Abstract

What does the law demand when it requires citizens to conform to standards of reasonableness? I propose and defend the view that the law should demand that citizens conform their behavior to some actual conduct in society. I contrast this idea against what might be called the ``empty vessel'' view of reasonableness, where the standard is understood to function like an empty vessel in the law, allowing courts to use various norms and moral judgments to determine what seems reasonable in the circumstances. The empty vessel account is the more common approach for understanding reasonableness, but it leaves obscure whether and how assessments about appropriate conduct connect with facts about citizens' actual conduct. I argue for a ``binocular'' view that focuses our attention on actual practices and thereby establishes how these standards provide a stable guide to conduct and support the rule of law.