Roman law and English law begin with a set of what might be called nominate delicts or nominate torts. In Roman law there were furtum (conversion), rapina (forcible conversion) and iniuria (wilful aggression upon personality). All these involved dolus, i.e. intentional aggression. The lex Aquilia added damnum iniuria datum (wrongful injury to property). Later there were added what might be called the equitable delicts of dolus (fraud) and metus (duress). Here also there was wilful aggression, and the delict of dolus gets its name from the intentional misleading that characterizes it in Roman law as it does deceit in English law. In damnum iniuria datum, a wider conception of fault, as distinguished from intentional aggression, grew up by juristic development, and Aquilian culpa, that is, a fault causing injury to property and therefore actionable on the analogy of the lex Aquilia, furnished the model for the modern law. All these may be fitted to the will theory and modern systematic writers regularly do so. But noxal liability for injury done by a child or slave or domestic animal did not fit it, nor did the liability of a master of a ship, an innkeeper or a stable keeper to respond without regard to fault. Liability for injury done by child or slave or domestic animal was enforced in a noxal action on the analogy of the action which lay for the same injury if done by the defendant in person. Hence procedurally it seemed liability for a delict involving intentional aggression, and it was possible to say that there was fault in not restraining the agency that did the injury, although no fault had to be shown nor could absence of fault be shown as a defence. There was fault because there was liability, for all liability grew out of fault. Such treadings on the tail of its own argument are very common in legal reasoning. Likewise in the case of the absolute liability of the master of a ship, the innkeeper and the stable keeper, the institutional writers could say that they were at fault in not having proper servants, although here also fault need not be established by proof nor could want of fault be made a defence. As procedurally these liabilities arose in actions on the facts of particular cases, the jurists at first lumped them with many other forms of liability, which were not in fact dependent on intention and were enforced in actions in factum, as obligations arising from the special facts of cases (obligationes ex uariis causarum figuris). Later they were called quasi-delictual obligations and they are so designated in the fourfold classification of the Institutes. Buckland has remarked that in almost all of the liabilities included under quasi-delict in the Institutes there is liability at one's peril for the act of another, especially for one's servant, as in the noxal actions, the actio de deiectis et diffusis (for things thrown or poured from buildings upon a way) and the actio de recepto against an innkeeper. In other words, in these cases one was held without regard to fault for injuries incidental to the conduct of certain enterprises or callings and for failure to restrain potentially injurious agencies which one maintained.
Modern law has given up both the nominate delicts and quasi-delict, as things of any significance. The French civil code made the idea of Aquilian culpa into a general theory of delictal liability, saying, "Every act of man which causes damage to another obliges him through whose fault it happened to make reparation." In other words, liability is to be based on an act, and it must be a culpable act. Act, culpability, causation, damage, were the elements. This simple theory of liability for culpable causation of damage was accepted universally by civilians until late in the nineteenth century and is still orthodox. Taken up by text writers on torts in the last half of that century, it had much influence in Anglo-American law. But along with this generalization the French code preserved a liability without fault, developed out of the noxal actions, whereby parents and teachers may be held for injuries by minors under their charge, masters for injuries by their apprentices, employers for injuries by employees and those in charge of animals for injuries by such animals. Also it provided an absolute liability for injury by a res ruinosa, developed out of the Roman cautio damni infecti. In the case of parents, teachers and masters of apprentices, there is only a presumption of fault. They may escape by showing affirmatively that they were without fault and that what happened could not have been prevented by diligence on their part. In the case of employers no excuse is admitted. The liability is absolute. In the case of animals, fault of the victim, inevitable accident and vis maior may be shown affirmatively by way of defence. In the case of a res ruinosa there is no presumption of fault. But if the structure fell or did injury because of a defect of construction or want of repair, the owner is liable absolutely and may not show that he had no notice of the defect and no reason to suspect it, or that it was not in his power to prevent the structure from falling.
Thus it will be seen that French law came very near to a logically consistent scheme of liability for fault, and civil liability for fault only, throughout the whole delictal field. Employer's liability remained absolute, and liability for animals but little short of absolute. For the rest there was in certain cases an imposition of the burden of proof that there had been no fault, leaving the ultimate liability to rest upon a presumed fault, if want of fault was not established. None the less this, the most thoroughgoing attempt to make delictal liability flow exclusively from culpability—to make it a corollary of fault and of fault only—fell short of complete attainment of its aim. Recent French authors do not hesitate to say that the attempt must be given over and that a new theory of civil delictal liability must be worked out. Meanwhile the same movement away from the simple theory of delictal liability for culpable causation of damage had taken place elsewhere on the Continent. Binding had subjected the culpa-prinzip to thorough analysis, and following him it had come to be rejected generally by recent German and Swiss jurists.
