At the beginning...

For Hayek, the law is logically and chronologically previous to the government. That is the meaning of the rule of law: a political order founded on the law. Since the political powers receive their legitimacy from the law, the latter is exogenous to the political subsystem. That is why Hayek regards the law as a spontaneous phenomenon. This is not a description of the political reality, but a theory on a political system based on the rule of law which the social scientist can derive normative statements from.

Impossibility Theorem

It is amazing to reread “The Road to Serfdom” (1944) and to recall the paper “A Difficulty in the Concept of Social Welfare” (1950) by Kenneth J. Arrow. Specifically, Chapters 5 and 6 of Hayek’s book seem to be a philosophical statement about the consequences of Arrow’s impossibility theorem. Nonetheless, being both works close in time, the complexity of the ideas contained in them prevents us from suspecting any mutual influence, and we must conclude that the parallelism is mostly due to the zeitgeist.

Spontaneity

Spontaneity, being understood as the automatic response of the social order to a change in the environment, is closely related to the concept of negative liberty, for coercion implies an arbitrary command or a lack of information. Since the individual is enabled to infer the spontaneous changes given in a social order from the knowledge of a fragment of it, he can adjust his plans to his own expectancies, not being coerced his will in such cases. This consideration is a bridge to be built between “The Constitution of Liberty” and “Law, Legislation and Liberty”.-

Spontaneous responses to stimuli

What is spontaneous is not the historical origin of an order. Spontaneity is an attribute concerning the type of response of a given order to the changes in its environment. When the change in the disposition of the elements of an order is generated in response to changes in the input of data from the environment by an authority that seeks to obtain a certain effect in that environment, the said order is a created one. A spontaneous order changes the disposition of its elements in response to the stimuli from the environment following not any purpose of any conscious authority, but a pattern built as a negative feedback system. This pattern of response to the input of data from the environment may either come from tradition or be created by a legislator; it may either lack of a historical beginning or have one. What is important is that that pattern provides the order with a mechanism of automatic adjustment to the changes in the given data. In this sense, spontaneity does not mean absence of historical origin but of a purposive source of change.

Naturalistic Fallacy

To distinguish between “spontaneous order” regarded as “Great Society” and “spontaneous order” as “any blind self-generated mechanism evolving in accordance with the changes in the environment” becomes essential when it is necessary to avoid the naturalistic fallacy. The “Great Society” is a spontaneous order provided with several sub-systems which behave as spontaneous orders in themselves, such as the law, morals, language, monetary systems and so on. The present legal system of a given society, although spontaneously evolved, is not necessarily the only possible spontaneous legal system to rule that society.

The Law and the Social Order

That the law follows the evolution pattern of a spontaneous order –like the language or the monetary system also do- does not imply that the rules prevailing in any society -meant as a spontaneous order as well- have to be regarded as norms worth of being obeyed just because they emerge from the spontaneous social order. As we had already said, whether a norm acts as a negative or a positive feedback system, giving society a stabilization devise or not, is subject to being empirically proved. Once that problem is solved, we have to face with the question of if the stable order that that norm contribute to is also in accordance with our values, such as the importance of the individual liberty or of the equality before the law.

Stability

Since rational agents are not fully aware of the rules which govern human action, no social institution can provide the spontaneous order with a complete stability. Moreover, the aptitude for providing stability for any social order is not a necessary attribute for every set of rules that compound an institution. Whether a particular social institution plays a role of a negative feedback system in the social order or not is a statement subject to empirical investigation.