(Hawkins, p. 75, section 14): "And not only he who on an assault retreats to the wall, or some such strait, beyond which he can go no further before he kills the other, is judged by the law to act upon unavoidable necessity; but also he who being assaulted in such a manner and in such a place that he cannot go back without manifestly endangering his life, kills the other without retreating at all."
(Section 16); "And an officer who kills one that insults him in the execution of his office, and where a private person that kills one who feloniously assaults him in the highway, may justify the fact without ever giving back at all."
There is no occasion for the magistrate to read the riot act. In the case before you, I suppose you will be satisfied when you come to examine the witnesses and compare it with the rules of the common law, abstracted from all mutiny acts and articles of war, that these soldiers were in such a situation that they could not help themselves. People were coming from Royal Exchange Lane, and other parts of the town, with clubs and cord-wood sticks; the soldiers were planted by the wail of the Customhouse; they could not retreat; they were surrounded on all sides, for there were people behind them as well as before them; there were a number of people in the Royal Exchange Lane; the soldiers were so near to the Customhouse that they could not retreat, unless they had gone into the brick wall of it. I shall show you presently that all the party concerned in this unlawful design were guilty of what any one of them did; if anybody threw a snowball it was the act of the whole party; if any struck with a club or threw a club, and the club had killed anybody, the whole party would have been guilty of murder in the law. Lord Chief-Justice Holt, in Mawgrige's case (Keyling, 128), says:—
"Now, it has been held, that if A of his malice prepense assaults B to kill him, and B draws his sword and attacks A and pursues him, then A, for his safety, gives back and retreats to a wall, and B still pursuing him with his drawn sword, A in his defense kills B; this is murder in A. For A having malice against B, and in pursuance thereof endeavoring to kill him, is answerable for all the consequences of which he was the original cause. It is not reasonable for any man that is dangerously assaulted, and when he perceives his life in danger from his adversary, but to have liberty for the security of his own life, to pursue him that maliciously assaulted him; for he that has manifested that he has malice against another is not at to be trusted with a dangerous weapon in his hand. And so resolved by all the judges when they met at Seargeant's Inn, in preparation for my Lord Morley's trial."
In the case here we will take Montgomery, if you please, when he was attacked by the stout man with a stick, who aimed it at his head, with a number of people round him crying out, "Kill them, kill them." Had he not a right to kill the man? If all the party were guilty of the assault made by the stout man, and all of them had discovered malice in their hearts, had not Montgomery a right, according to Lord Chief-Justice Holt, to put it out of their power to wreak their malice upon him? I will not at present look for any more authorities in the point of self-defense; you will be able to judge from these how far the law goes in justifying or excusing any person in defense of himself, or taking away the life of another who threatens him in life or limb. The next point is this: that in case of an unlawful assembly, all and every one of the assembly is guilty of all and every unlawful act committed by any one of that assembly in prosecution of the unlawful design set out upon.
Rules of law should be universally known, whatever effect they may have on politics; they are rules of common law, the law of the land; and it is certainly true, that wherever there is an unlawful assembly, let it consist of many persons or of a few, every man in it is guilty of every unlawful act committed by any one of the whole party, be they more or be they less, in pursuance of their unlawful design. This is the policy of the law; to discourage and prevent riots, insurrections, turbulence, and tumults.
In the continual vicissitudes of human things, amidst the shocks of fortune and the whirls of passion that take place at certain critical seasons, even in the mildest government, the people are liable to run into riots and tumults. There are Church-quakes and State-quakes in the moral and political world, as well as earthquakes, storms, and tempests in the physical. Thus much, however, must be said in favor of the people and of human nature, that it is a general, if not a universal truth, that the aptitude of the people to mutinies, seditions, tumults, and insurrections, is in direct proportion to the despotism of the government. In governments completely despotic,—that is, where the will of one man is the only law, this disposition is most prevalent. In aristocracies next; in mixed monarchies, less than either of the former; in complete republics the least of all, and under the same form of governments as in a limited monarchy, for example, the virtue and wisdom of the administrations may generally be measured by the peace and order that are seen among the people. However this may be, such is the imperfection of all things in this world, that no form of government, and perhaps no virtue or wisdom in the administration, can at all times avoid riots and disorders among the people.
Now, it is from this difficulty that the policy of the law has framed such strong discouragements to secure the people against tumults; because, when they once begin, there is danger of their running to such excesses as will overturn the whole system of government. There is the rule from the reverend sage of the law, so often quoted before:—
(1 H. H. P. C. 437): "All present, aiding and assisting, are equally principal with him that gave the stroke whereof the party died. For though one gave the stroke, yet in interpretation of law it is the stroke of every person that was present, aiding and assisting."
(1 H. H. P. C. 440): "If divers come with one assent to do mischief, as to kill, to rob or beat, and one doeth it, they are all principals in the felony. If many be present and one only give the stroke whereof the party dies, they are all principal, if they came for that purpose."