190 HARVARD LAW REVIEW. ing a statute. In another sense it is equally true to say with Blackstone that he is merely declaring the existing law. The process in which he is engaged is that of deciding a case, a pro- cess which antedates not merely legislation proper, but the con- ception of law itself. This decision is reached by a course of reasoning from existing data by which, if carried out with entire strictness, he would be as closely limited as if dealing with a statute. The process of dealing with statute law will be referred to later on : what it is important to observe at this point is the growth which necessarily attends the ordinary administration of that body of " written case-law" * which we know as the " common law." 2 (c) This growth of law through its application is neatly brought out by another class of cases, which deal with the functions of the court and jury. To the institution of the jury are due many peculiarities of our system, among others its sharp division between law and fact; and when the question is one of drawing the precise line between these two things, there is an excellent op- portunity of observing how matter is constantly carried over from one side of that line to the other. Take, for example, the impor- tant class of actions for negligence. The standard in those cases 1 See Maine, Ancient Law (9th ed.), 13, 14, where the inaccuracy of the expression " unwritten law " is pointed out. 2 One important source of judicial legislation which is peculiar to the common law must be noticed in passing. In considering the growth which must necessarily result from the application of the law to facts, it has been assumed that the reasoning process under discussion is strictly and logically carried out. But to make this assumption is to look at only one side of the matter. The characteristic method of the common law is, as we have seen, to work along from case to case, dealing with each one as it arises, and dis- claiming any intention of framing a general rule. " However it may be in other cases," the court will say, "on these facts the law is clear." It is common to see extremes at which the law is clear, while the line at which they divide remains obscure until deter- mined by the gradual convergence of the cases. By the slow course of decision just so much law is developed as society requires, and no more ; and later generations are left free to fill in the gaps in accordance with their own notions, as little hampered as may be by those of an earlier age. In the process of reconciling and adjusting the authorities, and extracting from them the principle for which they stand, there is a con- stant tendency to mould it into a form which corresponds with the later conceptions of justice and expediency, and which, though consistent with the actual result of the earlier cases, may be quite foreign to the ideas of those who decided them. The growth of the law, as it is sometimes said, is rational rather than logical. This so-called "flexibility" of the common law is most important, and goes far to explain the success with which it has adapted itself to changing conditions of society. The famous case of Reg. v. Jack- son, 1891, 1 Q. B. 671, denying the husband's right of physical restraint over his wife, is a good instance of this infusion into the law of ideas which would have found little favor with the judges a century ago.
