Usages grow up rapidly in new settlements and along frontiers bounded by territory held by savages. Of such usages, under the rulings of the courts, many were soon crystallized into law.

New inventions and new political conceptions in the eighteenth century began to change the face of the civilized world. The common law as to agency had to be adapted to the operations of business corporations; that as to highways to railroads; that as to contracts by mail to contracts by telegram, and later to contracts by telephone. The whole law of master and servant, which for the English people was bottomed on the relation of land-owner and serf, was to be recast. Public assemblies were to be regulated and their proceedings published with greater regard to public and less to private interest.[Footnote: Barrows v. Bell, 7 Gray's Reports, 301; 66 American Decisions, 479.] Along all these lines and many others the American courts have now for nearly three hundred years been quarrying out American law from the mine of the unwritten law of the people within their jurisdiction. It has been their natural endeavor to make each part of the new system of jurisprudence which they were gradually building up harmonious with every other and to give a certain symmetry to the whole. This has forced them to deduce rule from rule and principle from principle with a freedom for which in older countries of settled institutions there is less occasion. The process has gone on during the last fifty years with ever-increasing rapidity, and for two reasons. There have been more novel questions to meet and there has been a greater wealth of suggestion and precedent at command.

Not a little, however, of the development of our unwritten law has been and remains of a local character. This is particularly true of that of the Pacific States, both on account of climatic conditions and historical antecedents.[Footnote: Katz v. Walkinshaw, 141 California Reports, 116.] Chief Justice Field of the Supreme Court of California, afterward so long a member of the Supreme Court of the United States, did both a constructive and a destructive work in shaping the jurisprudence of that State. He found it seated in a land on which certain institutions of civil law origin had been impressed for centuries and into which other institutions of common law origin had been introduced in recent years. His judicial opinions molded these into one mass, rejecting something from each and retaining something from each.[Footnote: Pomeroy, "Some Account of the Work of Stephen J. Field," 38, 45.] Some of the results of his creative touch have been the foundation of decisions in distant States, but most were so dependent on local circumstances and conditions as to be incapable of transplantation.

But as to all questions of general concern which can be answered from analogies drawn from the common law, the judges of each State—and it is the State judiciary on which the burden of developing unwritten law mainly rests—now find in the reported decisions of the courts of last resort in all the other States a fertile source of supply when they are looking for a rule to fit a case for which the ancient law made no direct provision. Keen intellects from the bench, aided perhaps by keener ones from the bar in forty-five different jurisdictions, are discussing the problems of the day as they appear mirrored in litigated causes. What is a new question in one State was set at rest ten years or ten days ago by a judicial decision in another. If the decision was a just and logical deduction from accepted principles of the older law it will probably be followed everywhere. If unjust and illogical, its very faults will serve to guard other courts to better conclusions.

How far judges advance along these paths depends greatly on the character of the bar. A judge rarely initiates anything. He is apt to fall into a mistake if he does. The business which he has to do is brought before him by others. It is brought before him in the best way to throw all possible light upon it, because it is set before him from two opposite points of view by two antagonists, each strenuously endeavoring to detect a flaw in the reasoning of the other. These two men have previously given the subject in controversy much careful thought. What views neither presents are generally not worth presenting. As was said in the preceding chapter, it is only in the plainest case that a judge can properly or safely base his decision on a position not suggested at the bar or as to the soundness of which he has not asked the opinion of the counsel at the hearing.

The development of law, therefore, whether unwritten or written, is primarily the work of the lawyer. It is the adoption by the judge of what is proposed at the bar.[Footnote: See Chap. VI, X.]

There are obvious limits to this power of developing unwritten law. The courts are not to push forward into a place more appropriate for the legislature to occupy.

Mr. Justice Holmes of the Supreme Court of the United States, when Chief Justice of Massachusetts, stated with his usual elegance and force the bounds within which, as it seemed to him, judicial authority should be kept. In a common law suit against a railroad company for damages suffered by an accident on its road, the defendant had asked the trial court to order the plaintiff to submit to an examination of his person by a physician whom it named, for the purpose of determining what injuries he had really suffered. "We agree," said the Chief Justice, "that in view of the great increase of actions for personal injuries it may be desirable that the courts should have the power in dispute. We appreciate the ease with which, if we were careless or ignorant of precedent, we might deem it enlightened to assume that power. We do not forget the continuous process of developing the law that goes on through the courts in the form of deduction or deny that in a clear case it might be possible even to break away from a line of decisions in favor of some rule generally admitted to be based upon a deeper insight into the present wants of society. But the improvements made by the courts are made, almost invariably, by very slow degrees and by very short steps. Their general duty is not to change, but to work out, the principles already sanctioned by the practice of the past. No one supposes that a judge is at liberty to decide with sole reference even to his strongest convictions of policy and right. His duty in general is to develop the principles which he finds with such consistency as he may be able to attain…. In the present case we perceive no such pressing need of our anticipating the legislature as to justify our departure from what we cannot doubt is the settled tradition of the common law to a point beyond that which we believe to have been reached by equity, and beyond any to which our statutes dealing with kindred subjects ever have seen fit to go. It will be seen that we put our decision, not upon the impolicy of admitting such a power, but on the ground that it would be too great a step of judicial legislation to be justified by the necessities of the case."[Footnote: Stack v. New York, New Haven and Hartford Railroad Co., 177 Massachusetts Reports, 155; 58 Northeastern Reporter, 686.]

The theory of judicial power thus stated carries implications that would not be universally accepted. It is intimated that if the necessity had seemed strong enough to call for the order asked for in the trial court it ought to have been granted, although not justified by any settled rule or authoritative precedent, nor by any clear analogy from such a rule or precedent. This is a view taken, though with less caution and qualification, in a work written by the same hand many years before, which is recognized as a legal classic on both sides of the Atlantic. In "The Common Law,"[Footnote: Pp. 35, 36.] after discussing some of the reasons which actuate judges in assuming to unfold the unwritten law, it is stated thus:

The very considerations which judges most rarely mention, and always with an apology, are the secret root from which the law draws all the juices of life. I mean, of course, considerations of what is expedient for the community concerned. Every important principle which is developed by litigation is in fact and at bottom the result of more or less definitely understood views of public policy: most generally, to be sure, under our practice and traditions the unconscious result of instinctive preferences and inarticulate convictions, but none the less traceable to views of public policy in the last analysis…. The truth is that the law is always approaching and never reaching consistency. It is forever adopting new principles from life at one end, and it always retains old ones from history at the other, which have not yet been absorbed or sloughed off. It will become entirely consistent only when it ceases to grow.