When the physician steps upon the witness stand he is where the domain of law and the domain of medicine overlap. He is in a borderland of joint jurisdiction. Each profession has its own system of applied logic. The logic of medicine is peculiarly adapted to investigation to guard against error in treating the sufferer. The law has its peculiar system of evidence to guard against error in seeking to punish those accused of causing the suffering.

These professions differ to some extent in their modes of investigation and in their principles of evidence. When the Law needs to determine a question of fact peculiarly within the domain of Medicine, it summons the physician to the witness stand, and in his examination the knowledge which he has acquired by medical tests and medical reasoning for the kindly purpose of succor and relief is subjected to the tests of caution and scrutiny which the Law has put as safeguards against the infliction of undeserved punishment, or the unjust deprivation of property and control. The habits of thought and the processes of reasoning of the trained physician are

adapted with the utmost skill to the immediate purpose for which they are employed. It is his duty to discern and act upon the slightest indications of danger; to draw inferences of precaution from undefined, sometimes almost undefinable, aspects. It is the duty of the law to hold back the hand of justice from acting upon slight suggestions, or even doubtful probabilities, and to discard all conclusions which are not forced upon the mind with the proper degree of certainty. It necessarily follows that with a physician on the witness stand in a well contested litigation, there is a collision between his free and direct methods of judgment and the exclusory rules, slow-moving inferences, and guarded recognition with which he is

met.

There is another peculiarity in the situation of the medical witness, when he is called to testify to what he knows of or through a person who was his patient : his professional services are in their nature confidential, and their usefulness and success depend largely upon the freedom with which the patient discloses everything relating to the present condition and its

antecedents. When the physician is called as a witness to facts connected with one who is, or once was, his patient, the situation invites questions that break through this confidence.

Whatever is peculiar in the restraints or embarrassments of medical men when acting as witnesses is due to one of these two causes the difference between what I may call the Logic of the Law and that of Medicine, and the attack of the lawyer on the confidences between the physician and his patient.

I. THE PHYSICIAN AS AN EXPERT

WITNESS.

The first of the difficulties I have mentioned characteristically belongs to the examination of the physician as an expert. The second to his examination as an eyewitness, his examination as to things seen and heard in his intercourse with a patient.

Let us consider the bearing of the principles I have mentioned upon these two situations.

The physician as an expert, besides finding that his methods of reasoning are in collision with those of the law, is met with the same liability as all expert witnesses to the imputation that his opinions are influenced by his fee. This characteristic weakness of expert testimony has very recently been emphasized anew in the Court of Appeals. PECKHAM, F., said, a few months ago in Roberts vs. New York Elevated R. Co., 128 N. Y., 464: "Expert evidence, so called, or, in other words, evidence of the mere opinion of witnesses, has been used to such an extent that the evidence given by them has come to be looked upon with great suspicion by both courts and juries, and the fact has become very plain that in any case where opinion evidence is admissible, the particular kind

of an opinion desired by any party to the investigation can be readily procured by paying the market price therefor. We have said lately that the rules admitting the opinions of experts should not be unnecessarily extended, because experience has shown it to be much safer to confine the testimony of witnesses to facts in all cases where that is practicable, and leave the jury to exercise their judgment and experience on the facts proved. As is stated by EARL, F., in Ferguson vs. Hubbell (97 N. Y., 507), 'It is generally safer to take the judgments of unskilled jurors than the opinions of hired and generally biased experts."

Occasional instances of partisanship have given rise to these and numerous similar animadversions. But expert opinion on scientific questions is found absolutely necessary to the proper administration of justice; and the purity and integrity of the great mass of such testimony maintains its position and continuous use in our courts, notwithstanding these occasional abuses and the undeserved suspicion which they throw over expert testimony generally, prejudice which enables counsel in almost any case either openly to make or covertly to suggest imputations on the good faith of such witnesses.

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It is doubtless impossible to avoid all occasion for such criticism, but two precautions would go far toward removing them.

