While considerable latitude is permitted in the reception of opinion evidence as to mental capacity from witnesses who base their opinions upon personal association, transactions and conversations (In re Rawlings’ Will, 170 N. C., 58, 86 S. E., 794), this rule should not be expanded to include mere expressions of opinion not based on circumstances importing mental incapacity, nor should the witnesses be permitted to answer questions as to whether the person whose mental capacity is the subject of inquiry had sufficient mental capacity to make a will or execute a deed, when neither by the question nor by instructions of court or counsel have the witnesses been apprised of what is in law meant by, or required to constitute, mental capacity sufficient to make" a will.
,To ask a witness whether in his opinion the person under investigation was or was not competent to make a will is improper for the reason that such question assumes the witness knows, or leaves to him to determine for himself, what is or should be the proper test of mental capacity to execute a valid will. Rogers Expert Testimony, 3rd Ed., sec. 206. The obvious objections to allowing a witness to answer the general question as to whether or not a person was capable of making a will or *462contract have led tbe courts generally to exclude tbe conclusions of witnesses in answer to sucb questions.
“By all courts a mere abstract statement tbat tbe person was or was not ‘capable’ of making a will or a contract or a deed seems to be beld improper; but there is a great contrariety of ruling upon Other fcTrms of statement.” Wigmore Ev., sec. 1958. Capacity to make a will is not a simple question of fact. It is a conclusion which the law draws from certain facts as premises. Lawson Expert & Opinion Ev., page 155. Hence, the witness must state the facts gained from personal obsefvation as a predicate for the expression of his opinion. Turner v. Am. Security & Tr. Co., 213 U. S., 257; Smoot Law of Insanity, sec. 599.
Failure to observe this rule, in the admissions of the evidence elicited by the questions objected to in the- case at bar, has, we think, prejudiced the propounder’s cause. Several non-expert witnesses were permitted to say the decedent at the time of executing the paper writing propounded did not have mental capacity to make a will, apparently without understanding what degree of mental capacity was necessary to constitute legal competency.
While the court in his charge to the jury properly defined mental capacity in accordance with the decisions of this Court (Carland v. Allison, 221 N. C., 120, 19 S. E. (2d), 245; In re Broach’s Will, 172 N. C., 520, 90 S. E., 681; In re Thorp, 150 N. C., 487, 64 S. E., 379), we think there was prejudicial error in the admission of testimony, necessitating a new trial, and it is so ordered.