§ 57 The Requisites of a Valid Custom
In order that a custom may be valid and operative as a source of law, it must conform to certain requirements laid down by law. The chief of these are the following:—
1. Reasonableness.—A custom must be reasonable. Malus usus abolendus est.123 The authority of usage is not absolute, but conditional on a certain measure of conformity with justice and public utility. It is not meant by this that the courts are at liberty to disregard a custom whenever they are not satisfied as to its absolute rectitude and wisdom, or whenever they think that a better rule could be formulated in the exercise of their own judgment. This would be to deprive custom of all authority, either absolute or conditional. The true rule is that a custom, in order to be deprived of legal efficacy, must be so obviously and seriously repugnant to right and reason, that to enforce it as law would do more mischief than that which would result from the overturning of the expectations and arrangements based on its presumed continuance and legal validity. We shall see, when we come to discuss the theory of precedent, how the authority of judicial decisions is, in general, similarly conditional rather than absolute; a precedent which is plainly and seriously unreasonable may be overruled instead of followed. We are told in the old books that a similar rule obtains in respect of the authority of acts of Parliament themselves. It was once held to be good law, that an unreasonable act of Parliament was void.124 This, indeed, is no longer so; for the law-creating authority of Parliament is absolute. Certain forms of subordinate legislation, however, are still subject to the rule in question; an unreasonable by-law, for example, is as void and unauthoritative as an unreasonable custom or precedent.
2. Opinio necessitatis.—The second requisite of a valid custom is that which commentators on the civil law term opinio necessitatis.125 By this is meant the conviction on the part of those who use a custom that it is obligatory, and not merely optional.126 Custom, merely as such, has no legal authority at all; it is legally effective only because and in so far as it is the expression of an underlying principle of right approved by those who use it. When it is based on no such ethical conviction or opinio necessitatis—when those who use it hold themselves free to depart from it if they will—it is of no legal significance. The only customs which are a source of law are those which are observed by the community as determining the rights and duties of its members.
3. Conformity with statute law.—The third condition of legal validity is that a custom must not be contrary to an act of Parliament. We shall see that certain forms of custom possess not merely constitutive, but also limited abrogative power, being capable of derogating from the old law, as well as of creating new. But no custom of any sort is of any validity as against statute law. The authority of legislation is in English law higher than that of custom. By no length of desuetude can a statute become invalid, and by no length of contrary usage can its provisions be modified in the smallest particular. The common law will yield to immemorial usage, but the enacted law stands for ever.127
It must not be supposed that this rule is one of necessity, derived by logical inference from the nature of things. It is nothing more than a positive principle of the law of England, and a very different rule was adopted by Roman law,128 and by the various Continental systems derived from it. There the recognised maxim is Lex posterior derogat priori. The later rule prevails over the earlier, regardless of their respective origins. Legislation has no inherent superiority in this respect over custom. If the enacted law comes first, it can be repealed or modified by later custom; if the customary law is the earlier, it can be similarly dealt with by later enacted law. “If,” says Savigny,129 “we consider customs and statutes with respect to their legal efficacy, we must put them on the same level. Customary law may complete, modify, or repeal a statute; it may create a new rule, and substitute it for the statutory rule which it has abolished.” So Windscheid:130 “The power of customary law is equal to that of statutory law. It may, therefore, not merely supplement, but also derogate from the existing law. And this is true not merely of rules of customary law inter se, but also of the relations of customary to statute law.”131
4. Immemorial antiquity.—The fourth requisite of the validity of a custom relates to the length of time during which it has been established. Here it is necessary to distinguish between two kinds of customs, namely, those which are general—the customs of the realm, prevailing throughout the whole territory governed by the legal system—and those which are local, being limited to some special part of the realm.132 The rule of English law with respect to the necessary duration of a custom is that one which is merely local must have existed from time immemorial. In the case of other customs, however, there is no such requirement. It is there sufficient that the usage should be definitely established, and its duration is immaterial. A local custom must make up for the limited extent of its application by the long duration of its existence, but other customs derive from their generality such a measure of authority as does not require to be supplemented by length of days.
