Why Precedent in Law (and Elsewhere) Is Not Totally (or Even Substantially) About Analogy

Abstract

Cognitive scientists and others who conduct research on analogical reasoning often claim that the use of precedent in law and elsewhere is an application of reasoning by analogy. In fact, however, law’s principle of precedent, as well as the way in which precedent is used in ordinary argument, is quite different. The typical use of analogy in legal argument, including the use of analogies to earlier decisions, involves the retrieval of a source analog (or exemplar) from multiple candidates in order to help make the best decision now. But the legal principle of precedent requires that a prior decision be treated as binding, even if the current decision maker disagrees with that decision. When the identity between a prior decision and the current question is obvious and inescapable, precedent thus imposes a constraint quite different from the effect of a typical argument by analogy. The importance of drawing this distinction between analogy and precedent is not so much in showing that a common claim in the psychological and cognitive science literature is mistaken, but that making decisions under the constraints of binding precedent is itself an important form of decision deserving to be researched in its own right, but which has been ignored because of the erroneous conflation of constraint by precedent with reasoning by analogy.