I concur in the foregoing conclusions of the chief-justice, and for the reasons given by him. The principal question in this case has been much discussed in the English and American courts, though but little in this state. The rule, that the plaintiff can recover only when the defendant's act or negligence was the proximate cause of the injury, is one of universal application; but the difficulty lies in determining when the cause is proximate and when remote. It is a mixed question of law and of fact, to be submitted to the jury under proper instructions. We have recently held that it is always for the jury to say whether the damage sustained is what the defendant ought to have expected, in the exercise of reasonable care and discretion. Stark v. Lancaster, ante 88, and authorities cited; McIntyre v. Plaisted, ante 606; — see, also, State v. M. L. R. R., 52 N.H. 552; Cate v. Cate, 50 N.H. 144; Underhill v. Manchester, 45 N.H. 218.
The rule, as thus laid down, is also given in substance in 2 Parsons on Contracts 456, 2 Gr. Ev., sec. 256, and Sedgwick on Damages 88. The numerous cases in which this question has been discussed are cited by the above authors. It would be an unnecessary labor to review them in detail.
In this case the evidence tended to show the intervention of a new cause of the destruction of the plaintiff's sheep after their escape from his pasture, which could not reasonably have been anticipated. The only practicable rule to be drawn from all the cases, for determining this case, it seems to me, is, to inquire whether the loss of the plaintiff's sheep by boars was an event which might reasonably have been anticipated from the defendant's act in leaving his bars down, under all the circumstances of this case. If it was a natural consequence which any reasonable person could have anticipated, then the defendant's act was the proximate cause. If, on the other hand, the bears were a new agency, which could not reasonably have been anticipated, the loss of the sheep must be set down as a remote consequence, for which the defendant is not responsible.
The jury were instructed that if the sheep escaped in consequence of the bars being left down by the defendant, and would not have been killed but for this act of the defendant, he was liable. Under these *Page 631 instructions the jury could not inquire whether the destruction of the sheep by the bears was an event which might reasonably have been anticipated from the leaving of the bars down, and for this reason I agree that the verdict must be set aside.