Custom which does not fulfil all the requirements hitherto considered by us does not necessarily fail of all legal effect. It cannot, indeed, operate as a source of law by virtue of its own inherent authority. Yet it may nevertheless become legally operative by being incorporated into agreements, through the tacit consent of those who make them. Customs so operative may be distinguished as conventional. It is a rule of English law, as well as of other systems, that where a contract is made in any matter in respect of which an established custom exists, it must be interpreted by reference to that custom, and the parties must be deemed to have intended (in the absence of any expression of contrary intent) to adopt it as one of the terms of their agreement. In contractibus tacite veniunt ea quae sunt moris et consuetudinis.[[146]]
For example, if a lease of agricultural land is made in any district in which there are established usages as to the mode of agriculture and as to the relative rights and liabilities of landlord and tenant, the parties must be taken to have agreed to those usages as terms of the bargain, unless they have expressly or implicitly shown an intention to the contrary. In the same way, a mercantile contract must be taken to incorporate any usages of trade which are relevant to its subject-matter. In this manner customs which are not in themselves authoritative as sources of law or rights may become indirectly operative through the added authority of agreement. But the law and rights so produced are in reality conventional and not customary. It is sometimes not easy to determine whether a custom is operative directly and as such, or only indirectly as accessory to a contract, and the distinction has not always been sufficiently adverted to.
§ 59. Theories of Customary Law.
So far we have been concerned rather with those positive rules of English law which determine the validity and effect of custom, than with the abstract theory of the matter. This portion of juridical theory, however, has been the subject of considerable discussion and difference of opinion, and it is not free from apparent difficulties. We have to consider two opinions which differ materially from that which is here accepted as correct. The first of these is a characteristic feature of foreign and more especially of German jurisprudence, its reception being chiefly due to the influence of Puchta and Savigny. It essentially consists in this, that custom is rightly to be considered as a formal, and not merely as a material source of law. According to this doctrine, custom does itself confer the force and validity of law upon the principles embodied in it. It does not merely provide the material contents which derive their validity as law from the will of the state. It operates directly through its own inherent force and authority; not indirectly by reason of its recognition and allowance by the supreme authority and force of the state. The will of the state is not admitted to be the exclusive source of legal validity. It has no pre-eminence in this respect above the will of the people, as manifested in national usage. Custom is regarded as the expression of the national will and conscience, and as such it confers immediately the authority of law upon all principles approved by it. The will of the state is simply a special form of the popular will, and these are of equal authority. Customary law, therefore, has an existence independent of the state. It will be enforced by the state through its courts of justice because it is already law; it is not because it will be so enforced, that it is law.
Thus it is said by Arndts,[[147]] a German jurist of repute: “Customary law contains the ground of its validity in itself. It is law by virtue of its own nature, as an expression of the general consciousness of right, not by virtue of the sanction, express or tacit, of any legislature.” So Windscheid:[[148]] “In custom is manifested the conviction of those who use it that such custom is law (Recht), and this conviction is the source of the authority and validity of customary law. For the ultimate source of all positive law is national reason.... And this national reason can establish law in two different ways, namely, mediately and immediately. Mediately, through representation, it creates law by means of legislation. Immediately, it creates law by means of custom.”
Notwithstanding the credit of the great names by which this theory is sanctioned, it is rightly and all but unanimously rejected by English jurists. Custom is a material, not a formal source of law. Its only function is to supply the principles to which the will of the state gives legal force. Law is law only because it is applied and enforced by the state, and where there is no state there can be no law. The popular conscience is in itself as powerless to establish or alter the law of the land, as it is to deal in like fashion with the laws of nature. From custom, as from any other source, the state may draw the material contents of the rules to which it gives the form and nature of law, but from no other source than the will of the state itself can this form or nature be itself derived.
A second theory of customary law is that which we may term the Austinian, as having been advanced by Austin, and generally received by his followers. Austin rightly repudiates the German theory on the ground, already indicated, that custom is not a formal but merely a material source of law. The rejection of this and other allied confusions of thought is, indeed, one of the great services which he and his school have rendered to legal science. Nevertheless his own theory cannot be regarded as wholly satisfactory. For he in his turn confounds the legal and the historical sources of the law, and erroneously regards custom as one of the latter, rather than as one of the former. He considers that the true legal source of customary law is to be found in the precedents in which customs receive for the first time judicial recognition and enforcement. Customary law is for him simply a variety of case-law. It is case-law in which pre-existing customs have served as the historical sources from which the courts have drawn the matter of their decisions. The judges are conceived as basing their judgments upon custom, just as, on other occasions, they may base them on Justinian’s Digest or on the law of nature. It follows from this that a custom does not acquire the force of law until it has actually come to the notice of the courts and received judicial approval and application. If it is never disputed, and therefore never requires enforcement, it never acquires the force of law at all. “Law styled customary,” says Austin,[[149]] “is not to be considered a distinct kind of law. It is nothing but judiciary law, founded on an anterior custom.”
This opinion, however, seems inconsistent with the established doctrines of English law as to this matter. Custom is law not because it has been recognised by the courts, but because it will be so recognised, in accordance with fixed rules of law, if the occasion arises. Its legal validity is not dependent on the accidents of litigation. A custom does not wait to put on the nature of law until it has been actually enforced by the courts, any more than an Act of Parliament or an agreement is destitute of legal efficacy until it has required and received judicial recognition. This recognition may make a custom part of the common law, as being thereafter entitled to judicial notice, but it was part of the law already. The Austinian theory forgets that the operation of custom is determined by fixed legal principles, just as much as the operation of precedent itself. These two are co-ordinate legal sources, and each operates independently of the other. Custom does not enter the law through precedent, any more than precedent through custom. A custom is taken as the ground of a judicial decision, just as an Act of Parliament is so taken. In each case the law has been already made, and the judicial decision merely applies it.
§ 60. Custom and Prescription.
The relation between custom and prescription is such as to demand attention here, although the theory of the latter will receive further consideration in another place. Custom is long usage operating as a source of law; prescription is long usage operating as a source of rights. That all the lands in a certain borough have from time immemorial, on the death of an owner intestate, descended to his youngest son, is a custom, and is the source of a rule of special and customary law excluding in that borough the common law of primogeniture. But that John Styles, the owner of a certain farm, and all his predecessors in title, from time immemorial have used a way over the adjoining farm is a prescription, and is the source of a prescriptive right of way vested in John Styles.