The philosopher Hannah Arendt once observed that it was arbitrariness, not necessarily severity, that distinguished totalitarian from law-abiding states. Stalin may have had his Gulags, Hitler his concentration camps, but the key to understanding the exercise of totalitarian power there and elsewhere lay in its capricious, unpredictable application, not its harshness. The operation of law is public, regular, knowable in advance. The eruption of the totalitarian impulse inserts a vertiginousness element of whim. That’s part of what makes it terrifying. In a free society governed by the rule of law, people know where they stand. In the normal course of affairs, most people will never directly experience the coercive power of the state. They are not subjected to harassment at the arbitrary direction of state officials. With the erosion of the habits of liberty, however, everything changes. Now the state tends to regard the people first of all not as its raison d’être but as a potential threat. The result is a sharp contraction of that latitude that free societies allow their citizens.