The huge, diffuse, and uncertain threat brought about by the Covid-19 epidemic has blurred familiar and trusted relationships and the boundaries of public life. Under such circumstances, what people need most is to uncover the “enemy” and regain certainty in interpersonal relations and the public sphere. Before the popularization of accurate and efficient scientific detection methods, people used simple labeling methods to tell concepts apart. Labeling epidemic areas protects the status quo by demarcating cleanliness from pollution, but in finding the enemy, doing so may cause accidental injury to the innocent. Labeling masks allows distinctions in the crowd so that group boundaries and senses of belonging can be found in chaos. However, such labeling may lead to the creation of enemies. The fundamental goal of these methods is self-protection. Nevertheless, in addition to such considerations, individuals have a wider moral obligation to others and to public life. Only by choosing to adhere to our moral obligations under the enormous pressure of a survival crisis can we find true hope to defeat the epidemic. Contemporary public life is a symbiotic community that is closely related, in close communication, and mutually enmeshed. Such a community is very fragile, and it can easily slip into divisiveness and become isolated under huge security pressures. The Covid-19 epidemic is not only a serious challenge, but also an important exercise. We need to learn enough to prepare for greater crisis that may arise in the future.