Chapter 20 Chapter XVI Informal Sources of Law
One of the fundamental errors of legal positivism is that it confines its theory of sources of law entirely or almost entirely to what we call formal sources of law.This error has to be attributed to the fact that legal positivism regards law as a state order, and so it seeks its origins primarily in those formal statutes and orders, which are governed by the legislature, the Promulgated or promulgated by the Constitutional Assembly, courts or administrative agencies.Some positivists, however, especially those in the countries of the Continent, were also willing to give a place in their theories of sources of law to customary law which did not give rise to legal action; A concession to the historical school of law, which enjoyed for a considerable period of time great authority and prestige on the Continent, especially in Germany.
Positivist and analytical jurists are convinced that the system of positive law is a comprehensive, exhaustive, logically self-consistent system of norms that provides answers to all legal questions that courts may face; they They thought they had found an easy and satisfying solution to fundamental problems of legal methodology.But when this belief in the self-sufficiency of the legal system collapsed in the nineteenth and early twentieth centuries, positivist thought ran into a serious dilemma.If the formal sources of law cannot meet the needs of judges in some cases, and if there are situations that cannot be answered by the legal system, what means can judicial judges resort to to make up for this deficiency of the legal system?Accordingly, we shall discuss the approaches proposed by two exponents of legal positivism, John Austin and Hans Kelsen, to address this problem, and the value of their respective arguments Do a discussion.
John Austin pointed out that when positive law cannot provide guidance and reference, all a judge can do is act like a legislator and create new rules that can deal with this problem satisfactorily.Austin also pointed out that in crafting this new rule, judges could appeal to "a variety of sources" including: "customs without the force of law but recognized by society as a whole or by a section of society, standards of international law, and his own views on what the law should be (standards he assumes, general utility, and any other views)".In his view, this judicial law must be retroactive.Judges apply newly enacted rules to past transactions and events, and this can easily lead to a situation where people will be surprised and dismayed "to find that the law imposes on them obligations they never expected."John Austin deeply deplored this state of affairs, and suggested that extensive codification of the law was the most desirable expedient to this intractable problem.
Hans Kelsen took a similar but not identical position to John Austin's on the question of gaps in the law.Like Austin, he admits that positive law embodied in formal sources of law does not definitively answer all the questions courts have to face.It may happen that one party makes a claim or request to the other party in a proceeding and the judge finds that positive law is silent on the question whether the claim or request should be allowed.There may also be other situations where a statute or legal rule may address issues at issue in litigation, but because the wording of the statute or legal rule is extremely vague, whether it can be applied to the ongoing case , will also make judges feel unclear and extremely doubtful.Kelsen discussed the above two situations separately.
According to Kelsen, if the legislator fails to provide for the admissibility of a certain cause of action, then this must be construed as a denial of that claim or claim.Kelsen advocates this solution because he is convinced that no one can require another to do or behave in a way if the latter is not obliged to do so under the rules of positive law. "When the law imposes duties on people to perform specific acts, it permits liberty outside those duties." If desired, then positive law may of course confer on the judge in such a case the power to grant such a request.Kelsen interprets this authorization as allowing judges to try cases contrary to the law. "The judge may apply to the case the law actually in force—that is, by dismissing the action. However, the judge has the power to change the law to suit a particular case, or to make a former legally free People are constrained."
In the second case, that is, when the judge may make two or three interpretations of a norm that lead to different results, the judge can decide which of the above two or three methods is the correct one. What kind of guidance do you get?Kelsen responded to this question by saying that the law does not provide any guidance for judges. "From the point of view of positive law, there is no criterion by which an interpretation may be chosen from among several possible; nor is there what may be called a positive legal method, according to which, Of the several senses of a norm, only one can be shown to be 'correct. regardless of whether such an interpretation would lead to an unreasonable, unfair, or even absurd result.
We believe that the theories of Austin and Kelsen do not accurately reflect the realities of legal life and should be rejected as dangerous and misleading.The view advocated by John Austin that a judge can seek answers to cases not prescribed by formal law from his subjective belief, although this subjective belief may be based on social utility, is obviously incorrect. consideration or "any other" consideration-based.This is because judges have other sources of guidance than formal law (which I discuss in the following chapters); and although these are not as specific and direct as many rules of positive law, Much more is available to judges relying on discretion beyond their control.Nor is Hans Kelsen's assertion that the absence of a law-maker as to the existence or non-existence of a cause of action in a case before a court must be interpreted as a negative norm negating the claim of the plaintiff. of.Courts also frequently enact new remedies similar to those currently in effect without specific authorization from the legislator, and grant relief when the court finds it unjust to deny a remedy.As examples of forms of relief permitted to be granted not authorized by norms of positive law, principally Lord Mansfield's decision in Moses v. Macferlan (which extended the scope of quasi-contract ), and the U.S. Supreme Court's decision in International News Service v. Associated Press, a landmark innovation in unfair competition law.Notwithstanding Kelsen's further assertion that any interpretation of a statute or other source of law sanctioned by the words in a norm must be regarded as correct from the point of view of the law itself, it should be noted that Most serious judges did not pay attention to this suggestion, but regarded it as their duty as a legal institution to adopt an interpretation that conforms to rationality, fairness, and the spirit of the legal system.
The more radical view of legal positivism can easily lead to the nihilism of legal interpretation, which makes the theory of the informal sources of law not only desirable but absolutely necessary.We now know that the system of positive law established by the state is necessarily incomplete and fragmentary, and that its rules are riddled with ambiguities.Some ideas, principles, and standards may be more ambiguous than formal sources of law, but nonetheless provide a degree of normative guidance to court decisions that can only be overcome by appeal to these ideas, principles, and standards. The shortcomings of the positive legal system.If there were no theory of the informal sources of law, then there would be nothing outside the bounds of determinate positive law, except the arbitrariness of the individual judge.If, in situations where formal law fails to guide judges, judges can make laws based on considerations they deem desirable, then, as Austin points out, court decisions will often depend on judges' political conservatism. leaning, or liberal leaning, or radical leaning; depending on whether he believes in tradition or reform in legislation; depends on whether he is a friend of capital or labor; Depends on his subjective beliefs.This is clearly an intolerable situation, as it undermines the very foundations upon which the authority of the law rests and, over time, leads to a judicial crisis.
Roscoe Pound, in his seminal essay "The Theory of Judicial Decision," established some basis for the theory of informal sources of law.His constructive suggestions may serve as the basis for our attempt in this book to discuss the issue more fully; we will classify informal sources, analyze the nature of the various sources and the extent of their legitimate The relationship to formal sources of law is explained.
