This paper intends to present and discuss Antonio Negri s theoretical perspective about the constitution of an absolute democracy by constituent power of the multitude (including elaborations born in his joint work with Michael Hardt). For this purpose, the firtst stage will deal with the main philosophical bases of Negri reflection on the topic, here identified in the writings of Niccolò Machiavelli, Baruch Spinoza and Karl Marx. Through these authors, Negri performs a rescue of a _ emancipatory modernity a quite different of the hegemonic modernity - whose design has been argued through the use of representation and the creation of transcendent figures as sovereignty, people and nation - starting from the verification of the possibility to build another form of democracy, immanent and absolute. The second stage will be dedicated to reflection on the recovery of the multitude category, held by Negri, from his reflections on Spinoza as an appropriate and powerful subject to the constitution of the democratic project in postmodernity, at which the transformations in world of work are considered so deep that require a new conception of a revolutionary subject. On the third stage, will then be addresses the absolute democracy conceived by Negri, referred to in this paper as the common democracy. Here, the common is a concept key to understanding the Negri s project, reason why this paper devotes on this idea before connect multitude subject and constitutional project of democracy. Finally, the conclusions will be presented as contributions to the discussion proposed in this paper.