§ 65. The Disregard of a Precedent.
In order that a court may be justified in disregarding a conditionally authoritative precedent, two conditions must be fulfilled. In the first place, the decision must, in the opinion of the court in which it is cited, be a wrong decision; and it is wrong in two distinct cases: first, when it is contrary to law, and secondly, when it is contrary to reason. It is wrong as contrary to law, when there is already in existence an established rule of law on the point in question, and the decision fails to conform to it. When the law is already settled, the sole right and duty of the judges is to declare and apply it. A precedent must be declaratory whenever it can be, that is to say, whenever there is any law to declare.
But in the second place, a decision may be wrong as being contrary to reason. When there is no settled law to declare and follow, the courts may make law for the occasion. In so doing, it is their duty to follow reason, and so far as they fail to do so, their decisions are wrong, and the principles involved in them are of defective authority. Unreasonableness is one of the vices of a precedent, no less than of a custom and of certain forms of subordinate legislation.
It is not enough, however, that a decision should be contrary to law or reason, for there is a second condition to be fulfilled before the courts are entitled to reject it. If the first condition were the only one, a conditionally authoritative precedent would differ in nothing from one which is merely persuasive. In each case the precedent would be effective only so far as its own intrinsic merits commended it to the minds of successive judges. But where a decision is authoritative, it is not enough that the court to which it is cited should be of opinion that it is wrong. It is necessary in innumerable cases to give effect to precedents notwithstanding that opinion. It does not follow that a principle once established should be reversed simply because it is not as perfect and rational as it ought to be. It is often more important that the law should be certain than that it should be ideally perfect. These two requirements are to a great extent inconsistent with each other, and we must often choose between them. Whenever a decision is departed from, the certainty of the law is sacrificed to its rational development, and the evils of the uncertainty thus produced may far outweigh the very trifling benefit to be derived from the correction of the erroneous doctrine. The precedent, while it stood unreversed, may have been counted on in numerous cases as definitely establishing the law. Valuable property may have been dealt with in reliance on it; important contracts may have been made on the strength of it; it may have become to a great extent a basis of expectation and the ground of mutual dealings. Justice may therefore imperatively require that the decision, though founded in error, shall stand inviolate none the less. Communis error facit jus.[[161]]
“It is better,” said Lord Eldon, “that the law should be certain than that every judge should speculate upon improvements in it.”[[162]]
It follows from this that, other things being equal, a precedent acquires added authority from the lapse of time. The longer it has stood unquestioned and unreversed, the more harm in the way of uncertainty and the disappointment of reasonable expectations will result from its reversal. A decision which might be lawfully overruled without hesitation while yet new, may after the lapse of a number of years acquire such increased strength as to be practically of absolute and no longer of merely conditional authority. This effect of lapse of time has repeatedly received judicial recognition.
“Viewed simply as the decision of a court of first instance, the authority of this case, notwithstanding the respect due to the judges who decided it, is not binding upon us; but viewed in its character and practical results, it is one of a class of decisions which acquire a weight and effect beyond that which attaches to the relative position of the court from which they proceed. It constitutes an authority which, after it has stood for so long a period unchallenged, should not, in the interests of public convenience, and having regard to the protection of private rights, be overruled by this court except upon very special considerations. For twelve years and upwards the case has continued unshaken by any judicial decision or criticism.”[[163]]
“When an old decided case has made the law on a particular subject, the Court of Appeal ought not to interfere with it, because people have considered it as establishing the law and have acted upon it.”[[164]]
The statement that a precedent gains in authority with age must be read subject to an important qualification. Up to a certain point a human being grows in strength as he grows in age; but this is true only within narrow limits. So with the authority of judicial decisions. A moderate lapse of time will give added vigour to a precedent, but after a still longer time the opposite effect may be produced, not indeed directly, but indirectly through the accidental conflict of the ancient and perhaps partially forgotten principle with later decisions. Without having been expressly overruled or intentionally departed from, it may become in course of time no longer really consistent with the course of judicial decision. In this way the tooth of time will eat away an ancient precedent, and gradually deprive it of all its authority. The law becomes animated by a different spirit and assumes a different course, and the older decisions become obsolete and inoperative.
To sum the matter up, we may say that to justify the disregard of a conditionally authoritative precedent, it must be erroneous, either in law or in reason, and the circumstances of the case must not be such as to make applicable the maxim, Communis error facit jus. The defective decision must not, by the lapse of time or otherwise, have acquired such added authority as to give it a title to permanent recognition notwithstanding the vices of its origin.