In discussing the question of whether and to what extent elements of justice and principles of justice have a direct and practical effect on the judiciary and the application of law, we must distinguish between two independent and not necessarily related issues.The first question is whether justice can be regarded as a legal source of praeter legem (other than statutory law).Is it appropriate or even necessary for a judge to appeal to a conception of justice in cases where positive law sources do not provide an answer to the point of law to be decided or where positive law provisions are too ambiguous or open to different interpretations?The second question is: Can there be a situation where a judge is justified in applying the principles of justice of contra legem (as opposed to statute law)?In other words, are judges entitled, in certain circumstances, to refuse to apply a norm of positive law on the grounds that its application would result in fundamental injustice?The first problem is a pervasive and commonplace problem in the judicial process, and a large body of case law can be used to illustrate the meaning and consequences of this problem; while the second problem is a rare problem, it will only occurs in cases of unusual character, and jurists of the positivist school consider that even in this case it is not a question worthy of serious consideration.
The first problem mentioned above arises, for example, when the plaintiff in a legal proceeding makes a claim which he cannot support by citing fully appropriate statute or precedent.In some cases, does the court have just cause—on the basis of justice between the parties, requiring relief to be granted to the plaintiff—to agree to grant him relief?or agreeing with Kelsen that if positive law does not expressly recognize the requirement, it must be interpreted as a decision of the legislator that the requirement does not stand (unless the legislator gives the courts express power to rule in equity), Is this preferable?
In various legal systems, especially in the Anglo-American legal system, there are many judicial precedents, that is, when the positive law does not grant the court any special power to decide "unprovided cases" according to the law of equity, the courts Remedies for new situations on grounds of "natural justice and reason."For example, in the case of "Moses v. Macfarlane" already mentioned above, the Court of Queen's Bench, under the leadership of Lord Mansfield, expanded the scope of application of quasi-contractual remedies.Lord Mansfield stated in that case that if a person accepts money that "justly should not be kept", he is bound "by natural justice and reason" to repay it.In another example, Pavesich v. New England life Ine. Co, the Georgia Supreme Court also allowed the plaintiff to respond to the defendant's invasion of privacy, which was not recognized at the time. The basis for obtaining compensation for damages is that this right is created according to "natural nature", and it should be regarded as a legal right established according to the concept of natural justice.In Woods v. Lancet, the New York State Court of Appeals agreed to award damages to a baby for injuries sustained in its mother's womb while she was nine months pregnant.Rejecting earlier precedent, the Court's avowed purpose was to bring the common law into line with the requirements of justice.
In ancient Roman law, the consuls sometimes granted actions in factum (actiones in factum), with the aim of bringing justice to individual cases in which neither Roman private law nor the pardons of previous consuls provided a remedy. .In modern Roman law jurisdictions, such as Germany, the Supreme Court has also created certain causes of action that are not directly recognized by the German Civil Code.Accordingly, the court affirmed the principle that those who, after making an offer or commencing contract negotiations with others, are liable for negligent or culpable conduct in connection with such an offer or negotiations, whether or not they ultimately An agreement was reached (culap in contrahendo).The court also established certain non-statutory remedies for certain violations in the performance of contractual agreements.
Judges' reliance on notions of justice may be more prevalent in cases that do not involve remedies for new situations.We can find such judgments both in the common law system and in other legal systems.For example, in the case of Valentini v. Canali, a minor sued for the recovery of the money he had paid under a contract for the rent and purchase of furniture.This demand for repayment of money is based on the assumption that contracts entered into by minors for the supply of goods are wholly void under statute.In reality, however, the plaintiff had lived in the house and used the furniture for several months.However, the Court of Queen's Bench refused to accept this action and pointed out that "after a minor has paid for an item and has consumed or used the item, he then asks to recover the money he paid. is contrary to natural justice." In Maclean v. The workers' Union, the Chancery of the Supreme Court held that if a person In order to cause the expelled person to bring an action against him against the institution, he must be given a reasonable opportunity under the "principles of natural justice" to be heard so that he can defend himself against the charges brought by the expelled person and explain his the reason for this behavior. In 1972, the South Carolina Supreme Court struck down the statute transferring a freehold real estate title from a decedent's legal heir and conferring it on a son as heir in second order because it violated " Just right and reason".The Utah Supreme Court stated in 1944 that it had the authority to issue a stay order prohibiting lower courts from commencing proceedings in matters over which it had earlier jurisdiction, with the aim of preventing a "clear and irremediable injustice."
In the field of conflict of laws, general considerations of fairness and justice have played a particularly important role in the development of this branch of law.Thus, the decision of the Mexican court in Banco Minero v. Ross was rejected by the United States court because, in the view of the United States court, despite the important factual question, the defendant's right to a defense was arbitrarily and unjustly denied.Sometimes, when a country's court finds that its own country's law does not provide for the relevant issues, while another country's legal rules are reasonable and just, the country's courts will apply the foreign law in cases that should be accepted under its own law rule.As Mr. Justice Cardoso pointed out, in the development of common law, many gaps were filled by borrowing from Roman law or other legal systems.
Considerations of justice can also weigh decisively when two principles of positive law or two judicial precedents pointing in different directions and leading to different outcomes are logically applicable to a case.Mr. Justice Cardoso, dealing with this issue, cited the case of Riggs v. Palmer to illustrate this conflict.The case ruled that if a testamentary heir murdered the testator, he could not be granted the property bequeathed to him.The conditions of the will, however, and the statutes governing the validity of the will and the transfer of property, clearly favored the murderer's right of inheritance.At the other end of the scale, of course, is the principle that one is not allowed to profit by deliberate crime, and one is not allowed to take possession of property by crime.Two judges on the New York State Court of Appeals found that the language of the applicable statutes was so clear that they were reluctant to depart from the language of those statutes.The majority of judges, however, held that the letter of the statute should in this case be subject to the higher force of equitable principles.Such a choice between two conflicting legal principles is undoubtedly governed by a strong sense of justice, which thus provides the ultimate source of resolution of the problem. "Demands based on the prevailing views of justice and public morality are among the most powerful constitutive forces in the law-making process of the courts."
