So, in the case of a barrel falling from a warehouse window, it must be found that the defendant or his servants were in charge of it, before any question of standard can arise. 2 It will be seen that in each of these well-known cases the court assumed a rule which would make the defendant liable if his conduct was such as the evidence tended to prove.  When there is no question as to the conduct established by the evidence, as in the case of a collision between two trains belonging to the same company, the jury have, sometimes at least, been told in effect that, if they believed the evidence, the defendant was liable. 3

The principal argument that is urged in favor of the view that a more extended function belongs to the jury as matter of right, is the necessity of continually conforming our standards to experience.  No doubt the general foundation of legal liability in blameworthiness, as determined by the existing average standards of the community, should always be kept in mind, for the purpose of keeping such concrete rules as from time to time may be laid down conformable to daily life.  No doubt this conformity is the practical justification for requiring a man to know the civil law, as the fact that crimes are also generally sins is one of the practical justifications for requiring a man to know the criminal law.  But these considerations only lead to [126] the conclusion that precedents should be overruled when they become inconsistent with present conditions; and this has generally happened, except with regard to the construction of deeds and wills.  On the other hand, it is very desirable to know as nearly as we can the standard by which we shall be judged at a given moment, and, moreover, the standards for a very large part of human conduct do not vary from century to century.

The considerations urged in this Lecture are of peculiar importance in this country, or at least in States where the law is as it stands in Massachusetts.  In England, the judges at nisi prius express their opinions freely on the value and weight of the evidence, and the judges in banc, by consent of parties, constantly draw inferences of fact.  Hence nice distinctions as to the province of court and jury are not of the first necessity.  But when judges are forbidden by statute to charge the jury with respect to matters of fact, and when the court in banc will never hear a case calling for inferences of fact, it becomes of vital importance to understand that, when standards of conduct are left to the jury, it is a temporary surrender of a judicial function which may be resumed at any moment in any case when the court feels competent to do so.  Were this not so, the almost universal acceptance of the first proposition in this Lecture, that the general foundation of liability for unintentional wrongs is conduct different from that of a prudent man under the circumstances, would leave all our rights and duties throughout a great part of the law to the necessarily more or less accidental feelings of a jury.