Pepper, 1 which decided that there was no battery when a man’s horse was frightened by accident or a third person and ran away with him, and ran over the plaintiff, takes the distinction that, if the rider by spurring is the cause of [92] the accident, then he is guilty.  In Scott v.  Shepherd, 1 already mentioned, trespass was maintained against one who had thrown a squib into a crowd, where it was tossed from hand to hand in self-defence until it burst and injured the plaintiff.  Here even human agencies were a part of the chain between the defendant’s act and the result, although they were treated as more or less nearly automatic, in order to arrive at the decision.

Now I repeat, that, if principle requires us to charge a man in trespass when his act has brought force to bear on another through a comparatively short train of intervening causes, in spite of his having used all possible care, it requires the same liability, however numerous and unexpected the events between the act and the result.  If running a man down is a trespass when the accident can be referred to the rider’s act of spurring, why is it not a tort in every case, as was argued in Vincent v.  Stinehour, 2 seeing that it can always be referred more remotely to his act of mounting and taking the horse out?

Why is a man not responsible for the consequences of an act innocent in its direct and obvious effects, when those consequences would not have followed but for the intervention of a series of extraordinary, although natural, events?  The reason is, that, if the intervening events are of such a kind that no foresight could have been expected to look out for them, the defendant is not to blame for having failed to do so.  It seems to be admitted by the English judges that, even on the question whether the acts of leaving dry trimmings in hot weather by the side of a railroad, and then sending an engine over the track, are [93] negligent,—­that is, are a ground of liability,—­the consequences which might reasonably be anticipated are material. 1 Yet these are acts which, under the circumstances, can hardly be called innocent in their natural and obvious effects.  The same doctrine has been applied to acts in violation of statute which could not reasonably have been expected to lead to the result complained of. 2

But there is no difference in principle between the case where a natural cause or physical factor intervenes after the act in some way not to be foreseen, and turns what seemed innocent to harm, and the case where such a cause or factor intervenes, unknown, at the time; as, for the matter of that, it did in the English cases cited.  If a man is excused in the one case because he is not to blame, he must be in the other.  The difference taken in Gibbons v.  Pepper, cited above, is not between results which are and those which are not the consequences of the defendant’s acts:  it is between consequences which he was