The nature of a legal presumption, also, had been misconceived by several American courts. It had been treated as evidence of facts.[Footnote: Coffin v. United States, 156 United States Reports, 432.] Professor J. B. Thayer, in his "Preliminary Treatise on Evidence,"[Footnote: Pages 337, 566-575.] argued so forcibly against this view that in at least one State a decision in which it had been taken has been formally overruled.[Footnote: Vincent v. Mutual Reserve Fund Life Association, 77 Connecticut Reports, 281, 291; 58 Atlantic Reporter, 963.]

The Court of Appeals of New York once held in a carefully prepared opinion that a railroad might be built along the shore of a navigable river, under authority from the State, without first making compensation to the riparian proprietors, whose access to the waters might thus be obstructed.[Footnote: Gould v. Hudson River Railroad Co., 6 New York Reports, 522.] In a text-book written by Chief Justice Cooley, this decision was justly criticised,[Footnote: Cooley on Constitutional Limitations, 670.] and not long after the publication of that work it was formally overruled.[Footnote: Rumsey v. New York and New England Railroad Co., 133 New York Reports, 79; 30 Northeastern Reporter, 654; 15 Lawyers' Reports Annotated, 618.] It is safe to say that its fate was largely the result of the comments thus made by a distinguished jurist, whose only motive could be to maintain the integrity and consistency of legal science.

The general doctrine of the courts, which is commonly expressed by the rule "stare decisis," was never better stated than by Chief Justice Black of Pennsylvania, in these words:

When a point has been solemnly ruled by the tribunal of the last resort, after full argument and with the assent of all the judges, we have the highest evidence which can be procured in favor of the unwritten law. It is sometimes said that this adherence to precedent is slavish; that it fetters the mind of the judge, and compels him to decide without reference to principle. But let it be remembered that stare decisis is itself a principle of great magnitude and importance….

A palpable mistake, violating justice, reason and law, must be corrected, no matter by whom it may have been made. There are cases in our books which bear such marks of haste and inattention, that they demand reconsideration. There are some which must be disregarded, because they cannot be reconciled with others. There are old decisions of which the authority has become obsolete, by a total alteration in the circumstances of the country and the progress of opinion. Tempora mutantur. We change with the change of the times, as necessarily as we move with the motion of the earth. But in ordinary cases, to set up our mere notions above the principles which the country has been acting upon as settled and established, is to make ourselves not the ministers and agents of the law, but the masters of the law and the tyrants of the people.[Footnote: McDowell v. Oyer, 9 Harris' Reports, 423.]

Generally, overruling a former decision is due to a change of circumstances, which has given the court a new view-point. A marked instance of this occurred in 1851, in proceedings before the Supreme Court of the United States. More than a quarter of a century before, a suit in admiralty for seamen's wages on an inland river had been dismissed by the District Court of Kentucky for want of jurisdiction, and on appeal this action had been affirmed. Mr. Justice Story gave the opinion of the court, and said that a court of admiralty could only take cognizance of such a claim when the services were rendered at sea or upon waters within the ebb and flow of the tide.[Footnote: The Thomas Jefferson, 10 Wheaton's Reports, 428.] This was undoubtedly a true statement of what had always been the doctrine of both English and American courts. But out of what did this doctrine spring? From the fact that in England there were no navigable waters except those in which the tide ebbed and flowed, and that in the United States, up to that time, there were none of a different kind which had been largely used for commercial purposes. Twenty years passed. Steam navigation had opened the great lakes and the great rivers of the country to a profitable carrying trade. The day was dawning when the bulk of American shipping was to be employed upon them. A suit in admiralty was brought against a ship for sinking another on Lake Ontario. The defendants put in an answer relying on the doctrine laid down by Story. The District Court overruled it. The case came by appeal to the Supreme Court, and in an opinion by Chief Justice Taney the appeal was dismissed. "The conviction," he said, referring to the opinion of Mr. Justice Story, "that this definition of admiralty powers was narrower than the Constitution contemplated, has been growing stronger every day with the growing commerce on the lakes and navigable rivers of the western States…. These lakes are in truth inland seas. Different States border on them on one side and a foreign nation on the other. A great and growing commerce is carried on upon them between different States and a foreign nation, which is subject to all the incidents and hazards that attend commerce on the ocean. Hostile fleets have encountered on them and prizes been made, and every reason which existed for the grant of admiralty jurisdiction to the general government on the Atlantic seas applies with equal force to the lakes. There is an equal necessity for the instance and for the prize power of the admiralty court to administer international law, and if the one cannot be established neither can the other…. The case of the Thomas Jefferson did not decide any question of property or lay down any rule by which the right of property should be determined…. The rights of property and of parties will be the same by whatever court the law is administered. And as we are convinced that the former decision was founded in error, and that the error, if not corrected, must produce serious public as well as private inconvenience and loss, it becomes our duty not to perpetuate it."[Footnote: The Genesee Chief, 12 Howard's Reports, 443, 451.]

But without any change of circumstances, the proper desire of all American courts to keep their common law in harmony with that of the other States is often sufficient to induce the abandonment of a doctrine once distinctly asserted.[Footnote: City of South Bend v. Turner, 156 Indiana Reports, 418; 60 Northeastern Reporter, 271.] The consistency of American law as a whole is immeasurably more important than the consistency of the law of any single State.

Sometimes a court of last resort treats a doctrine which it had formerly asserted as manifestly unsound and abandons it without stopping to give a reason or even to overrule the decision which first announced it.

Illinois for a long generation adopted the rule that if an injury occurred to one man through the concurring negligence of himself and another, but his negligence was slighter than that of the other, he might hold the latter responsible for the damages suffered.[Footnote: Andrews, "American Law," 255, 1027.] It was not a doctrine justified by the common law nor generally held in this country, and in 1894 the Supreme Court of the State refused to recognize it, with little or nothing more than this brief ipse dixit: "The doctrine of comparative negligence is no longer the law of this court."[Footnote: Lanark v. Dougherty, 153 Illinois Reports, 163; 38 Northeastern Reporter, 892.]

Occasionally a case is overruled because it has been forgotten.