On universal relevance in legal reasoning

The purpose of this essay is to defend a claim that a certain consideration, which I call unworkability, is universally and necessarily relevant to legal reasoning. By that I mean that it is a consideration that must carry legal weight in the justification of some judicial decisions in every legal system in which (1) all disputed matters of law can be adjudicated, and (2) all judicial decisions are to be legally justified. Unworkability's necessary relevance has important implications for a theory of relevance presented by Rolf Sartorius. On this theory, nearly all considerations that are relevant to a judicial decision are supplied by legal principles embedded in the legal rules and decisions, or by extralegal principles dependent, in some way, on the legal principles. (The exceptions to the embedding thesis that Sartorius would, no doubt, recognize are elaborated in the text but can be set aside here.) But there are possible legal systems which do not contain an embedded legal principle concerning unworkability; and nonetheless, unworkability is relevant to judicial reasoning in those systems. Hence, a theory of relevance that relies on principles embedded in the content of rules is too simplistic. Some substantive considerations are relevant for other reasons.