In the common law, as has been said, we begin likewise with a set of nominate torts—assault, battery, imprisonment, trespass on lands, trespass on chattels, conversion, deceit, malicious prosecution, slander and libel—developed procedurally through the action of trespass and the action of trespass on the case. All of these, except trespass on lands, trespass upon possession of chattels and conversion, are cases of intentional injury. Trespass on lands, trespass on chattels and conversion involve more than the general security and must be considered in connection with ideas of property. The social interest in security of acquisitions demands that we be able to rely on others keeping off of our lands and not molesting our chattels; that they find out for themselves and at their own risk where they are or with whose chattels they are meddling. But even here there must be an act. If there is no act, there is no liability. To these nominate torts, each with its own special rules, coming down from the strict law, we added a new ground of liability, namely, negligence, going on a principle, not of duty to answer for aggression, but of duty to answer for injuries resulting from falling short of a legal standard of conduct governing affirmative courses of action. Some, indeed, sought to give us a "tort of negligence" as a nominate tort. But it was soon recognized that in negligence we have a principle of liability dependent upon a standard, not a tort to be ranged alongside of assault or imprisonment. Later, with the rise of doctrines as to injury to advantageous relations and the failure of negligence to account for all unintended harms of which the law actually was taking note, we developed an indefinite number of innominate torts. Today with the obsolescence of procedural difficulties, there is no reason why we should not generalize, as the civil law did at the beginning of the last century; and such a generalization was attempted in the last third of the nineteenth century. It became orthodox common law that liability was a corollary of fault. So far as established common-law rules imposed a liability without fault, they were said to be historical exceptions, and some of our courts, under the influence of this theory, were willing to go a long way in abrogating them. Liability, without regard to fault, for the acts of servants and employees was reconciled with this theory by the fiction of representation, exposed long ago by Mr. Justice Holmes and later by Dr. Baty. Finally it came to be thought that no liability without fault was not merely common law but was natural law and that any legislative imposition of such liability was arbitrary and unreasonable in itself and hence unconstitutional. On that theory, the New York Court of Appeals held workmen's compensation unconstitutional, and a minority of the Supreme Court of the United States recently announced the same proposition.
Because of its implications for constitutional law, in view of the increasing frequency of legislation imposing responsibility at one's peril in certain enterprises, in the case of certain dangerous agencies and in situations where it is felt that the loss should be borne by all of us rather than by the luckless individual who chances to be hurt, the basis of tort liability has become a question of moment beyond the immediate law of torts. It is a practical question of the first importance, as well as a theoretical question of interest, whether we are to generalize our whole system of tort liability by means of one principle of liability for fault and for fault only, as the French sought to do and as we later sought to do largely under their influence, or, on the other hand, are to admit another source of delictal liability alongside of fault, as the French law does in fact and is coming to do in theory, and as our law has always done in fact. For in our law as it stands one may perceive readily three types of delictual liability: (1) Liability for intentional harm, (2) liability for unintentional culpable harm, (3) liability in certain cases for unintended non-culpable harm. The first two comport with the doctrine of no liability without fault. The third cannot be fitted thereto. We must either brand cases of the third type as historical anomalies, of which we are gradually to rid ourselves, or else revise our notions of tort liability. Let us remember that the nineteenth century was well advanced before we understood the subject of negligence and that before we had convinced ourselves that no liability without fault was orthodox common law, the highest court of England had given absolute liability a new field by the decision in Rylands v. Fletcher. We are not questioning a long-established dogma in Anglo-American administration of justice, therefore, when we ask whether the orthodox theory of the last generation is adequate as an analytical statement of the law that is, or as a philosophical theory of the law that ought to be. My own belief is that it is neither.
Suppose that instead of beginning with the individual free will we begin with the wants or claims involved in civilized society—as it has been put, with the jural postulates of civilized society. One such postulate, I think we should agree, is that in civilized society men must be able to assume that others will do them no intended injury—that others will commit no intentional aggressions upon them. The savage must move stealthily, avoid the sky-line and go armed. The civilized man assumes that no one will attack him and so moves among his fellow men openly and unarmed, going about his business in a minute division of labor. Otherwise there could be no division of labor beyond the differentiation of men of fighting age, as we see it in a primitive society. This postulate is at the foundation of civilized society. Everywhere dolus is first dealt with. The system of nominate delicts or nominate torts, both in Roman law and in our law, proceeds on this postulate.
