What is Legal Doctrine

Legal doctrine is the currency of the law. In many respects, doctrine, or precedent, is the law, at least as it comes from courts. Judicial opinions create the rules or standards that comprise legal doctrine. Yet the nature and effect of legal doctrine has been woefully understudied. Researchers from the legal academy and from political science departments have conducted extensive research on the law, but they have largely ignored each others' efforts.1 Unfortunately, neither has effectively come to grips with the descriptive meaning of legal doctrine. In this Essay, we propound various theories of how legal doctrine may matter and how those theories may be tested. Legal doctrine sets the terms for future resolution of cases in an area. Doctrine may take many forms; it may be fact-dependent, and therefore limited, or sweeping in its breadth. One doctrinal distinction commonly discussed in the law is the distinction between "rules" and "standards."2 Rules are strict requirements that define the answer to a dispute, once the predicate facts are established. A rule is something like "any subsequent and unauthorized use of another's mark constitutes trademark infringement." Standards, by contrast, are more amorphous guides to resolving disputes, often listing a set of factors to be considered and balanced. A standard would be a law that directed "trademark infringement occurs when there is a likelihood of confusion between the senior and junior marks, as determined by weighing the following factors . . . ." Both doctrinal approaches are found in the law, but there is little analysis of why one might prefer a rule or a standard and what the subsequent effects of the two types of doctrine might be.3 It is frequently presumed that standards leave space for more ideological judging, but this claim has never been demonstrated. Legal researchers have extensively dealt with doctrine as a normative matter but have given little attention to the manner in which it actually functions. Social scientists, who have done important descriptive work about how courts actually function, have largely ignored the significance of legal doctrine. Consequently, we are left with a very poor understanding of the most central question about the law's function in society. Fortunately, recent years have seen the beginning of rigorous research into this question. As legal researchers increasingly conduct quantitative empirical research and collaborate with social scientists, we may hope for an efflorescence of this research and greatly enhanced understanding of legal doctrine. This Essay sketches a theoretical outline of how that research might proceed. I. TRADITIONAL LEGAL VIEWS OF DOCTRINE The conventional legal approach to the law is all about doctrine. Legal academics understand that the language of judicial opinions represents the law. The classical form of legal scholarship was doctrinal analysis, in which a researcher examined the content of a legal opinion to evaluate whether it was effectively reasoned or to explore its implications for future cases.4 Doctrinal analysis was grounded in a descriptive premise that reasoned argument from doctrinal premises actually explained judicial decisions. This research was often evaluative and critical. It implied, however, only that courts had erred, such that a persuasive doctrinal analysis could show the judiciary the error of its ways and provoke a new course of legal reasoning. Legal academics, unsurprisingly, have focused on the traditional legal model of judicial decisionmaking based on "reasoned response to reasoned argument."5 Through this process, one obtains "legal reasoning that can generate outcomes in controversial disputes independent of the political or economic ideology of the judge."6 Central to this legal model is the basing of decisions on some neutral legal principles, free from any political or personal contamination. If the law rules, the identity of the judge should not determine the judicial outcome. …