Abstract: Judges on a multimember court might vote in two different ways. In the first, judges behave solipsistically, imagining themselves to be the sole judge on the court, in the style of Ronald Dworkin’s mythical Judge Hercules. On this model, judges base their votes solely on the information contained in the legal sources before them – statutes, regulations, precedents and the like – and the arguments of advocates. In the second model, judges vote interdependently; they take into account not only the legal sources and arguments, but also the information contained in the votes of other judges, based on the same sources and arguments. What does the law say about these two models? May judges take into account the votes of colleagues when deciding how to vote themselves? Should they do so? Are there even conditions under which judges must do so? To date, the law has no general theory about how to approach interdependent voting. Each setting is taken on its own terms, and judges muddle through. The problem is that some judges muddle in one direction, some in another, without any consistent approach, either across judges, or across settings. We argue for a presumption that judges not only may but should consider the votes of other judges as relevant evidence or information, unless special circumstances obtain that make the systemic costs of doing so clearly greater than the benefits. Our view is not absolutist; we do not say that judges should always and everywhere consider the votes of other judges. Under certain conditions, it may be better for decisionmakers not to attempt to consider all available information, and we will attempt to indicate what those conditions might be, in this domain. But we will argue that such conditions should not casually be assumed to exist. Interdependence should be the norm, and solipsism the exception, so that unless judges have good reason to do otherwise they should take into account the information contained in other judges’ votes. Our central case is an extended fugue on Chevron-related examples and variants, but we also consider qualified immunity, new rules in habeas corpus, mandamus, and the rule of lenity.