Endogenous and Dangerous

Empirical studies show that courts frequently cite cases the parties did not during briefing and oral arguments—‘endogenous’ cases. This article shows cognitive rational dangers of endogenous presents an empirical study their use. I contend judges should avoid using in reasoning opinions. article’s first significant contribution is to provide exhaustive treatment American legal literature bases upon which defeasible deductions analogies may be built critical questions or defeaters can weaken bring them down. As far as we know, Aristotle was Westerner formalize logic, about 2,500 years ago. He recognized immediately, however, valid deductive forms he described do take us human affairs. Contemporary law scholars nevertheless talk rule-based if it exists law. But all arguments, even apparently ones, are subject defeat by counterargument—they ‘defeasible.’ a sense more defeasible, thus complex, than deductions, suggests policy arguments still. But what happens when build these around have cited—endogenous cases? Studies suggest so half time. The theory reluctant so, they most with arguments. until now, no has examined how use second cited random sample federal district court opinions, identifying where found used them. It also identifies hierarchy badness among case uses, warning away from dangerous. concludes or, at minimum, permit argue before application. Though opinions studied here were trial courts, principles extend any tribunal uses previous guide its decision-making.