Unlike mistake, inevitable accident is commonly recognised by our law as a ground of exemption from liability. It is needful, therefore, to distinguish accurately between these two things, for they are near of kin. Every act which is not done intentionally is done either accidentally or by mistake. It is done accidentally, when it is unintentional in respect of its consequences. It is done by mistake, when it is intentional in respect of its consequences, but unintentional in respect of some material circumstance. If I drive over a man in the dark because I do not know that he is in the road, I injure him accidentally; but if I procure his arrest, because I mistake him for some one who is liable to arrest, I injure him not accidentally but by mistake. In the former case I did not intend the harm at all, while in the latter case I fully intended it, but falsely believed in the existence of a circumstance which would have served to justify it. So if by insufficient care I allow my cattle to escape into my neighbour’s field, their presence there is due to accident; but if I put them there because I wrongly believe that the field is mine, their presence is due to mistake. In neither case did I intend to wrong my neighbour, but in the one case my intention failed as to the consequence, and in the other as to the circumstance.
Accident, like mistake, is either culpable or inevitable. It is culpable when due to negligence, but inevitable when the avoidance of it would have required a degree of care exceeding the standard demanded by the law. Culpable accident is no defence, save in those exceptional cases in which wrongful intent is the exclusive and necessary ground of liability. Inevitable accident is commonly a good defence, both in the civil and in the criminal law.
To this rule, however, there are, at least in the civil law, important exceptions. These are cases in which the law insists that a man shall act at his peril, and shall take his chance of accidents happening. If he desires to keep wild beasts,[[387]] or to light fires,[[388]] or to construct a reservoir of water,[[389]] or to accumulate upon his land any substance which will do damage to his neighbours if it escapes,[[390]] or to erect dangerous structures by which passengers in the highway may come to harm,[[390]] he will do all these things suo periculo (though none of them are per se wrongful) and will answer for all ensuing damage notwithstanding consummate care.
There is one case of absolute liability for accident which deserves special notice by reason of its historical origin. Every man is absolutely responsible for the trespasses of his cattle. If my horse or my ox escapes from my land to that of another man, I am answerable for it without any proof of negligence.[[391]] Such a rule may probably be justified as based on a reasonable presumption of law that all such trespasses are the outcome of negligent keeping. Viewed historically, however, the rule is worth notice as one of the last relics of the ancient principle that a man is answerable for all damage done by his property. In the theory of ancient law I am liable for the trespasses of my cattle, not because of my negligent keeping of them, but because of my ownership of them. For the same reason in Roman law a master was liable for the offences of his slaves. The case is really, in its historical origin, one of vicarious liability. In early law and custom vengeance, and its products responsibility and punishment, were not conceived as necessarily limited to human beings, but were in certain cases extended to dumb animals and even inanimate objects. We have already cited in another connection the provision of the Mosaic law that “If an ox gore a man or a woman that they die, then the ox shall be surely stoned and his flesh shall not be eaten.”[[392]] In the Laws of Plato it is said:[[393]] “If a beast of burden or other animal cause the death of any one ... the kinsman of the deceased shall prosecute the slayer for murder, and the wardens of the country ... shall try the cause; and let the beast when condemned be slain by them, and cast beyond the borders.” So in the Laws of King Alfred:[[394]] “If at their common work,” (of wood cutting) “one man slay another unwilfully, let the tree be given to the kindred.” And by English law until the year 1846 the weapon or other thing which “moved to the death of a man” was forfeited to the King as guilty and accursed.[[395]] Here we have the ground of a rule of absolute liability. If a man’s cattle or his slaves do damage, they are thereby exposed to the vengeance of the injured person. But to take destructive vengeance upon them is to impose a penalty upon their owner. The liability thence resulting probably passed through three stages: first, that of unconditional forfeiture or surrender of the property to the vengeance of the injured person; secondly, that of an option given to the owner between forfeiture and redemption—the actiones noxales of Roman law;[[396]] and thirdly, that of compulsory redemption, or in other words, unconditional compensation.
§ 149. Vicarious Responsibility.
Hitherto we have dealt exclusively with the conditions of liability, and it is needful now to consider its incidence. Normally and naturally the person who is liable for a wrong is he who does it. Yet both ancient and modern law admit instances of vicarious liability in which one man is made answerable for the acts of another. Criminal responsibility, indeed, is never vicarious at the present day, except in very special circumstances and in certain of its less serious forms.[[397]] In more primitive systems, however, the impulse to extend vicariously the incidence of liability receives free scope in a manner altogether alien to modern notions of justice. It is in barbarous times considered a very natural thing to make every man answerable for those who are of kin to him. In the Mosaic legislation it is deemed necessary to lay down the express rule that “The fathers shall not be put to death for the children; neither shall the children be put to death for the fathers; every man shall be put to death for his own sin.”[[398]] Plato in his Laws does not deem it needless to emphasise the same principle.[[399]] Furthermore, so long as punishment is conceived rather as expiative, retributive, and vindictive, than as deterrent and reformative, there seems no reason why the incidence of liability should not be determined by consent, and therefore why a guilty man should not provide a substitute to bear his penalty and to provide the needful satisfaction to the law. Guilt must be wiped out by punishment, but there is no reason why the victim should be one person rather than another. Such modes of thought have long since ceased to pervert the law; but that they were at one time natural is rendered sufficiently evident by their survival in popular theology.
Modern civil law recognises vicarious liability in two chief classes of cases. In the first place, masters are responsible for the acts of their servants done in the course of their employment. In the second place, representatives of dead men are liable for deeds done in the flesh by those whom they represent. We shall briefly consider each of these two forms.
It has been sometimes said that the responsibility of a master for his servant has its historical source in the responsibility of an owner for his slave. This, however, is certainly not the case. The English doctrine of employer’s liability is of comparatively recent growth. It has its origin in the legal presumption, gradually become conclusive, that all acts done by a servant in and about his master’s business are done by his master’s express or implied authority, and are therefore in truth the acts of the master for which he may be justly held responsible.[[400]] No employer will be allowed to say that he did not authorise the act complained of, or even that it was done against his express injunctions, for he is liable none the less. This conclusive presumption of authority has now, after the manner of such presumptions, disappeared from the law, after having permanently modified it by establishing the principle of employer’s liability. Historically, as we have said, this is a fictitious extension of the principle, Qui facit per alium facit per se. Formally, it has been reduced to the laconic maxim, Respondeat superior.
The rational basis of this form of vicarious liability is in the first place evidential. There are such immense difficulties in the way of proving actual authority, that it is necessary to establish a conclusive presumption of it. A word, a gesture, or a tone may be a sufficient indication from a master to his servant that some lapse from the legal standard of care or honesty will be deemed acceptable service. Yet who could prove such a measure of complicity? Who could establish liability in such a case, were evidence of authority required, or evidence of the want of it admitted?
A further reason for the vicarious responsibility of employers is that employers usually are, while their servants usually are not, financially capable of the burden of civil liability. It is felt, probably with justice, that a man who is able to make compensation for the hurtful results of his activities should not be enabled to escape from the duty of doing so by delegating the exercise of these activities to servants or agents from whom no redress can be obtained. Such delegation confers upon impecunious persons means and opportunities of mischief which would otherwise be confined to those who are financially competent. It disturbs the correspondence which would otherwise exist between the capacity of doing harm and the capacity of paying for it. It is requisite for the efficacy of civil justice that this delegation of powers and functions should be permitted only on the condition that he who delegates them shall remain answerable for the acts of his servants, as he would be for his own.