The right to trial by jury and the requirement of proof beyond a reasonable doubt are two of the most fundamental commitments of American criminal law. This article asks how the two are related, that is, whether disagreement among jurors implies anything about whether the beyond a reasonable doubt standard has been satisfied: Does the due process requirement of the beyond a reasonable doubt standard also require jury unanimity in criminal cases? Drawing on literature about the epistemological significance of disagreement, this article considers the “equal-weight view” and its implications for the unanimity rule in criminal jury decision-making. The equal-weight view says that, roughly speaking, when people disagree on a topic, each view should be given equal weight. This implies, this article concludes, that the unanimity rule is required as a way of enforcing the beyond a reasonable doubt requirement. This article further concludes, however, that jurors should not always be instructed to apply the equal-weight view in their deliberation. Jurors, when applying crime definitions to particular cases, make determinations about both historical facts and normative issues through moral terms like “reckless,” “unjustifiable,” “depraved,” “cruel,” and “heinous,” which are common in criminal law. This article argues that while the equal-weight view should guide the jurors in determining factual issues, it is not the correct model for moral issues, not only because it would imply that acquittals are appropriate in many cases involving controversial moral questions but also because having the jurors follow it would undermine the basic justification for having the criminal jury as an articulator and enforcer of morality.