In the first place, it is said, consider generally the protection given by the law to property, both within and outside the limits of the last-named action.  If a man crosses his neighbor’s boundary by however innocent a mistake, or if his cattle escape into his neighbor’s field, he is said to be liable in trespass quare clausum fregit.  If an auctioneer in the most perfect good faith, and in the regular course of his business, sells goods sent to his rooms for the purpose of being sold, he may be compelled to pay their full value if a third person turns out to be the owner, although he has paid over the proceeds, and has no means of obtaining indemnity.

Now suppose that, instead of a dealing with the plaintiff’s property, the case is that force has proceeded directly from the defendant’s body to the plaintiff’s body, it is urged that, as the law cannot be less careful of the persons than of the property of its subjects, the only defences possible are similar to those which would have been open to an alleged trespass on land.  You may show that there was no trespass by showing that the defendant did no act; as where he was thrown from his horse upon the plaintiff, or where a third person took his hand and struck the plaintiff with it.  In such cases the defendant’s body is file passive instrument of an external force, and the bodily motion relied on by the plaintiff is not his act at all.  So you may show a justification or excuse in the conduct of the plaintiff himself.  But if no such excuse is shown, and the defendant has voluntarily acted, he must answer [84] for the consequences, however little intended and however unforeseen.  If, for instance, being assaulted by a third person, the defendant lifted his stick and accidentally hit the plaintiff, who was standing behind him, according to this view he is liable, irrespective of any negligence toward the party injured.

The arguments for the doctrine under consideration are, for the most part, drawn from precedent, but it is sometimes supposed to be defensible as theoretically sound.  Every man, it is said, has an absolute right to his person, and so forth, free from detriment at the hands of his neighbors.  In the cases put, the plaintiff has done nothing; the defendant, on the other hand, has chosen to act.  As between the two, the party whose voluntary conduct has caused the damage should suffer, rather than one who has had no share in producing it.

We have more difficult matter to deal with when we turn to the pleadings and precedents in trespass.  The declaration says nothing of negligence, and it is clear that the damage need not have been intended.  The words vi et armis and contra pacere, which might seem to imply intent, are supposed to have been inserted merely to give jurisdiction to the king’s court.  Glanvill says it belongs to the sheriff, in case of neglect on the part of lords of franchise, to take cognizance of melees, blows, and even wounds, unless