However, the law itself has its own endogenous system of production of rules, which operates on the abstract plane of the configuration of the structure of the relationships between its terms, and whose dynamics depends on the negative feedback process implied by the judicial work itself to clarify the words of the law for each specific case to be decided. Both in codified law systems and in customary law systems, the current positive law is clearly defined. The legal systems in which previous judgments oblige judges are even more rigid than codified systems, since in the latter it is enough for the legislature to enact a new code for the positive law to change. On the contrary, the judges must make a hermeneutical effort to modify the doctrine consecrated in a judicial precedent without this constituting an arbitrary ruling.
However, both in coded and customary legal systems, the law, which is always enunciated in express statements, carries with it the phenomenon of the open texture of language. These are not the cases of ambiguity, vagueness, or obscurity of the letter of the law. These latter cases can be solved by the doctrine, composed of scientific works that investigate the debates between the members of the legislative power at the moment of sanctioning the norm whose text carries such problems, or resorting to the normative antecedents of which the current law took its vocabulary.
However, vagueness, obscurity, and ambiguity in the words of the law configure linguistic problems with legal relevance, but not legal ones in themselves. What really matters to study are the cases of open texture of the language of the law, since it is through these cases that the law evolves.
In cases of open texture of language, the anomaly occurs in the universe of events to which the language refers. An obvious example: a constitution written in the 19th century can establish that the President is the Commander-in-Chief of land and sea forces. It would not be necessary to reform its text to incorporate the air force – or even weapons built to act outside Earth’s orbit.
However, the dynamics of legal traffic are mostly made up of less obvious cases in which the open texture of language forces judges to establish the words of the law for the specific case, resorting to a hermeneutic interpretation of the law for which “common sense” is not enough. In customary law these hard cases are those that generate a new precedent that often define what is inside and what is outside the “good legal sense.” The authors disagree among themselves on how to characterize this aspect of judicial work. However, the remarkable thing is that these “difficult cases” generated by the phenomenon of the open texture of the language are what make the law respond autonomously to changes in the conditions of the environment that the same right has as a regular task.
Indeed, Friedrich Hayek states in Law, Legislation and Liberty an attempt to separate law and politics based on the evolution of law according to a process of natural selection of norms. While it expressly recognizes that a legal system can be sanctioned in its entirety by the legislator, it also highlights the ability of legal systems to make an immanent critique of themselves, through the judicial system.
Although Hayek does not analyse the phenomenon of the open texture of language in his work, it does characterize law as a structure of norms that continually readjust to changes in circumstances following a negative feedback process, through successive judicial decisions. In Hayek’s own words, what establishes a legal order is a set of expectations about the behaviour of congeners that will be considered or not according to law. For example, if a party fails to meet its contractual obligations, it can expect the other party to refuse to comply with them and that, if sued, the latter will be supported by the courts. This expectation also works as an incentive to fulfil contracts and reduce litigation.
On the other hand, another feature of legal systems -particularly modern ones- that Hayek highlights is the definition of a range of expectations that will be systematically thwarted. This is what determines a structure for human action and implies the consecration of the principle of closure: everything that is not expressly prohibited is allowed. This allows individuals to form their life plans with the expectation that they will be fulfilled and with the ability to anticipate the behaviour of their peers, since they will be under the same incentive structure. The latter leads to a third characteristic of modern legal systems, which allows them to function as self-regulated systems: the principle of isonomy or of the same law for all. The incentive structure determined by the range of expectations that will be systematically frustrated, in a system that results from the same application for each individual, allows the definition of individual spheres of autonomy, within which each individual has free discretion, but when entering into collision with each other, each one will be able to infer what expectations they can have regarding a possible judicial ruling.
The reverse of this system is the “Administrative State,” by Carl Schmitt, in which only that which is expressly authorized by a decision based on expediency, and the status system of the Ancient Regime, is permitted, that each group had a private legal system or privilege-strictly speaking, our current modern system of rights consists in the extension to all human beings of the liberties or privileges that the nobles had wrested from the kings at the time. Therefore, it is a great risk that the number of regulations is such that the rule becomes that only what is specially expressly regulated can be done, depending on the dynamics of the change of the decision of the authority taken in administrative files, and that such is the segmentation of regulations according to pressure groups and interest groups, that they return to a system of privileges instead of equality before the law.
It is not difficult to find numerous current examples: the public transport system could reach levels of regulation such that it could practically be said that only such activity can be carried out with the express authorization of the public authority to that effect. The alternative is not the absence of regulation, on the contrary, the alternative is the modern State of Law: a set of positive norms, dictated by the competent authority and formulated in general terms. These rules that regulate public transport do not have an abstract content, but rather a concrete one: the set of objectives expressly set by public policy. While the rules of private law have an abstract content, that is, they lack a specific purpose, the rules of public law not only have a specific and specific purpose, but that such purpose must be expressly declared, in such a way that justice they can evaluate whether the willing means disposed by the public authority are related and proportional to the purpose of the rule of public law and, in turn, the citizens consider whether such ends are worth pursuing.
To continue with the exemplification of public transport of passengers and merchandise: there is a sphere that corresponds exclusively to private law. This refers to the rules that attribute legal responsibility between the transporter and the transported: the obligation of the transported to pay the ticket or the freight, the obligation of the transporter to transfer the people and goods without them suffering damages. In this sphere there is no concrete purpose of the norm. It only limits itself to stating the set of expectations that the parties can count on, regardless of who they are specifically and what the specific purpose of the transport is.
Correlatively, the regulation of public transport, which belongs to the orbit of public law, does have certain specific purposes. For example, take care of public safety and ensure an efficient distribution of the cost of accidents. For this purpose, it may provide that public transport companies register, periodically review the status of their units, which must meet certain minimum standards, and establish the obligation to contract civil liability insurance. Anyone who complies with these provisions, for example, could devote himself to the activity of public transport, passengers or merchandise. How many and who will be the transporters is something that the public transport regime should not compete with. The number of carriers will be fixed by the price system. Nevertheless, to the control of public transport must concern that the units that circulate are in good condition, that their drivers are suitable and have an insurance that covers their civil liability, so that the transported does not have to face the cost of accidents before an eventual bankruptcy of the carrier. On the other hand, the system of private law, in a parallel and autonomous way, distributes the responsibilities between the parties, without addressing who is each one.