Law and the Epistemology of Disagreements

This Article identifies a discrepancy between law and epistemology and proposes a way to fix it. Our legal system relies on decisions of multimember tribunals, which include juries, state and federal appellate courts, and supreme courts. Members of those tribunals often disagree with each other on matters of fact. The system settles such disagreement by applying head-counting rules: the unanimity or supermajority requirement for jury verdicts and the majority rule for judges’ decisions. Under these rules, jurors can return an agreed-upon verdict even when their reasons for supporting the verdict are inconsistent with one another. Similarly, judges are authorized to deliver any decision so long as it is supported by a majority of the panel. Disagreements among judges and jurors are consequently ironed out instead of being accounted for as a factor that reduces the reliability of the final decision. By adopting these rules, our legal system allows jurors to convict the defendant when six of them believe the incriminating account provided by one witness, while rejecting as non-credible the testimony of another prosecution witness, and the remaining six jurors form a diametrically opposite view of the two witnesses’ credibility. Moreover, the system authorizes appellate courts to determine by a narrow 2-1 majority that a violation of the accused’s constitutional trial right was “harmless beyond a reasonable doubt.” Likewise, it accords the status of an unreservedly binding precedent to a 5–4 decision of the United States Supreme Court that determines the meaning of a statutory or constitutional provision. These rules are fundamentally incompatible with the epistemological principles of rational fact-finding. The epistemology of disagreement maintains that when a person makes a factual finding and then realizes that an equally informed, competent, and honest individual—an “epistemic peer”—arrived at a different conclusion, based on the same information, she ought to scale down her level of confidence in her own opinion. A peer’s disagreement is evidence writ large that a person cannot rationally ignore or discount. Rather, it must be given weight and cause one to revisit her original opinion. This epistemological principle has far-reaching implications for the law. For example, a guilty verdict rendered by a jury cannot be considered unanimous when the underlying reasons contradict each other; a dissent by a single appellate judge should preclude a guilty sentence under the “beyond a reasonable doubt” standard; and a precedent laid down by a narrow majority of the Supreme Court should remain open to reconsideration

Constitutional Evidence Law

This Article identifies the causes and consequences of a puzzling asymmetry in constitutional law. Of the three facets of adjudicative factfinding-evidence, procedure, and rules of decision- only two are constitutionalized. Constitutional law regulates procedural and decisional rules, but not whether the evidence that factfinders use is adequate. Constitutional law regulates procedure through a set of rules that determine a person\u27s power to control the trial by adducing evidence in support of her case and by examining the evidence of her adversary. Constitutional law regulates decisionmaking by setting probability requirements for findings of fact-standards of proof-and by allocating the burdens of proof among the prosecution, plaintiffs, and defendants. Constitutional law, however, does not control adequacy of the evidence upon which factfinders determine the probability of contested allegations and apply the burdens of proof. This is so because the Supreme Court interprets the Due Process Clause, as related to evidence, very narrowly. Under this interpretation, any evidence is constitutionally adequate when its use is not fundamentally unfair. Moreover, fundamental unfairness occurs only in extreme cases such as those which exhibit a serious prosecutorial misuse of the trial process. Examples include when the government knowingly procures the defendant\u27s conviction by false evidence or by evidence from which factfinders can draw no rational inferences. Anything less is not fundamentally unfair. As a result, virtually any rule that controls evidential admissibility and identifies evidence that does or does not require corroboration is constitutional. The fundamental unfairness criterion practically exempts evidential adequacy from constitutional scrutiny

Are People Probabilistically Challenged?

Daniel Kahneman\u27s recent book, Thinking, Fast and Slow, is a must-read for any scholar or policymaker interested in behavioral economics. Behavioral economics is a young, but already well-established, discipline that pervasively affects law and legal theory. Kahneman, a 2002 Nobel Laureate, is the discipline\u27s founding father. His pioneering work with Amos Tversky and others challenges the core economic concept of expected utility, which serves to determine the value of people\u27s prospects. Under mainstream economic theory, the value of a person\u27s prospect equals the prospect\u27s utility upon materialization (U) multiplied by the probability of the prospect materializing (P). When the prospect is advantageous, its utility is a positive sum that augments the person\u27s well-being. When the prospect is disadvantageous, its utility is a negative sum (a disutility) that decreases the person\u27s well-being. Under both scenarios, the full amount of the person\u27s utility or disutility is discounted by the prospect\u27s probability of not materializing. Economic theory holds that the expected-utility formula, P • U, ought to determine a rational person\u27s choice among available courses of action. The action yielding the highest expected utility is the one that the person ought rationally to prefer over the alternatives