Courts have also consistently turned to considerations of justice when interpreting ambiguous provisions in constitutional and regulatory documents.Thus, when the U.S. Supreme Court interpreted the Due Process Clause of the Fourteenth Amendment to the U.S. Constitution—the wording of which meant little to nonlegislators—the provisions of the Federal Bill of Rights The safeguarding provisions of the "fundamental principles of liberty and justice" must be observed by state laws and judicial procedures as a necessary condition of due process.Through these decisions, the rights to free speech and association, freedom of religion, the right to a defense in death penalty cases, and the right to a fair trial have all been recognized as essential to justice in our form of society and government less protection.
From the above examples, we must draw the conclusion that the concept of justice is widely used by the judiciary and plays a prominent role in the trial of controversial cases.This should be considered a desirable and desirable attitude to be adopted by anyone who regards the law as being used to achieve social peace without ignoring or sacrificing the basic provisions and requirements of justice. An attitude one would adopt when creating a system of stability, stability and order.In the above-discussed case and others like it, the judges were not governed by that irrational, meaningless, and wholly subjective conception of justice which, according to some positivists, The meaningless, meaningless and entirely subjective conception of justice is precisely the only content of justice.In fact, it is entirely possible for people to interpret the results in the above cases in a rational way and to justify them according to objective measures; we can also think that the above cases have been widely agreed.Courts will be willing to grant new claims or defenses on grounds of fundamental justice and fairness, especially where one end of the scale is overweight or the need for relief is clear and strong.
Of course, the work of judges in terms of achieving an objective standard of justice and achieving coordination and integration between the needs of stability and the needs of justice cannot be accomplished overnight.In the process of enforcing the law, there will always be situations where the requirements of legal certainty conflict with the requirements of justice, or when a judge must make a clear choice between two opposing values.As regards the general case—with regard to certain rare exceptions to which we shall discuss in the following chapters, the judge must apply the substantive and express orders of the Constitution and statutes, even if he is convinced that they are inconsistent or inconsistent with the Again in line with today's basic concept of justice.The above-mentioned situation may occur in the following two situations, one is when a single independent positive law clearly requires a specific solution, and the other is when various positive norms are compared and in the framework of the whole system. Consideration of their relationship must point to a situation which is a unique way of dealing with legal problems.In other words, when positive legal provisions provide a frame of reference for order, judges are usually bound by it and cannot deviate from it for justice.
It should be emphasized, however, that the situation in which a legal result can be clearly derived from the logical model of a positive law institution or the general spirit running through positive law provisions does not occur as often as some commentators assume.A judge often wonders whether he should extend a rule of positive law to cases not directly regulated by it, or whether he should confine it to the circumstances for which it was intended.In this case, the judge need not take Kelsen's advice into account, that is, from a legal point of view, whether he resorts to analogy (extending a principle to the case in question) or to argumentum e contrario (which would lead to the conclusion that the facts of a case are beyond the purview of a formal principle and thus cannot be regulated by that principle), would make no difference, instead he should let justice consider play a greater role.For example, a court may be confronted with the question of whether the principle of sovereign immunity should be extended to the conduct of officials of state-owned corporations, even though it is firmly established in the legal system and clearly applies to official Behavior.Recognizing, in deciding this question, the grave injustice to which this principle of sovereign immunity would result in the remedy of wrongful conduct by government officials, courts may be legitimately induced to restrict the principle strictly to among those cases which have been established by authority.
If positive law is wholly incapable of resolving the problems before the courts, then standards of justice must play a role in formulating a satisfactory solution to the dispute.Not without regret, the thought process leading to the adoption of the rules of justice appropriate to solving the problem in an appropriate way lends itself to a very limited and rather general description.What is attributable to a party can often only be ascertained in the circumstances of a particular case.Although it is possible to objectively rationalize a result, this rationalization cannot always be achieved in a theoretical and dogmatic manner, but must be formulated in the context of a specific problem.Giving individuals the greatest range of desire to claim rights may have to be balanced against arguments for the public good.In addition, considerations of justice should often be paired with supporting arguments based on other informal sources of law: public policy, social orientation, custom, and accepted moral standards.
In the minds of judges, the desire to avoid a complete break with the past sometimes overwhelms the desire to achieve justice between the parties.Although the court may have good reason to support a new remedy or a new defense, the court may legitimately hold that if the action seeks a relief or defense that is different from currently available remedies or defenses resemblance, it would constitute a revolutionary and unprecedented innovation in law, so that courts cannot act in this way without legislative authority.This argument is of particular importance in situations where, for example, the scale of justice is not sinking at the top, or where there are simultaneously a range of options for solving a problem.Sometimes it may be necessary to lay down rules or restrictions for the enjoyment of a new right, or to establish an executive body for exercising it.In these cases, courts will often take the position that the issue must be left to the legislature.
We must now turn to the second question we posed at the beginning of this section.In § 58 above, we have analyzed the question of the validity of laws with respect to injustice, and we have taken the view that there may be rare, extreme, and unusual situations in which , even if the written constitution does not stipulate the standards that legislative acts must comply with, the courts can also challenge the rationality of a positive law.Such problems are less likely to arise in democracies governed by humanitarian ideals, but they can become acute both under tyranny and under political and social institutions that supersede tyrannical rule.In the latter case, the regime that succeeded the despotism would be compelled to pass judgment on the outrageous acts of brutality committed under the pretext of the positive law of the state during the despotism.In general, we should think that, in appropriate historical circumstances, appeals to fundamental considerations of justice that are contrary to statute law (contra legem) should not be regarded as intrusions on judicial power, since some laws are incompatible with civilized The requirements are so inconsistent that judges are entitled not to regard them as law.
We propose the following hypothetical example as a model of legal provisions that transcend the legal sovereignty of a state or nation: a law that allows a court to crimes; a law orders the extermination or extermination of a religious group or ethnic minority whose beliefs are undesirable; a law allows mobs to lynch people; a law orders the killing of innocent children—just as Herold ( The law enacted by King Herod.The above example would appear in a situation where, as Radbruch puts it, "the disparity between positive law and justice is so intolerable that positive law, being a false law, must be subordinated to justice." It is pointed out that, in all the above examples, it is clear that some persons or groups of people are seriously injured or likely to be seriously injured by the outrageous disregard of the minimum standards of civilization recognized by reasonable people.There is, however, a fundamental difference between the above-mentioned laws and those statute rules which do not have elements of injustice contrary to the highest values of life, chief among them: tax laws which are considered by most to be too high , or laws that alter long-established habits or customs of a people (such as laws desegregating racial or religious segregation).It is held that the principle that wholly unjust laws are void laws cannot be properly applied to the latter classes of laws.
