200 HARVARD LAW REVIEW. to establish his position by evidence that would appeal, not to his mind, but to the mind of some one else. What would have become of his decision in that case? Could he have fully explained, even to himself, much less to anybody else, precisely why he thought as he did? He was a personal friend of a gentleman on the other side, and they had studied the uses of artillery together before the war. Could he have explained, even to himself, the precise extent to which the result of this intimacy influenced his decision, or of half a dozen other similar considerations? And yet no one doubts that the value of a decision in any other profession except the law lies in just such considerations as these, — considerations that a lawyer necessarily disregards. Evidence that appeals to his mind alone is for him useless. His work deals with what is transferable, — with what he can explain and teach to some one else. His highest title is Learned. The rest of the work, the part where sagacity and insight are required, he turns over to the jury. And the line between the functions of the court and those of the jury follows very closely the line dividing matter decided by learning* from matter decided by sagacity. It is often said that the court decides matters of law; but the court also decides all those ques- tions of fact which require uniformity, that is, all those matters where a decision in one case can be readily made by following a decision in a previous case.^ On the other hand, where there is no opportunity for precedent or learning, the questions are left to the jury, — questions of law as well as of fact. In a suit for negli- gence every single thing that every person, in any way connected with the accident, did, may be known and undisputed, and the case may be reduced to a question of conduct, pure and simple. But if the accident occurred in the management of some new machine or some new enterprise, or when the circumstances are so com- plicated as to present a new situation, " even if the facts are undis- puted, the question whether either or both of the parties were at fault is for the jury."^ 1 Prof. J. B. Thayer, Law and Fact in Jury Trials, Harvard Law Review, iv. 1 59-161. 2 Kerrigan v. West End vSt. Ry. Co., 158 Mass. 305. How far the repugnance to new facts is characteristic of lawyers learned in systems other than the common law may perhaps be doubted. The reader will at once recall Lord Mansfield's delicate scorn when he observed that the Roman tribunals at once, and the English at last, decided according to the undisputed intent of the testator, which was manifest on the face of the will, and yet not categorically set down in words. Op. in Frogmorton v. Holliday, 3 Burr. 1618, 1624.