|Luhmann applied the term positive law to law determined by legislation and which gains its
validity through the fact that it can be changed. The most Important property of this kind of law
is that it results in a greater amount of freedom because rejected laws are still available for the
future to overcome problems that were not expected at the time of legislation.
Traditional or natural law, on the other hand, maintains Its validity through tradition which cannot be changed, only Interpreted.
We must return to Luhmann's concept that disappointment in the case of cognitive expectations results in learning. The result of this Is that in the case of cognitive disappointment we are likely to modify either our understanding of the expectation, or the expectation itself Disappointment of normative expectations, on the other hand, results In a refusal to learn. This is the reason why Luhmann calls norms "Counter factually Stabilized Behavior Expectations." If laws are normative expectations selectively chosen through legal Institutions containing their own rules for change, that Is, if such laws are valid because they remain In spite of the fact that they are alterable, then therein must lie the third requirement for an evolutionary system, that is a mechanism for fixing the process. To understand how this mechanism works this we must leave Luhmann because his tendency to reify social systems tends to screen the role that Individuals play in this process. Because it deals with norms that are counter factually stabilized, that Is that have been chosen out of a variety of equally valid competing possibilities, the validity of a law Is never questioned. There may be questions, even very difficult ones, concerning the application of a law to a particular case, but once the problem of application is solved the invocation of the law is automatic. At the same time, disappointments of expectations emerging from the invocation of laws under difficult cases leads to incongruencies in the emotional feeling people have for laws and to the strengthening of those forces that exist within the society which pressure for legislative change. If most members of a society feel a personal responsibility for the existence of the laws of their society then and only then will the legal system respond to Incongruencies which develop from the Interaction between the law and the people subject to it. Congruency of norm evaluations is a communications media. As such it forms the communication between members of a society which emerge into a parallel neural network.
The emergence of a stable legal system can be seen as the development of stable Interactions at the Interface between this parallel neural network of norm communication and the serial change of successive interactions between people and the law. The action of members of a social system reflecting on and evaluating both their conception of the system and their role in it and then choosing activities from among the available variety those which augment their own personal evaluation is a source of gradual serial change. The communications media of congruency, being a parallel network linking many Individuals, is the mechanism which causes legal structures to change abruptly and periodically. Self-reflexivity goes on continuously affecting the threshold levels of Individuals. It is only when the communication of congruency, which is a measure of public consensus, reaches a point where the threshold levels of many people are surpassed by inputs from third parties that the pressure for sudden and dramatic changes in institutions such as law takes place.