Rationality is man's (limited) ability to understand and deal with reality intellectually.A rational person is able to discern general principles and to grasp some fundamental relationship within things, between people and things, and between people.Rational people have the potential to see the world and judge others in an objective and detached way.His evaluation of facts, people, and events is not based on his own unanalyzed impulses, preconceptions, and prejudices, but on his openness and openness to all the evidence that would lead to a considered judgment. Careful judgment.Nor is he concerned with the consequences for his own material benefit of discerning the truth of things.
The relationship between people and things is often complicated and ambiguous, and people will evaluate them according to different viewpoints, so in most cases, it is impossible for human reason to solve the difficult situations presented by human social life. On the one hand, one and only one ultimate correct answer is found.A rational being will often find that in judging an event or deciding the right course of action to be followed, he is confronted with a variety of methods and possibilities.As in other spheres of collective human life, so do the legislative and judicial processes.Relying on reason alone, legislators or judges are not always able to make a definite and completely convincing choice among two or more methods that can be used to solve a certain problem.In this regard, the views of some representatives of the classical natural law school are also wrong, because they believe that as long as people use their in abstract reasoning ability, they can construct a universally effective and perfect legal system and all its details.
On the other hand, however, we cannot deny that in the implementation of a legal system there are situations where a particular solution to a problem has a compelling and irrefutable force that compels legal decision makers to to accept it.In the above cases the very nature of things (in the terminology of the Roman jurists it was called natura rerum) had imposed a certain result on the legislature and the judiciary.Since we are concerned here with the problems of describing and evaluating judicial source material, we will confine our discussion to the confines of the judicial process.
The natura rerum, which provides the standard of judgment for certain cases, can be divided into the following categories: (1) it may arise from some fixed and necessary natural condition of man; (2) it may arise from some (3) It may be rooted in the basic attributes of a certain human political and social life system; (4) It may be based on people's understanding of the basis of a certain social form Awareness of the basic necessary conditions or prerequisites.We now illustrate the various manifestations of the above-mentioned properties of things as normative forces.
