The present study aims to compare, from the conception of the public, the role of the public library in Colombia based on its praxical relationship, in order to reflect on the institution and the duty of the public librarian, therefore the proposed methodological design consists of three phases: the articulation of a theoretical base, the comparison of five different aspects and the reflection of the phenomenon of study. The study is carried out through the confrontation and analysis of three types of information sources: theoretical, documentary and practical. The state of the praxical relationship of the public or public sphere in the country's public libraries is described in relation to the political dimension they are called to assume, so that the information unit seems to be at a midpoint between being political and apolitical. Regarding the objectives, it is concluded that the common elements among the three authors (Arendt, Habermas and Mouffe) of what the public or public sphere should be are freedom, equality and diversity; that one of the priority tasks of Colombian public libraries is the construction of peace and reconciliation based on the coexistence in the public space and that in some elements the practice coincides with the theory, but in others it diverges and this responds to the conditions of our context.