OPINION. In Evidence. An inference or conclusion drawn by a witness as distin guished from facts known to him as facts.
It is the province of the jury to draw in ferences and conclusions; and if witnesses were in general allowed to testify what they believe as well as what they know, the ver dict would sometimes prove not the decision of the jury, but that of the witnesses. Hence the rule that, in general, the witness cannot be asked his opinion upon a particular ques tion ; Patterson v. Colebrook, 29 N. H. 94; Dawson v. Callaway, 18 Ga. 573 ; Morehouse v. Mathews, 2 N. Y. 514; De Witt v. Barly, 17 N. Y. 340.
Where all the facts of a transaction are clearly stated by a witness, his inference therefrom is inadmissible ; Gentry v. Single ton, 128 Fed. 679, 63 C. C. A. 231.
While it is incompetent for a witness to state his opinion upon a question of law, where the intent with which an act done by him is drawn in question he may testify as to such intent ; 12 Reptr. 664.
Some confusion in the application of this rule arises from the delicacy of the line which divides that which is to be regarded as matter of observation from that which is matter of judgment founded upon ob servation. Thus, it is held that an unpro fessional witness may testify to the fact that a person whom he saw was intoxicated, whether he is able to state all the constit uent facts which amount to drunkenness or hot; People v. Eastwood, 14 N. Y. 562; Stan ley v. State, 26 Ala. 26; McKillop v. Ry. Co., 53 Minn. 532, 55 N. W. 739; he may also tes tify as to the apparent condition of a party as to sobriety, shortly before the commission of an offence ; People v. Monteith, 73 Cal. 7, 14 Pac. 373. He is also competent to testify whether a person with whom he is familiarly associated is in good or bad health and hear ing, is lame or has the natural use of his limbs, and also whether on certain occasions he was unconscious ; Chicago City Ry. Co. v. Van Vleck, 143 Ill. 480, 32 N. E. 262; also whether a certain person has African blood in his veins ; Hare v. Board of Education, 113 N. C. 9, 18 S. E. 55. But, on the oth,er hand, insanity or mental incapacity cannot, in general, be proved by the mere assertion of an unprofessional witness; De Witt v.
Barly, 17 N. Y. 340; Gehrke v. State, 13 Tex. 568; but the opinion of non-expert wit nesses may be given as to mental capacity where the facts upon which the opinions are based are disclosed ; Johnson v. Culver, 116 Ind. 278, 19 N. E. 129; Keithley v. Staf ford, 126 III. 507, 18 N. D. 740 ; State v. Potts, 100 N. C. 457, 6 S. E. 657; Frizzell v. Reed, 77 Ga. 724; Fishburne v. Ferguson's Heirs, 84 Va. 87, 4 S. E. 575.
So handwriting may be proved by being recognized by a witness who has seen other writings of the party in the usual course of business, or who has seen him write; Steph. Ey. § 51; Titford v. Knott, 2 Johns. Cas. (N. Y.) 211 ; Snider v. Burks, 84 Ala. 53, 4 South. 225. See Brown v. Hall, 85 Va. 146, 7 S. E. 182. But, on the other hand, the au thorship of an anonymous article in a news paper cannot be proved by one professing to have a knowledge of the author's style; Lee v. Bennett, How. App. Cas. 187.
The mere opinions of witnesses, without the facts on which they are based, are of very little value, especially where the wit nesses are constitutionally or by interest biased and not impartial; Pannell v. Tobac co Warehouse Co., 113 Ky. 630, 68 S. W. 662, 82 S. W. 1141; Kerr v. Lunsford, 31 W. Va. 659, 8 S. E. 493, 2 L. R. A. 668.
From necessity, an exception to the rule of excluding opinions is made in questions involving matters of science, art, or trade, where skill and knowledge possessed by a witness, peculiar to the subject, give a value to his opinion above that of any inference' which the jury could draw from facts which he might state ; People v. Bodine, 1 Denio (N. Y.) 281; Reed v. Hobbs, 2 Scam. (III.) 297; Woodman v. Barker, 2 N. H. 480; Al fonso v. U. S., 2 Story 421, Fed. Cas. No. 188. Such a witness is termed an expert; and he may give hls opinion in evidence; Whart. Ev. 440. Experts alone can give an opinion based on facts shown by others, assuming them to be true; State v. Potts, 100 N. C. 457, 6 S. E. 657.