As far as the first category of situations discussed above is concerned, the fact that minors do not have the legal capacity to conclude binding agreements and to initiate proceedings in court without the proper representation of a guardian is undoubtedly based on natural facts .Likewise, the more general rule that mentally ill persons cannot make legally valid promises is established by the psychophysiological inability of such persons to take responsibility for their actions.Roman jurists also traced the right of self-defense to an inherent human orientation toward self-preservation.A United States court concluded from its analysis of the close relationship between parents and children that no court could transfer a child from its natural parents to some other person unless there were exceptionally significant reasons.
We can find an illustration of the second type of situation mentioned above in the procedure of restoration of property in ancient Rome.A strict rule governing suits accepted by marshals requires that the subject matter be presented in court.When the question of the applicability of this rule to immovable property first arose, the natura rerum itself provided a convincing answer to the question.In situations where real property is located many miles from a city, such an option is clearly unavailable to adjudicate on the principle of production of the real property that is the subject of the action, and need not be seriously considered.In other cases, certain legal rules are considered necessary and necessary by the society because of certain natural or climatic conditions in the area concerned.For example, the common law principle that parties on both sides of a river have equal rights to river water resources and use of river water has never been recognized in the arid western states of the United States.Instead, the principle is that the first occupant of a river has the priority of beneficial use of the water.Clearly, in this case, the geographical fact of scarcity of water determines the outcome, since the application of common law principles may well prevent anyone from using water in a socially beneficial manner.As the Utah Supreme Court noted, "If that principle were recognized and applied in this Territory, it would still be a不毛之地。”再者，普通法关于牲畜非法侵入他人土地的责任原则，也遭到了犹他州地区法院的否定，因为这块领土的特征是面积巨大、居民点稀少、土地尚未被圈，而且还与公共土地紧密相邻；如果承认这项普通法原则，“那么实际上就等于剥夺了牲畜主人使用公共土地的权利。”
在第三类情形中，人定制度的基本性质也可能产生被认为是必要的和必然的法律规范。例如，有一规则规定，如果某个法官与当事人一方关系密切，那么他就必须回避听证和审判该案件，而这一规则就是源出于司法职责本身固有性质之中的。就创立这一职责的宗旨而言，它本身就要求以公正无私与不偏不倚作为它正当发挥作用的条件。人类设立政府的一般宗旨与目的，在承认与主权机关所拥有的权力相关的某些规则或原则的方面，也同样是一种决定性因素。由于所有政府的职责都在于保护其所负责管理的社会中的成员，使他们免遭来自内部或外部的严重侵犯，所以人们就认为，政府必须永远有能力履行保护社会并使之免受严重侵害的义务。这一考虑似乎对美国总统所拥有的行政权力的范围有着重要影响。无论是从广义的角度还是从狭义的角度去看待美国总统的权力，我们都应当认为，按其职责所具有的那种性质，美国总统必须能够在前所未有的和未曾预料的紧急状况中采取行动以保护美国人民，直至国会能够召集起来并采取必要的立法措施以应对这种局面。
约翰·洛克（John Locke）坚信政府权力有限说和政治统治民主观；我们可以征引他的权威性论述来支持上述观点。洛克指出：
由于立法者并不能预见所有可能对社会有益的东西并通过法律加以规定之，所以按照普通自然法，操握权力的执法者在国内法没有指出方向的许多情形中有权为社会之利益而运用权力，直至立法机关能按当时情形之需要召集起来对该情形予以规定之……。其实，在某些场合，适当之举乃是法律本身应该让位于执行权，更确切地说是应该让位于这一根本的自然法和政府：即应当尽可能地保护社会所有成员。
洛克在此段文字中援引“普通自然法”，乃是为了支援这样一种观点，即当社会利益危如累卵之时，政府权力的行使是不能出现真空状态的。当然，人们仍有充分的理由坚持认为，这种剩余权力的适用范围应当受到行使这些权力的时机的限制，而且这些权力的行使还要受到所有可适用的宪法限制规定的约束。
“麦卡洛克诉马里兰州”（McCulloch v.Maryland）一案的判决，也可以说部分的是以那些源于事物之性质的相似考虑为基础的。在该判决中，美国最高法院认为，美国联邦政府拥有这种不言而喻的权力，而这些权力则是政府为履行宪法明文授予它的特权所合理必要的权项。出于同样的理由，国际法院也认为，联合国必须被认为拥有那些对于它履行其义务来讲必不可少的权力，尽管联合国宪章对这些权力没有加以明文规定，但是它所承担的义务却必定意味着它拥有这些权力。
