Which kind of legal order? Logical coherence and praxeological coherence

This article is a development of the idea, proposed by F.A. Hayek, that the order of common law is an order of actions, that is, a coordination of the plans of individuals in a system of exchanges governed by that law. This is in contrast to the idea that legal order is primarily to be found in the logical coherence of the law’s doctrines and concepts. (An important example of the latter approach is the wealth-maximization framework of William Landes and Richard Posner.) The article shows that logical coherence is neither necessary nor sufficient for an order of plans, or “praxeological coherence”. It argues for the classic common law position that the law develops in accordance with the marginal expectations of the relevant parties. To the extent that the law develops in this way, it is possible for the twin goals of the common law to be approximated: relative certainty and adaptation to novel circumstances.