased could not have died from certain wounds upon his body as they gave no blood, but that he must have died from being strangled. Still another case of the sort is Rex v. Coningsmark,§ in 1682. #6 How. St. Tr. 697. t6 How. St. Tr. pp. 1337, 1338, 1340, 1341. 17 Howell State Trials, 185, 186. Howell State Trials, 21 In Spencer Cowper's case in 1699 the question was whether the deceased had been drowned. Certain surgeons testified that they had examined the body and found no water in it, so that it must have been dead when it entered the water. Other surgeons answered in general to certain hypothetical questions as to whether a drowned body full of water would sink. In addition sailors who had been in sea fights testified to the same questions, an interesting addition which would hardly be allowed to-day. In the eighteenth century the practice was certainly well established and numerous instances of it can be found.t In Rex v. Heath, 18 How. State Trials, 76 (1744), the court made a remark which is certainly significant of the general rule though the exception to it was not noted. The trial was for perjury upon a former trial in ejectment, in swearing that Lady Altham had never had a child. The witness had testified that he had seen Lady Altham at one time with a "big belly." The counsel then asked (76) "What do you apprehend became of that big belly?" On objection the court (Irish K. B., Marley, C. J., Ward and Blennerhasset, J. J.) said: "The apprehension of a witness is asked where no other evidence can be had in capital cases; as where a witness is produced to prove a wound given, he is asked whether, he apprehends that wound was the cause of death. That must be asked, for he cannot tell otherwise. It is the best evidence that can be had in that case. But as to a fact, if you make the apprehension of a witness necessary, it takes away all proof of fact." I confess that the last sentence is altogether enigmatical to me, but as to the first it shows that conclusions were as nearly “inadmissible" as was at that time known. Because it must be remembered that all through the eighteenth century, the rules of evidence were unknown in the strictness that we apply them. Thus Baron Gilbert in 1760 lays it down that the only rule is that of 13 Howell State Trials, 1126-1135. + Below are the cases that I have been able to find from an examination of Howell's State Trials, the usual edition of 1824: this testimony was however as to Rex. v. Kidd, 14 Howell State Trials, 137 (1701). Rex. v. Heath, 18 Howell State Trials, 68, 69, 70, 71, 73, 84 (1744). Rex. v. Blandy, 18 Howell State Trials, 1138, 1139, Rex. v. Canning, 19 Howell State Trials, 523 (1754)- madness and was given by laymen. Rex. v. Byron, 19 Howell State Trials, 1207 (1766). Gilbert on Evidence, 2nd ed. London, 1760, passim. the best evidence the case admits, and he would even admit hearsay when "corrobative" and not given as sole support of a fact;* so also Buller's Nisi Prius.t Further we find in the trial of Lord Ferrers for murder in 1760 where the defense attempted was that of insanity, that the admission of expert evidence was already subject to a rule we are now thoroughly familiar with, and one, which presupposes, I think, considerable use of that form of testimony. Prior witnesses had testified to strange and supposedly insane acts of the defendant. A surgeon was then called and asked whether from all the facts he would say that the defendant was insane. The Crown counsel objected, and Lord Mansfield—the trial being of course before the Lords--directed the defendant that he might not put such a general question, but that if he would specify the precise facts, already in evidence upon which he wished to base the surgeon's opinion, he doubted not that the Crown would not object. Whereupon the defendant put a number of questions based upon specific acts already in evidence which the surgeon in each case-how history repeats itself!-testified were symptoms of insanity. To professional readers it may be in addition interesting to know that the jury, i. e., the Lords, seem to have preferred their own inference to the surgeon's and convicted the defendant. There are criminal cases, but in 1872 in a civil case before Lord Mansfield in K. B. § a new trial was granted, because of the exclusion of the testimony of engineers as to their opinion of the cause of the filling of a harbour, alleged to be caused by a sea wall, which it was the object of the action to abate on information as a nuisance. It did not appear in this case whether or no the engineers had personally ever seen the wall or its effects, though perhaps it is fair to presume that they had. This case is, I believe, usually regarded as the first in which the point was raised. In 1790, however, it was ruled by Lord Kenyon at Nisi Prius,¶T that experts might give what was merely opinion from facts in evidence, though Erskine, who was of counsel, took the point that their opinion was necessarily of less value than that of those who had seen the facts. *Gilbert on Evidence, p. 153. +Buller's Nisi Prius, p. 294b. Rex v. Ferrers, 19 Howell's State Trials, 942-944 Folkes v. Chadd, 3 Doug. 157. Thornton v. The Royal Exch. Ass. Co., Peake, 25 |