最后，在第四类情形中，一些法律规范产生于人们对社会、政治和法律等制度在生成与发展的历史背景和社会环境中具有的某些基本功能特征所进行的思考和观察。例如，在古罗马的家庭结构中，男性家长被视为是家庭成员中惟一能够享有权利和承担义务的人。家庭中的其他成员，其中包括已成年的儿子，都完全受他的控制，而且从象征的意义上来讲，这些家庭成员还被认为是男性家长人格的一部分。根据上述观念，一位著名的罗马法学家保罗（Paul）指出，尽管没有禁止父亲因其儿子偷窃而对他提起诉讼的法律规则，但是事物之性质却对这种诉讼设置了一个不可逾越的障碍，“因为我们不能对那些受我们控制的人起诉，正象他们不能对我们起诉一样。”同样，我们也可以这样认为，教会法制度禁止离婚的规定，直接源于罗马天主教关于婚姻的观念，即婚姻乃是一种具有神圣誓言力量的终生结合，因此这种禁止离婚的规定就不必在教会法的实在规则中予以明文表达。可能有必要指出的是，夫妻终生结合的一次性观念对普通法中的侵权法与财产法的发展也产生过很大的影响。
在“克兰多尔诉内华达州”（Crandall v.Nevada）一案中，美国最高法院在宪法命令没有规定自由迁徙权利时，从一个自由国度的基本条件中推断出了人们享有在本国国境范围内自由迁徙的权利。同样，承认交易自由这个一般性原则——该原则受实在法所规定的某些限制的约束——从逻辑上讲，乃源出于资本主义经济的基本前提，因为资本主义经济的力量是从最大限度地发挥个人在经营私人企业方面的积极性中产生的。在一个正真的封建社会中，主要的政治和经济制度是建立在君主同其诸候间的个人忠诚关系基础之上的；因此，允许诸候自由将土地转让给第三者的做法就显然与这种社会制度的基本条件相背离，因为这种做法的结果有可能使君主面对一个不可信赖的佃农或是他私敌的佃农。一个社会主义的社会则会认为，以反社会的形式行使私人权利是与社会主义意识形态不相符合的，而且在法律疑难案件中，社会主义社会通常会优先考虑集体整体的利益，尔后才会考虑个人的利益。
德国法学家海因里希·德恩伯格（Heinrich Dernburg）曾提出下述见解，“从某种程度上讲，生活关系本身就含有它们自身的标准和它们自身的内在秩序。隐于这种关系中的内在秩序被称之为'事物之性质'。善于思考的法学家在没有实在规范或在规范不完善或模糊不清时肯定会诉诸这一观念。”我们在这里列举的例子足以说明，通过依赖自然理性的命令或从思考和分析人类政治和社会制度的基本性质或功能特征中得出法律结果的方法，法院进一步证实了natura rerum作为法律裁判之合法渊源的可适用性。
我们在前文已经指出，正义观念乃是实施法律的指导原则之
一，而且其意义并不只局限于要求把法律规则和规范性标准公正地适用于所有属于它们调整范围之内的案件。在一起诉讼案中，有时会出现一系列具有奇特特点的事实，而这些事实既不适于按先存规则加以裁判，也无法同早期的已决判例相比较。在这种情形中，正义之考虑会在狭小严格限定的范围内要求背离某条业已确定的规范或对该规范作扩大解释，以达到公正满意地裁判该案件。套用英国中世纪的法学家克里斯多夫·圣·杰曼（Christopher St.Germain）的话来讲，“在某些案件中，有必要摈弃法律中的语词，有必要遵循理性和正义所要求的东西，并为此目的而实现衡平；这即是说，有必要软化和缓解法律的刚性。”当西塞罗（Cicero）在讨论这个问题的时候，他论及了法律越严苛对无辜者伤害就越大的准则（summum ius summa iniuria）；该准则表达了这样一种观点，即刚性适用不受衡平法制约的严格不变的法律规则，往往会导致巨大的灾难和重大的不正义现象。
在讨论有关个别对待异常事实情形的问题时，我们并不关注法院是否会为了完善法律制度或使之与正义相符合而创设新的救济方式或新的辩护种类的问题，也不关注法院是否会将这些新的救济方式或辩护种类扩大适用于它们在一开始并未规定的案件的问题。在这里，我们所感兴趣的乃是去发现法院在遇到由法规或先例所规定的一项实在法规则时，是否会在一个具有异常特性的案件中以在此特殊事实情形中适用该规则会导致对正义的蛮横否定为理由而背离该项实在法规则。
为了对这个问题加以说明，我们拟运用圣·托马斯·阿奎那（St.Thomas Aquinas）所曾举的一个例子和罗马法中的一个例子以为支援，不过作了一些修改。让我们假设，在中世纪的一个城市里有这样一条法规，它规定城门在整个夜间都必须关闭，而违反此规则的人将被判处徒刑。有一天晚上，该城居民由于被敌人追击，所以想找进城的入口。如果看门人为他们打开大门，该看门人是否因该法律不允许对其命令有任何例外而应受处罚呢？或审理该案的法官是否会以立法者如果当时预见到这种意外情形便肯定会规定在这种情形下应当打开大门为理由而承认在该法规的执行中存在着衡平法上的例外呢？为了进一步说明这个问题，让我们再作一个假设，即有一条法律规则规定，不动产销售者有义务将抵押权及其他法律留置权通知买方，而且买方可以因卖方未提供法定信息而要求惩罚性的损害赔偿费。甲方将其财产出售给乙方，并通知乙方存在着某种永久性的留置权。6个月以后，甲方从乙方处买回该财产。乙方却没有明确通知甲方有关留置权的问题，因为他知道甲方毫无疑问地确知这一留置权。于是甲方起诉要求惩罚性的损害赔偿费。那么他是否能够根据上述规则而胜诉，尽管他显然是在滥用该法律的文字意义？
许多法律制度在处理有关以衡平方式纠正刚性法律的问题方面，都发展起了各自的机制。根据罗马共和政体的设定，民众大会可以使某项法律不适用于某一个人，然而这一权力后来却被元老院篡夺了。在执政者时期，这一权力又由元老院转移到了皇帝手中。根据罗马天主教教会法的规则，教皇有权使他人不服从教会所规定的一般法，但是对于某些不可更改的自然法原则却不能享有这种权力。中世纪的英国国王们也享有类似的特许权。根据美国的法律制度，我们允许国会通过“私”法规而赋予某些人以对一般法的豁免权（如对所得税法或移民法令的豁免）。我们还默许我们的陪审员通过做出未经专门法律论证证明的一般性裁决并在某一特殊案件中不适用某一僵化和不适当的实在法的方法来纠正该法的刚性或不适当性，例如，纠正因僵化适用共同过失规则而引起的不公平现象。
当我们在讨论那些在裁判法律争议时可以为法院合法诉诸的法律非正式渊源的时候，我们的首要重点必须放在法官于裁判法律诉讼案时运用衡平原则的权力上面。传统的英美衡平法制度在其初创之时，是被当作一种针对普通法的普遍性与僵化性的亚里士多德式的矫正剂来使用的，后来它渐渐演变成了一种与普通法规则或制定法规则相区别的规则体系；这二者之所以不同，乃是因为衡平法规则有时是以较为灵活的方式加以表述的，然而那种在历史上起过衡平作用的特许形式则在很大程度上丧失了作用。我们并不倾向于赞成我们的法官以在某一特殊案件情形下适用某一法规会导致严重的不正义现象为理由而拒绝适用该法规。另外，就是在今天，高级法院的法官们也往往不愿意将衡平法上的例外情形移植到司法规则中去，尽管他们在这个领域中的自由要大于在制定法领域中的自由。
作为一项未来的政策，重新赋予法官在异常棘手的案件中以有限的权力去实施个别衡平（individual equity），而不管应予适用的法律规则是制定法规则还是司法规范，看来不仅是可行的，而且也是可欲的。我们在将这种权力授予陪审团的同时却拒绝给予法官以这种权力，这显然是不合逻辑的。如果陪审团具有一种隐形的（sub rosa）权力以制止在某一案件中适用恶法，那么我们就没有理由宣称法官在某一合适的情形下不能公开行使这一权力。考虑到下述事实即陪审团在民事案件中的作用在英美法系中似乎正在削弱，而且陪审团在民事案件中将被完全取消的情形也是指日可待，上述论点就变得特别有说服力了。似乎没有什么强硬的理由可以使我们这样认为，即实现公平结果的可能性必须取决于该案件是由法官审理还是由陪审团裁决这样一个偶然性因素。
