192 HARVARD LAW REVIEW. be not in fault), or there may be honest and serious diversity of opinion as to what is really due. Then, although parties do not desire their agreements to be broken, it would be incorrect to say that they never contemplate it; for they often make special provision for such an event, and even fix beforehand the amount or scale of the compensation to be paid. Thus it appears that the duty of compensation in case of non-performance is fairly regarded as incident and supplementary to the primary duty of performance. In practice and practical exposition it would not be convenient, indeed it would hardly be possible, to separate the legal results of breach of contract from the rules determining what are the duties and rights of the parties before any breach. From the point of view of a modern lawyer conversant with modern habits of life and business it may well seem that the distinc- tion between duties and rights prescribed by the parties themselves, and those prescribed by the law, is really of greater importance than that which looks only to their impersonal or personal character. The relations recognized by law can be divided, with no great apparent inequality as to quantity or value in human affairs, into those which arise from contract (or voluntary dispositions analogous to con- tract) and those which are independent of contract. And the dis- tinction is at first sight so clear as to seem unmistakable. But the history of the law shows us that an absolutely clear-cut division is not to be had, even so, between the facts and relations to which our rules apply. The description of legal duties and rights as being in rem or in personam is usually and correctly said to be unauthor- ized by classical Latin usage. Roman lawyers spoke of " actiones," not "jura," being in rem or iji personam. But it should be remem- bered that in Roman usage " action " included what we now call a " right of action," any determinate claim to some form of legal redress. " Action " was defined as a man's right of obtaining by process of law what is due to him, not as the process itself " Nihil aliud est actio quam jus quod sibi debeatur iudicio persequendi." ^ Hence the modern usage is not so wide apart from the Roman as it appears at first sight to be. A classical division accepted by almost all systematic writers is that of public and private law. No rule of law can be said, in the last resort, to exist merely for the benefit of the State or merely for the benefit of the individual. But some departments of legal rules 1 Celsus, D 44. 7, De Obi et Act. 51.
