Now, if experience shows, or is deemed by the law-maker to show, that somehow or other deaths which the evidence makes accidental happen disproportionately often in connection with other felonies, or with resistance to officers, or if on any other ground of policy it is deemed desirable to make special efforts for the prevention of such deaths, the lawmaker may consistently treat acts which, under the known circumstances, are felonious, or constitute resistance to officers, as having a sufficiently dangerous tendency to be put under a special ban.  The law may, therefore, throw on the actor the peril, not only of the consequences foreseen by him, but also of consequences which, although not predicted by common experience, the legislator apprehends.  I do not, however, mean to argue that the rules under discussion arose on the above reasoning, any more than that they are right, or would be generally applied in this country.

Returning to the main line of thought it will be instructive to consider the relation of manslaughter to murder.  One great difference between the two will be found to lie in the degree of danger attaching to the act in the given state of facts.  If a man strikes another with a small stick which is not likely to kill, and which he has no reason to suppose will do more than slight bodily harm, but which [60] does kill the other, he commits manslaughter, not murder. 1 But if the blow is struck as hard as possible with an iron bar an inch thick, it is murder. 2 So if, at the time of striking with a switch, the party knows an additional fact, by reason of which he foresees that death will be the consequence of a slight blow, as, for instance, that the other has heart disease, the offence is equally murder. 3 To explode a barrel of gunpowder in a crowded street, and kill people, is murder, although the actor hopes that no such harm will be done. 4 But to kill a man by careless riding in the same street would commonly be manslaughter. 5 Perhaps, however, a case could be put where the riding was so manifestly dangerous that it would be murder.

To recur to an example which has been used already for another purpose:  “When a workman flings down a stone or piece of timber into the street, and kills a man; this may be either misadventure, manslaughter, or murder, according to the circumstances under which the original act was done:  if it were in a country village, where few passengers are, and he calls out to all people to have a care, it is misadventure only; but if it were in London, or other populous town, where people are continually passing, it is manslaughter, though he gives loud warning; and murder, if he knows of their passing, and gives no warning at all.” 6

The law of manslaughter contains another doctrine [61] which should be referred to in order to complete the understanding of the general principles of the criminal law.  This doctrine is, that provocation may reduce an offence which would otherwise have been murder to manslaughter.  According to current morality, a man is not so much to blame for an act done under the disturbance of great excitement, caused by a wrong done to himself, as when he is calm.  The law is made to govern men through their motives, and it must, therefore, take their mental constitution into account.