然而，我们必须坚持认为，如果我们赋予法官以实施个别衡平的权力，那么我们必须要注意的是，这种权力的行使不应达致侵损规范性制度的程度。首先，法官行使这种衡平裁量权（equitable discretion），必须始终受到上诉审查的约束。还应当明确指出的是，法官只能在罕见的情形中行使这种特权，即在适用实在法规则会导致一种被绝大多数有理性的人斥责为完全不能接受和完全不合理的结果的情形中行使这种特权。另外，在法官背离一项制定法规则的情形中，法官还必须能够从研究该法规的背景中得出这种结论，即如果立法者在当时能够预见会发生这种情形，他肯定会对该规则创设一种例外。如果以此方式将该权力视为是一种高度例外的权力，又如果法官完全深信，仅仅是个人不同意某项实在法规则，在任何情形下都不能构成行使这一权利的充分根据，那么承认亚里士多德的epiekeia会对公正执法所带来的危险，就可以降低到最低限度，而且这种最低限度的风险也是行使任何司法权力都会遇到的。
我们必须牢记一种区别。法官欲免除适用一般性规范的案件，对该法官来说，可能是一个独特的和前所未有的案件。然而，独特性可能只寓于这样一种事实之中，即某一相似的案件在过去从未在该法院或其管辖范围内的任何其他法院中出现过。如果这种情形似乎永远不会在未来以这种或相似方式再出现，那么在这种意义上讲，这种案件就不是独特的。可归于独特这一术语之第二种——更为确切的——含义中的案件数量，与第一类案件相比，总是会少些，这当然是相对而言的。
如果一个法官在某一案件中行使不适用制定法规则的衡平权力，而这一案件在过去从未发生过但却有可能在将来再发生，那么他就必须意识到这样一个事实——至少在承认先例效力的法律制度下他必须意识到这样一个事实——即他实际上所做的可能不仅仅是以衡平手段根据案件本身的事实审判一个异常案件，在很大程度上讲，他还可能在制定一种能够调整将来会出现的相同或相似事实情形的新的规范标准。在英国衡平法历史的早期，这种情形常常发生。正如我们在上文业已指出的，当英国的大法官第一次允许强制照约履行合同时，他所依据的是衡平或良心，因为他认为普通法上的损害赔偿救济手段并不能充分补偿原告因被告违约而使他遭受的损害。然而，一当强制照约履行合同被作为一种理所当然的做法而在其他和类似的案件中被准许时，一开始在衡平法上背离普通法规则（将损害赔偿作为惟一的救济方法）的做法就转变成了一种衡平法规则。一个可以表明相同发展过程的现代例证是美国的某些法院拒绝承认长期不动产合同中的罚金条款，因为在这种情形中，销售者可据此得到比他所受损害更大的不合理的好处。随着时间的推移，许多在开始时因主张“抵制法律”而行使自由裁量权的东西或为实现“不据法司法”的东西，后来则构成了一种补充普通法规则的法律规则体系。正是为了对历史上发展起来的英美衡平法制度同上述所论及的不适用制定法规则的衡平法上的权力加以区别，我们才在这儿使用了“个别衡平”这个术语。
在“纳什维尔，GG圣·L.里诉布朗宁”（Nashville，GGst.L.Ry.v.Browning）一案中，美国最高法院表达了这样一种观点，即田纳西州所采纳的系统惯例（按照这种惯例，为了征税之目的，铁路和其他公用事业这类财产须以完全现金价值确定税额，而所有其他种类的财产则以低于现金价值来确定税额）应被视为是该州之法律。尽管这种对不同财产做区别对待的惯例早先不曾被纳入该州的制定法之中，但是上述结论却是由最高法院做出的。法官弗兰克福特（Frankfurter）先生指出，“将'法律'的概念局限于那些能在成文法典中找到的东西并且无视生活所给它做的注释，显然是一种狭隘的法理学观念。各州业已确立的惯例并不能取代宪法上的保障措施，但它却能确立那种可被称之为州法的东西”。因此，该法院在此案中承认，政府官员所采取的业已确立的和运用一贯的惯例，由于是该州“公共政策”的反映，所以可以被视为合法的法律渊源。同样，在“堪萨斯诉美国”（Kansas vUS）一案中，当该法院面临有关合众国的一个州在美国国家没有同意之前是否能对她提出诉讼的问题时，该法院在没有占支配地位的宪法规范或法规的情形下得出结论道，“公共政策”禁止这种诉讼。
在“关于利伯曼”（In re Liberman）一案中，纽约州上诉法院认为，信托协议中所规定的那种条件即如果信托受益人未经授托人同意就缔结婚约那么他将丧失对信托资金的权利，是违反公共政策的。在这里，公共政策的概念又一次在没有占支配地位的先例的支持下起到了裁判案件的独立渊源的作用。在“大三角直杨坦纳公司诉莫伊尔”（Big Cottonwood Ditch Co.v.Moyle）一案中，犹他州最高法院作了如下陈述，“考虑到犹他州是一个干旱州且储水具有头等重要性这个事实，所以我们对于任何可能会使节约用水变得更为困难的论辩都不予赞同，因为防止浪费水一直是本州的公共政策”。
在上述案件中所使用的公共政策（public policy）这一术语，并不是完全联贯一致的。在“纳什维尔”一案中，公共政策等同于州政府官员所遵循的行政或管理惯例；然而在“利伯曼”一案中，法院所设想的公共政策实际上是植根于其赞成婚姻和反对对结婚的无理限制这种文化价值模式之中的。我们在此节所使用的“公共政策”这一术语，主要是指尚未被整合进法律之中的政府政策和惯例，而社会习俗与伦理标准，我们拟在道德信念、社会取向和正义标准等标题下予以讨论。
为了语义清楚起见，还有必要将公共政策同那种可以被称之为法定政策或法律政策的东西区别开来。例如，在冲突法领域中，论者认为，如果某一外国法规的实施会违反法院地的重大公共政策，那么该法院就不应当适用该外国法规。在许多——固然未必是全部——冲突法案件中，所谓公共政策乃是指法律政策，亦即是说，是一种发布于宪法规定、法规或先例中的重要规范性声明，这种规范性声明反映了社会对于何谓社会之善的普遍观点。我们可以从英国法律著述和法院判例中发现这类声明，例如，在法律的各部门法中，惟一与审判宗旨有关的公共政策就是法律政策，而根据公共利益在司法上创制新法律规则的做法，应被认为是英国法制史上已不再存在的事实。这些观点是以狭隘的实证主义为基础的，而这种实证主义认为只有立法机关才有权阐明广义的公共政策观点；然而，上述观点却不能被认为是美国当下司法之趋势的体现。
尽管我们应当认为，在实在法模棱两可或未作规定的情形下，公共政策构成了法官可以适当诉诸的法律的非正式渊源，但是法官对于实施与基本正义标准相冲突的公共政策应当具有否决权。这源于我们在本书中所提出的一般性理论，即正义乃是法律观念本身的基本成分，而由某一政府机构所提出的公共政策则不能与其相提并论。尽管为了实现法律安全这个重要价值，法官必须在正义与实在法规范之间做出许多折衷和调和，但当我们面对的是一种法律非正式渊源——这种非正式渊源就象公共政策、行政政策以及惯例一样在法律渊源等级中只居次要地位——的时候，折衷和调和亦就无甚必要了。所谓公共政策，按我们的理解，主要包括某些政治或社会紧急措施的准则。然而，紧急措施在法律秩序的价值等级序列中表现为一种低于法律安全和正义的价值。
的确，在某些情形下，采取紧急措施的要求会变得极为迫切，所以不论是立法者还是执法者都不能忽视它们。因此，战争、饥荒、内乱、劳力之缺乏或生产制度太落后等情形都可能会要求采取紧急措施甚或采取一些按正义观点可以提出质疑的严厉措施。但是在这种情形下，法律机关应当以执行那些可能对正义造成最小侵损的紧急措施为原则。它们应当仔细权衡处于危急之中的彼此冲突的各种利益，而不应当不经批判的考察便接受最容易且最显而易见的一种解决方法。
根据上述考虑，我们就可以对美国最高法院在“纳什维尔，C.和圣·L·里诉布朗宁”一案时所采取的方法提出质疑。在此案中，尽管美国最高法院将铁路和公用事业这类财产以完全现金价值征税的行政惯例认可为法律，但是该法院对于其区别对待的税收惯例的做法是否符合正义之基本原则的问题却没有做任何探究。尽管该法院也许有相当的理由证明这种区别税制是正当的，但它却在没有追究该行政惯例的基本公平的问题时便接受了该行政惯例。
