Sociologists of policing and collective protest have made a plea for eradicating from police literature and training programmes which aim to provide guidelines for crowd management any references to classical crowd theory where crowds are depicted as irrational entities. Instead, these scholars suggest, rational conceptions of crowds should inform contemporary crowd management. This article questions this plea on two grounds. First, it demonstrates that there is no unidirectional connection between sociological crowd theory (whatever its content) and practical strategies for governing crowds. The tactical polyvalence of crowd theory is illustrated by showing how the irrational conception of crowds has given rise to very different strategies for the management of crowds (urban reform programmes in the Progressive Era and Hitler’s mobilization strategies, respectively). Second, the article argues that, in spite of its current scholarly popularity, there is no guarantee that the call for a practical employment of the rational notion of crowds will necessarily be successful. This is demonstrated by stressing, on the one hand, that irrational notions of crowds continue to thrive, thereby rendering a turn towards rational approaches difficult, and, on the other hand, that the rational approaches in their ignorance of collective emotional arousal present an inadequate picture of crowds and consequently have limited scope as guidelines for crowd management strategies.