We shall see later, how the idea of immemorial custom was derived by the law of England from the canon law, and by the canon from the civil law. Time immemorial, or time whereof the memory of man runs not, means in the civil and canon law, and in the systems derived therefrom, and originally meant in England also, time so remote that no living man can remember it, or give evidence respecting it. Custom was immemorial, when its origin was so ancient that the beginning of it was beyond human memory, so that no testimony was available as to a time when it did not as yet exist.133 In the thirteenth century, however, a very singular change took place in the meaning of the term. The limit of human memory ceased to be a question of fact, and was determined by a very unreasonable rule of law which still remains in force. In consequence of the interpretation put by the judges upon the Statute of Westminster I., passed in the year 1275, it became an established legal principle that the time of memory reached back as far as the commencement of the reign of Richard I. and no further. From that day to this the law has remained unaltered. The discordance between the memory of man as it is in fact, and as it is in law, has been steadily growing with the lapse of years, so that at the present day the law of England imputes to living men a faculty of remembrance extending back for seven centuries. There is perhaps no more curious example of the conservatism of our law.134
The rule, therefore, that a particular custom is invalid unless immemorial means in practice this: that if he who disputes its validity can prove its non-existence at any time between the present day and the twelfth century, it will not receive legal recognition. It is not necessary for the upholder of it to prove affirmatively its existence during the whole of that period. If he can prove that it has existed for a moderate period, say twenty years, from the present day, this will raise a presumption of its immemorial antiquity, which must be rebutted by him who disputes it.135
It is not difficult to understand the reason which induced the law to impose this stringent limitation upon the efficacy of local customs. It was designed in the interests of a uniform system of common law for the whole realm. Had all manner of usages been recognised without any such limitation, as having the force of special law, the establishment and maintenance of a system of common law would have been rendered all but impossible. Customary laws and customary rights, infinitely various and divergent, would have grown up so luxuriantly, as to have choked that uniform system of law and rights which it was the purpose of the royal courts of justice to establish throughout the realm.136
Origin of the rule as to time of memory.—The requirement of immemorial antiquity was introduced into the English law courts of the twelfth or thirteenth century from the canon law. In two respects the Canonists developed and rendered more definite the somewhat vague and indeterminate theory of customary law which we find in the writings of the Roman lawyers. In the first place, clear recognition was accorded to the distinction between jus commune and consuetudines, the former being the common, general, or written law of the whole Church, while the latter consisted of the divergent local and personal customs which were added to, or substituted for the jus commune in particular places or in respect of particular persons. This nomenclature, with the conceptions expressed by it, passed from the canon law to the law of England.
In the second place the Canonists attempted to supply a defect of the civil law by laying down a fixed rule as to the necessary duration of customs. They determined that no consuetudo was to be held valid, so as to derogate from the jus commune, unless it was praescripta, that is to say, unless it had endured during the legal period of prescription. Consuetudo praescripta praejudicat juri communi.137
What, then, was the period of prescription thus required? On this point we find no agreement among the doctors, for there were several different forms of prescription known to Roman law, and there was no unanimity among the Canonists in the selection of any one of them as a test of the validity of custom. Many favoured the adoption of the ordinary decennial prescription of Roman land law, and held that a custom must have endured for ten years at least, but need have lasted no longer.138 Others demanded forty years, since this is the prescription required as against the Church by the legislation of Justinian.139 At one time, however, there was a widely held opinion that the true time of prescription required to enable a custom to derogate from the common law of the Church was time immemorial. Illa consuetudo praejudicat juri, cuius non exstat memoria hominum.140
This conception of time of memory as a period of prescription was derived from the civil law. Immemorial prescription was there a mode of acquiring servitudes. Ductus aquae cuius origo memoriam excessit, jure constituti loco habetur.141 The Canon law adopted this rule, and made a more extensive use of it. Immemorial prescription became a supplementary mode of acquisition, available in all cases in which there was no shorter period of prescription to which a claimant might have recourse. From the canon law it passed into the laws of France, Germany, and England.142
As already stated, then, many Canonists recognised time immemorial not merely as a period of prescription, but as a condition of the validity of customary law. Suarez, writing at the end of the sixteenth century, tells us, indeed, in the course of an exhaustive examination of the theory of customary law, that in his day this doctrine was no longer received.143 Long before Suarez, however, it had established for itself a secure place in the law of England. The canonical principles of consuetudo rationabilis et praescripta and of tempus immemoriale were in the thirteenth century at the latest incorporated in our legal system by those ecclesiastical lawyers who laid the foundations of it. This, indeed, was the only form of prescription which obtained recognition from the common law. We find the rule settled with perfect definiteness in the earliest Year Books of Edward I.144
5. Conformity with the common law.—The fifth and last requirement of a valid custom is that, unless immemorial, it must be consistent with the common law. That it must be consistent with statute law is, as we have already seen, a rule applicable to all customs whatever, whether immemorial or not. That it must be consistent with the common law is a rule applicable only to recent customs, and not to those which have the prestige and authority of immemorial antiquity. Modern custom possesses constitutive, but no abrogative power; it must operate in the spaces left vacant by the law already established; it may supplement the law, but cannot derogate from it. Immemorial custom, on the other hand, can destroy as well as create, so far as the common law is concerned; though as against the statute law it is as powerless as the most ephemeral usage.145
The combined effect of the various rules which we have considered is to render custom less and less important as a source of new law. As the legal system develops, the sphere within which custom is operative grows gradually smaller. For, in the first place, custom cannot derogate from statute law, and this latter tends progressively to absorb into itself the whole of the common law. In the second place, the requirement of immemorial antiquity precludes local custom from operating as an instrument of fresh legal growth. Such customs may now be proved and applied for the first time, but they cannot now for the first time come into existence. In the third place, all recent custom must be consistent with the law as already established, whether common or statutory. As the law develops and completes itself, therefore, there is less and less room left for the constitutive operation of custom. There are fewer vacancies within which customary law may grow. It is for this reason that the growth of general customary law has already all but ceased. Until a comparatively recent date, a great part of mercantile law was so imperfectly developed as to leave very considerable scope for the operation of mercantile custom. The law as to negotiable instruments, for example, was chiefly customary law. But at the present day our mercantile law is so complete that it is only in comparatively rare cases that the custom of merchants has any opportunity of serving as the ground of new principles.