First, an attorney having occasion to employ medical testimony should realize that if such testimony is to be of substantial value to his case, it must be above that suspicion; and testimony of that quality is to be ensured by realizing that he is not to pay for the forming of opinions, but for the service of a capable scientific man in attending on the trial and explaining those

opinions and their grounds to the court and jury. The expert himself should never forget that his strength as an expert depends on the fact that his opinions are not for sale, much less made to order. He is to speak the voice of authority in science, and his fee is the proper recognition of his mastery of science and of his labor in attending at the expense of other engagements and putting himself at the service of court and counsel for the purposes of the

cause.

This proper relation of counsel and expert is often, doubtless, embarrassed by the inattention of attorneys to the point. An attorney who applies to the proposed witness with an offer of a fee if he can swear to such and such conclusions, is almost sure to impede his own case with some flavor or suspicion of partisanship in the expert testimony. If, on the other hand, he first gets some competent friend conversant with the subject which is to be under examination, to ask the intended expert, not what his opinions are, but what are the scientific facts involved in the question concerned, he may indeed have to apply to more than one before he finds the requisite knowledge of the subject to confirm his view of the case; but when he does he will have a witness who is not only free from all imputation of having constructed his opinions for the purpose of the case, but what is equally desirable, he will have a witness who speaks with the confidence of science, absolutely free from the consciousness of being relied on as a partisan or even as a sort of medical counsel. The attorney should not undertake to instruct the expert. He should ask the expert to instruct him. When the expert has told us what we can prove, then we are to tell him how it is to be proved. An expert who is instructed as to what he is wanted

to prove, before he is retained, is half spoiled in the retaining. And he may generally be expected to complete the spoiling on the stand. A medical expert may properly be employed in investigation of a new question, to ascertain what are the conclusions to which science will lead him. But to attempt to retain one as a witness to find reasons for coming to a prescribed conclusion, is to attempt to corrupt science, and can rarely succeed with the cause, for it never will corrupt any one but a quack, and only embarrass a good witness whose honest opinion is favorable. The question with which to approach a proposed witness, therefore, is not whether he will testify on such a side in such a case, nor even whether his opinions are favorable to that side; but what is the scientific doctrine in such a case. Not until we find that there is some scientific possibility or impossibility in our favor do we want any expert.

In the second place the expert should feel at liberty to look at the case rather as a judge than as counsel. In the courtroom the medical witness is between the judge and the counsel. It is the true policy of counsel to make his own relation with his expert witness such that the witness may lean not toward counsel, but rather toward the judge, and thus secure for his expert testimony the weight which scientific truth clearly explained will command. It is a common error of our profession to allow our expert to lean toward counsel, and thus cast even upon an actually unbiased scientific witness, the suspicion of being an associate counsel in disguise. Few men who have not watched with care the work of juries and the common disposition of jurymen, realize how much the weight of testimony of a witness who is put forward as disinterested, is im

paired by anything which appears to identify the feelings of the witness with the party for whom he is called, or to show a disposition on the part of the witness to favor the case of his examiner. An expert witness ought not to be put in a situation where he can be influenced, either by such a disposition or to avoid the appearance of it.

A medical witness who avoids a false appearance of partisanship is free to give effect to the suggestion I have already made, as to the distinction between medical and legal usages of reasoning.

If a capable expert witness with strong convictions proves to be weak or produces a weak effect upon the jury, it is usually because he does not get farther than the expression of mere opinion. The strength of a medical witness is not in the confidence of his opinions, but in the intelligible reasons he is able to give for them. The cogency of expert testimony depends on moderate opinions, clearly supported, by reasons intelligible to the jury. Of course upon many subjects the jury may not be capable of understanding, in a scientific sense of that term, the reasons for an opinion; but they are very quick to feel the difference between an opinion for which the speaker can state clearly reasons the character of which is intelligible in a popular sense, and one who has an equally confident opinion but is at a loss to make it clear that he has good reasons. Next after the obvious non-partisanship of which I have spoken, clearness and lucidity in describing such matters as the jurors can distinctly conceive, appear to be important, with the ability to give strong reasons, intelligible if possible in detail, and if not, intelligible at least in nature, for the conclusion arrived at. And lastly should be mentioned the freedom to make frank

statement of the existing scientific doubts or uncertainty regarding any of the nonessential points in the case.