Is it not another such postulate that in civilized society men must be able to assume that their fellow men, when they act affirmatively, will do so with due care, that is with the care which the ordinary understanding and moral sense of the community exacts, with respect to consequences that may reasonably be anticipated? Such a postulate is the basis of delictal culpa, using culpa in the narrower sense, and of our doctrine of negligence. In Roman law and at one time in our law attempts were made to develop this postulate contractually. If in a transaction involving good faith—that is an informal legal transaction—one's conduct fell short of action to which the other party was justified by the understanding of upright men in expecting him to adhere, there was contractual culpa; there was a violation of a promise implied in the transaction and consequent liability. We borrowed something of this mode of thought from the Romans in our law of bailments and hence think indifferently in terms of tort or contract in that connection, although historically our action for such cases is delictal. In other connections also our law for a time sought to develop this postulate contractually by means of an "implied undertaking to use skill" for which one must answer if his skill fell short of that which the legal standard of affirmative conduct called for under the circumstances. Also in the Year Books an undertaking implied in certain relations or callings to use the skill or diligence which the relation or calling demanded is often made the basis of liability. But here the basis of liability must be found in a relation. The fiction of an undertaking to use the skill or diligence involved in a relation or calling is a juristic way of saying that one who deals with another in such a relation or with another who professes such a calling is justified in assuming the skill and diligence ordinarily involved therein, so that the law holds those in the relation or engaged in the calling to that standard in order to maintain the general security. In other words another, though closely related, postulate of civilized society is involved.
It is worth a moment's digression to suggest that such things show how little the historical categories of delict and contract represent any essential or inherent need of legal thinking. Austin thought that "the distinction of obligations (or of duties corresponding to rights against persons specifically determined) into obligations which arise from contracts, obligations which arise from injuries, and obligations which arise from incidents which are neither contracts nor injuries," was a "necessary distinction," without which a "system of law evolved in a refined community" could not be conceived. This "necessary" systematic scheme, which must be "a constituent part" of any imaginable developed legal system, is but the Roman division into obligations ex contractu, obligations ex delicto and obligations ex uariis causarum figuris, in which the third category is obviously a catch-all. In trying to fit our law into this necessary scheme, we find three types of cases must go in the third: (a) Duties or liabilities attached by law to a relation, (b) duties imposed by law to prevent unjust enrichment, (c) duties involved in an office or calling. In the third of these our Anglo-American procedure allows recovery either ex delicto or ex contractu. In the second our law sometimes goes on a property theory of constructive trust. In the first duties are sometimes sanctioned affirmatively by conferring legal powers or negatively by legal non-restraint of natural powers, as in the law of domestic relations, where the wife has a power to pledge the husband's credit for necessaries and the law does not interfere with the parent's administering reasonable "correction" to the child. Are we to say that these dogmatic departures of our law from the Roman scheme are inconceivable or that because of them our law is not matured or was not "evolved in a refined community?" Or are we to say that Austin derived his systematic ideas, not from scientific study of English law, but from scientific study of Roman law in a German university? Are we to say that we cannot "imagine coherently" a system of law which enforces warranties indifferently ex contractu or ex delicto as our law does, or which goes further and applies the contract measure of damage ex delicto as does the law of Massachusetts? But enough of this. What we have here is not any necessary distinction. It is rather what Austin calls a "pervading notion," to be found generally in the systematic ideas of developed legal systems by derivation from the Roman books. Roman law may have a contractual conception of obligation ex delicto—thinking of the delict as giving rise to a debt—and the common law a delictual conception of liability upon contract—thinking in terms of recovery of damages for the wrong of breaking a promise—without much difference in the ultimate results. The fundamental things are not tort and contract but justifiable assumptions as to the mode in which one's fellow men will act in civilized society in many different situations of which aggression and undertaking are but two common types.
Returning to our second postulate of due care in affirmative courses of conduct, we may note that in the society of today it is no less fundamental than the postulate of no intentional aggression. Aggression is the chief if not the only form of anti-social conduct in a primitive society. Indeed, a Greek writer on law and politics of the fifth century B. C. knew of no other subject of legal precepts. But with the development of machinery and consequent increase in human powers of action, the general security comes to be threatened quite as much by the way in which one does things as by what he does. Carelessness becomes a more frequent and more serious source of danger to the general security than aggression. Hence a set of nominate delicts requiring dolus is supplemented by a theory of culpa. Hence a set of nominate torts, characterized by intentional aggression, is supplemented by liability for negligence, and the latter becomes the more important source of legal liability in practice.
Must we not recognize also a third postulate, namely, that men must be able to assume that others, who keep things or maintain conditions or employ agencies that are likely to get out of hand or escape and do damage, will restrain them or keep them within proper bounds? Just as we may not go effectively about our several businesses in a society dependent on a minute division of labor if we must constantly be on guard against the aggressions or the want of forethought of our neighbor, so our complex social order based on division of labor may not function effectively if each of us must stay his activities through fear of the breaking loose or getting out of hand of something which his neighbor harbors or maintains. There is danger to the general security not only in what men do and the way in which they do it, but also in what they fail to do in not restraining things they maintain or agencies they employ which may do injury if not kept strictly in hand. The general security is threatened by wilful aggression, by affirmative action without due regard for others in the mode of conducting it, and by harboring and maintaining things and employing agencies likely to escape or to go out of bounds and do damage. Looked at in this way, the ultimate basis of delictal liability is the social interest in the general security. This interest is threatened or infringed in three ways: (1) Intentional aggression, (2) negligent action, (3) failure to restrain potentially dangerous things which one maintains or potentially dangerous agencies which one employs. Accordingly these three are the immediate bases of delictal liability.