The rule of law is the principle that society must be governed by rules that apply, impartially and equally, to all people. The rule of law principle includes “equality before the law,” meaning all people within a polity are governed by the same rules, regardless of their personal characteristics, such as race, socioeconomic class, gender, religion, and sexual orientation. The rule of law also serves as a constraint on state power. In contrast to the “rule of men,” in which particular people who hold state power determine when and where specific rules apply, and whether and to what extent they are enforced, the rule of law is aimed at ensuring that all people are accountable and subject to the same rules and sanctions. The rule of law principle is an essential ingredient in the recipe for a peaceful society, as a society in which laws are enforced arbitrarily and unequally is a society that is prone to conflict. If, for example, police impose greater restrictions or unfairly treat a particular group within society, peace is much less likely to prevail in that context. Importantly, the classical liberal defense of the rule of law does not imply that all laws that currently exist are just. In fact, because the rule of law requires equality before the law, it has been a cornerstone principle of many social movements that have overturned discriminatory laws and procedures.