… is from pages 868-869 of Mario Rizzo’s superb Winter 1985 Cato Journal article “Rules versus Cost-Benefit Analysis in the Common Law” (link added):
Hayek’s fundamental model of the common law is one of purely private rule creation. The law and the courts are not creations of the sovereign but rather are evolved institutions within which all individuals, including the sovereign, must operate. The common law antedates legislation, and it draws on preexisting implicit societal rules or customs, as well as on previous judicial decisions (Hayek 1973, p. 72). It is by deference to this preexisting opinion that the common law judge can lay claim to authority and legitimacy. People respect his judgments because, in part, they see in those judgments the crystallization of commonly held moral views.
The legitimacy of the law is also enhanced by the abstract character of the rules that the judges draw upon and that is manifest in their opinions.
DBx: Appreciation for the spontaneous and abstract character of the common law has always been rare, and it is getting even rarer. The counsel to follow abstract rules that are the result of human action but not of human design appears to the typical intellectual to be primitive. Far more sophisticated and “progressive” (it is believed) is our deferring to the conscious and discretionary commands of that particular group of human beings who have been elected to exercise power. And yet as Hayek (and a few others, such as A.V. Dicey, James Coolidge Carter, and Bruno Leoni) taught – as as Mario Rizzo elaborates – one of the many great advantages of governance by the abstract common law is that governs with far more detailed and nuanced knowledge than can possibly be used to inform legislative and administrative dictates.
To state the point differently, relying for governance upon abstract, evolving common-law rules is to rely upon a far more accurate and complete method of the weighing of costs and benefits of alternative courses of actions and social arrangements than is available when “cost-benefit” analyses are carried out by politicians, bureaucrats, or econometricians.