Under Joseph Raz’s service conception, authority exists because, by binding themselves to follow the authority’s directives, subjects better comply with their reasons for action than they would if they acted on their own judgment concerning those reasons. Sometimes, subjects must interpret an authority’s directive to determine its preclusive scope. In such cases, they should choose the interpretation that best fosters the authority’s service. The result can be the recognition of an exception for emergencies. But such exceptions should be rare. One important reason is that a candidate authority will often have meta-authority: authority about the existence and scope of its own authority. Authorities can themselves be subject to higher-order authority—such as the authority of a constitution. When the constitution’s preemptive scope must be interpreted, authorities should interpret it in a manner that fosters its service for them. The result can be the recognition of an exception for emergencies. But here too, such exceptions should be rare. One reason is that the constitution likely has meta-authority concerning its higher-order authority. A second reason is that officials generally have consented to abide by the constitution. A third is that deviation from the constitution can undermine rule-of-law values.