Two questions are raised about Hannah Arendt's theory of the public (publicness). First, could "action" be to perform with violence boundlessly and unpredictably? Second, how is the public realm as the common world that "gathers us together and yet prevents our falling over each other" constituted? To address these problems, this paper aims to clarify the constitution of common world and reinterpret her theory of the public. The main subject is to take up her concept of "power" and "promise" in order to clarify the constitution of common world. It is constituted through both avoiding violence of "action" by "promise" and keeping "power". We interpret this trait on common world as the "limits" to violence, and read Arendt's actual warning to "action" that leads to extreme violence.