关于社会道德信念在法律发展过程中所起的作用，我们已在前文中作了讨论。在美国的法律中，如何确定道德信念的问题在下述情形中会变得尤为重要，如在良好的道德品德被作为取得某项权利或特权的先决条件的情形下或在违反公德的行为会导致某种权利或特权丧失的情形下就是如此。正如美国一家地区法院所指出的，“在裁定良好道德品德问题时，法院的个别态度并不是标准。由于这种标准具有公认的缺点与可变性，所以就时间和地点来看，所适用的标准应当是整个社会接受的行为规范。”人们可能会说，尽管法院肯定会小心谨慎，以免用自己的判断去代替社会的判断，但是也会发生例外情形，在这类例外情形中，社会规范根本不具有理性基础，并因此而会受到某家法院的质疑。例如，如果某个法官被说服并相信，一种普遍的信念乃是因错误信息、非真实的宣传或不理智的情感要素而产生的，那么就应当授予他以采取一种与社会准则不一致的态度的权利。
我们并不总是能够轻易地将社会道德模式同那些对实施法律产生影响的社会取向区别开来。如果我们把社会取向看成是民意倾向，而这些民意倾向却不能被视为是已经发展成熟了的完全确定的正义标准或固定的道德信念，那么我们便会发现，这些取向也常常影响着司法机关。在一个著名的案件中，斯托雷法官认为，国际上强烈的反奴隶贸易的倾向，由于可以得到无数规定奴隶贸易为非法的国际宣言和一些在这方面作了相同规定的国内法规的证明，便可以证明在司法上承认那些谴责这种贸易的国际法规则为正当，即使世界上一些主要国家在当时尚未宣布奴隶制度本身为不合法。然而，他对这个问题还是作了些保留，他认为，一个国家的国内法院应当只对那些被证明赞同这种倾向的国家实施这种规则。法院在解释国际协议中的最惠国条款时，都倾向于遵循有关反对差别待遇惯例、主张平等对待所有有关国家这一世界性的贸易趋势。在“伍兹诉兰西特”（Woods v.Lancet）一案中，纽约州上诉法院特别征引了一种赞成将人身伤害责任扩大适用于由疏忽行为造成的胎中伤害的趋势，而且由于这种趋势同正义考虑相符合，所以该法院否弃了早些时候那些否定胎中伤害责任的判例。在“宇宙照相机公司诉NLRB”（Universal Camera Co.vNLRB）一案中，美国最高法院注意到在该诉讼中呈现出了一种从法律诉讼斗智说转向主张理性调查事实真相说的趋势，在这种理性调查事实真相的过程中，法庭认为一切对正在调查的事项有证明作用的东西都具有相关性。法官弗兰克福特先生指出，“法律运动的方向往往是审判特定案件的一种指导”。如果美国最高法院当时在著名的“德雷德·斯科特”（Dred Scott）一案中就意识到全国许多地区都存在的反奴隶制度情感的强大力量，而不采取那种视奴隶制度为神圣不可侵犯的极端观点，那么南北战争就有可能被避免。
我们应当坚持认为，社会取向如果要在裁判法律问题方面起到一种适当尺度的作用，就应当是一种强有力的和占支配地位的趋势。如果这种取向与一种相反的趋势构成均势，又如果这种取向中所反映的社会原则正处于变动和极不确定的状态之中，那么法院就应当谨慎行事，不可轻率地将这种取向提升到一种调整司法诉讼的规则的地位。另外，如在公共政策的情形中一样，法院也可能会认为一种占支配地位的取向与基本的正义观念不相符合。如果法院能够拿出一个强有力的令人信服的情形来支持上述观点，那么它就有理由适用正义准则而不遵循该取向。的确，法院应当充分考虑到人们就何谓基本正义的问题所提出的各种不同见解，而不应当通过固执地墨守那些也许行将末日的正义观念而抵制社会进步。然而，在对公平正当的基本观念同社会取向进行权衡时，应当赋予司法机关以某种自由，因为尽管这些社会取向在某一特定时间可能是极为引人注目的和极为显著的，但它们实际上却有可能只是缺乏坚实理性基础的昙花一现的观点。
我们已在上文讨论了区别法律与社会习惯的一般标准，并得出结论认为：这两种社会控制力量间的分界线是不易确定的，而且那种在历史某一时期并未被认为具有法律性质的惯例，可能会在以后被提升到法律规则的地位。讨论至此，我们有必要考虑在何种条件下才会发生这种从习惯到法律的转变。
约翰·奥斯丁就习惯法问题采取了一种颇为简单的观点。他认为，在立法机关或法官赋予某一习惯惯例以法律效力以前，它应被认为是一种实在的道德规则（a rule of positive morality）。按照这一观点，对一种习惯的习惯性遵守，即使人们在遵守该习惯时坚信它具有法律约束力，也不足以使该习惯转变为法律。只有得到主权者的承认和认可，方能使该习惯具有法律的尊严。当然，这种观点是根据奥斯丁的实在法理论的需要而产生的；按照奥斯丁的实在法理论，法律产生于政治上居优位者的规定，而永远不会产生于被统治者自发接受的规范性标准。历史法学派则提出了相反的见解，即法律乃是整个社会的法律信念与法律实践的主要表现形式。
如果我们根据奥斯丁的观点而假定习惯法乃是由政治立法或司法立法根据先存的习惯而制成的实在法，那么人们就会产生某种疑问，即一种习惯是否可以在由非政府仲裁人所执行的某种仲裁程序中作为裁定权利与责任的基础；在这种情形中，习惯的有效性往往是不需要政府同意的，但人们也可以有不同的看法，即按照某种牵强的政府默认原则，就可以认为它是经由政府同意的。再者，在当事人仅仅希望按照某种习惯性安排而不进行诉讼就知悉他们各自的权利、法律地位和义务的情形中，任何律师都无法真诚地给予这方面的咨询，因为他除了告诉当事人在没有法院权威性宣告的情形下习惯不会产生法律上的权利和义务以外，毫无任何其他作为。又当某一普通法院认可一种先存习惯并裁定某个人因违反该习惯而须对损害负责时，奥斯丁认为，该法院是在创制法律并将它追溯适用于在此案件事实发生时并不为该法律调整的情形。在所有上述三种情形中，相反的结果却往往同现实、正义和便利更相符合。如果对于服从奥斯丁理论所导致的结果不存在某种令人非信不可的必要性，那么我们便可能有充分的理由认为，人们能够为解决习惯法的承认问题确立一种更能令人满意的理论基础。
然而，在解决这一问题时仍存在着一些很棘手的困难，而这些困难主要源于这样一个事实，即某个社会或群体的成员在实践某种习惯时乃是无意识的，亦即是说他们并不是有意要制定法律。由于一些主要的法律制度认为，一种习惯之所以成为法律，并非只是因为它得到了某个社会或群体的成员的遵守，所以我们总是会有某种疑虑，即一种习惯是否只是代表一种社会惯例，一种礼仪规则或某种道德信念的积淀，而不代表一种法律规则。换言之，在立法机关或法院赋予习惯以法律效力以前，习惯是否具有法律实效往往是不确定的。
在罗马法系中，从法律上承认习惯也存在着不确定性，其主要原因乃是一些罗马法系的国家要求在法院将某种习惯当作一种法律规则加以实施以前，这种习惯必须要附有法律意见或必要意见。这一要求意味着，如果社会成员坚信某种习惯不具有法律约束力而且不是实施权利与义务的渊源，那么该习惯便不能被承认为法律规则。那种仅仅源于同情之感或礼仪，或仅仅源于习俗的习惯，是不可能产生法律的。显而易见，在法院确定社会是否在事实上的确相信某种习惯具有法律约束力之前，习惯的性质往往是不确定的。
在普通法系中，围绕着某种习惯在立法承认或司法承认以前是否具有法律强制性这一问题的不确定性，主要是由这样一种假定造成的，即法院有权以某种习惯的不合理性为理由而拒绝赋予该习惯以法律实效。正如纽约州上诉法院所指出的，“合理性乃是某一惯例的有效要件之一，所以法院不能确立一种不合理的或荒谬的习惯去影响当事人的法律权利。”因此，当曼斯菲尔德（Mansfield）勋爵在18世纪从事有关将大陆商法习惯规则整合进英国普通法的工作时，他否弃了那些他认为不合理或不适合其时代或国