The importance of giving reasons for an opinion, is one of the two chief points at which the methods of the law are at variance with the methods of medical science. The physician must act on doubt, the law must not. If the diagnosis hesitates between two diseases, the symptoms being ambiguous, the physician it is true may try to hit both. But his duty, as well as his effort, is to form a judgment based not alone upon clearly definable reasons, but upon the combined results of his own acuteness and experience, discerning aspects which he is at a loss to characterize as symptoms, or even to analyze and distinctly describe. That indeed is his genius, the genius of insight. To be able to discern,-to interpret conditions that he cannot describe adequately,-to form an acute and practicable opinion when all known and describable symptoms are ambiguous, is among the highest gifts of the medical profession, and in practice that ability is of the very first value. The characteristic strength of an expert witness requires the added ability of power to analyze that which others have not so well analyzed, and to give clear and intelligible reasons where others perhaps equally capable of forming a correct opinion can give only the opinion without satisfactory

reasons.

It is precisely this ability and the powerful instinct of duty which insight into a case arouses, that cause the greatest embarrassment to the physician on the witness stand. It makes him want to cover the whole ground with an instant opinion that ought to end all controversy. He is impatient of the lawyers' questions that move on step by step, and short steps at that.

It is galling to him who is full and overflowing with the scientific view of the whole thing, to be told to answer yes or no, and to have whatsoever is more than that struck out with a rebuff. Now I will not undertake to say that a better system of judicial investigation of scientific questions is not feasible; but so long as the present system continues, this annoyance will continue to distress every expert who wishes to proceed by the methods of his own profession in giving judicial evidence. If he wants to decide the cases he should run for judge. If he is only a witness he has no business to try to decide the case. A simple suggestion will put the expert witness quite at ease. Answer yes or no to every question that can properly be so answered; and remember that you will have opportunity to explain whatever in your testimony is necessary to explain; and do not volunteer wisdom that is not asked for.

The reason is that in the administration of justice the experience of mankind has shown the absolute necessity of a division of labor that does not exist in the medical practice. We have a judge whose business it is to preserve order and lay down the law; a sheriff whose business it is to execute the sentence. The judge may be privately convinced that the accused is guilty, but he has no business to sentence him if the jury acquit him. And if the case is properly left to the jury, and they lawfully convict him, the judge would be recreant to his duty to refuse to enter the verdict because his opinion was the other way. The sheriff is bound to execute the sentence, or to let the prisoner go free, irrespective of his own opinion, no matter how clear. And if the judge or jury should undertake to execute the sentence because the sheriff would not, they would be tres

passers, and if they inflicted death would be murderers. The attorney has no more business to decide whether his client is guilty than he has to usurp the office of the judge. The man is to be tried to ascertain guilt. If it was right for an attorney to decide that his client was guilty, there would be no need of judges and juries. He and the sheriff could attend to the whole business. This is not the place to explain the reasons for this. But the fact is so ; and no witness can be comfortable on the stand who thinks it necessary to do that which he cannot do, and ought not to be allowed to do. He is there simply to furnish such information as the law asks for. If he wants to do more, he mistakes his function, and is in a very uncomfortable position.

Nowithstanding the friction which is caused by medical experts' repugnance to legal methods of investigation, the value of their aid in the administration of justice is only exceeded by the value of the combined methods of both professions in instructing the public mind on scientific subjects.

If I were asked to name the three great classes of educational institutions in this country, I should say the common school system, the collegiate or university system, and the jury system. The value to the country of jury trials has never yet been estimated. The most intelligent men in a great city like this are but occasionally reminded of this function by trying to evade the summons to jury duty; but throughout the country it brings business. men and wage-earners generally in turn month after month, into the court-room, to see what kind of a judge is exercising judicial power, and how he does it; what kind of a district-attorney the county has elected; to hear discussions about contracts, and