The opinion
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Butzel, J.
I concur in affirmance, but 1 cannot agree with the proposition of my brother McAllister that because insanity is a disease and comes within the realm of medical science that only physicians are competent to answer hypothetical questions on behalf of a defendant in a criminal case. The law does not require a rule so formal, and I do not think we further the cause of justice by insisting that only a medical man may completely advise on the subject of mental condition. The proposed witness was a graduate of Tilton School in New Hampshire, Wesleyan University, Yale University; and Harvard Foundation, and held the degrees of Bachelor of Arts, Master of Arts, Bachelor of Divinity, and Doctor of Philosophy in Psychology. As a graduate student he had attended the University of California, Columbia University, Boston University, Harvard University Medical School, and the Boston Psychopathic Hospital. He was a full professor of Central College, Fayette, Missouri; Baker University; University of Kansas, and Michigan State Normal College; he had been connected with the latter institution for 11 years up to the time of the trial. He had given courses in normal and abnormal psychology, experimental psychology, educational psychology, mental tests and measurements, psychology and criminology, problems in marriage and family, and problems of child-welfare. One of his texts has been through five editions since the first publication in 1927. He has written articles on the subject of human behavior that have appeared in publications throughout the United States. He specialized in the particular field of psychology devoted to motivation and motives of human conduct. He had no medical degree and, of course, could not practice medicine, though he knew about the anatomy of the brain, having studied phys
*23
iologieal psychology and neurology. He had given insanity and diseases of the brain special study. I do- not think it can be said that his ability to detect insanity is inferior to that of a medical man whose experience along such lines is not so intensive.
The determination of the qualifications of an expert is a question for the trial judge and we entrust the matter to his discretion. "We interfere only to correct an abuse.
McEwen
v.
Bigelow,
40 Mich. 215 ;
Ives
v.
Leonard,
50 Mich. 296 ;
People
v.
McQuaid,
85 Mich. 123 ;
People
v.
Kimbrough,
193 Mich. 330 . No case has been called to my attention where a general medical training has been held to be the
sine qua non
of the competency of a trained specialist to advise on the matter of insanity.' In
Evans
v.
People,
12 Mich. 27 , it was held that a nonmedical witness was erroneously permitted to state that there had been no cases of a particular disease in the neighborhood, to rebut opposing medical witnesses who claimed that there was an epidemic of the particular disease. Justice Campbell wrote that “it often happens that some persons having no general skill become very familiar with particular subjects.” “It would be very unwise, ’ ’ he said, “to exclude such evidence merely because the range of the witness’s knowledge is limited. There are as many grades of knowledge and ignorance in the professions as out of them. The only safe rule in any of these cases is, to ascertain the extent of the witness’s qualifications, and within their range, to permit him to speak. ’ ’ The question and its answer were held improper because the witness was not shown to have any knowledge of the disease in question. In
Fox
v.
Peninsular White Lead & Color Works,
92 Mich. 243 ( 16 Am. Neg. Cas. 66 ), it was.held that a witness who was not a physician or graduate of any medical school but who had given “a good deal of attention
*24
to chemistry” and had studied for 15 years the effect of certain chemicals on men working with them could state what his observations had been as to the cutaneous diseases which resulted therefrom. In
People
v.
Rice,
159 N. Y. 400 ( 54 N. E. 48 ), the court said:
“After a careful consideration of the subject we have reached the conclusion that if a man be in reality an expert upon any given subject belonging to the domain of medicine, his opinion may be received by the court, although he has not a license to practice medicine. But such testimony should be received with great caution, and only after the trial court has become fully satisfied that upon the subject as to which the witness is called for the purpose of giving an opinion, he is fully competent to speak. The witness Fenner was not
prima facie
competent, for he had not been licensed to practice medicine. It was essential, therefore, to prove him to be an expert before the defense acquired the right to have him testify as to the sanity or insanity of the defendant.”
The statement might perhaps be challenged as dictum because it was found that the knowledge was in fact inadequate, but I think the expression is sound law. In
Hamilton
v.
United States,
26 App. D. C. 382, the trial judge did not permit a hospital steward at a jail who had attended medical lectures but was not a graduate to testify as an expe'rt on insanity, and his ruling was affirmed on the ground that the determination of competency was for the discretion of the trial court and that he had not abused his authority by excluding the witness. The case does not decide that in all situations a nonmedical without personal observation of the facts is unqualified to advise the court on questions of insanity. When a nonmedical is offered as an expert on sub
*25
jects in the orbit of medical science, the trial court is put on guard and should take greater precaution in the preliminary inquiry to determine the witness’s qualifications and the extent of his knowledge than might be necessary when a graduate of a medical school is proposed. Yet it may well be that for some purposes, as where the issue concerns proper medical treatment, even a licensed physician would not possess sufficient knowledge in a particular branch of his calling to satisfy a trial judge who, within discretionary limits, insists upon a high .standard of reliability. There is no magic in particular titles or degrees and, in our age of intense scientific specialization, we might deny ourselves the use of the best knowledge available by a rule that would immutably fix the educational qualifications to a particular degree.
Nevertheless, I concur in the result reached by Mr. Justice McAllister. If error there was in sustaining the objection to the competency of the witness, its prejudicial effect was removed when the court gave the defense an opportunity to recall the witness to testify as to any observations while in contact with the defendant and any conclusions. The witness had known the defendant as a college student who had taken six of his courses and had been with him on numerous occasions on trips in connection with athletic activities. He could still testify as an expert and state conclusions based on his own observation of the facts relating to the case
(Kelley
v.
Richardson,
69 Mich. 430 ;
People
v.
Ferris,
283 Mich. 699 ;
People
v.
Zabijak,
285 Mich. 164 ), and from a practical point of view his conclusions based on his personal acquaintance coupled with a keen, trained understanding of the human mind might carry greater weight with the jury than might his
*26
conclusions based on a hypothetical question without any personal knowledge of the facts. Defendant did not avail himself of the privilege offered; therefore, the error was at most a technical one, and I cannot say that defendant was denied the benefit of his proofs to any prejudicial extent.
Bushnell, C. J., and Sharpe, North, and Wiest, JJ., concurred with Butzel, J.