Objective: Make visible the traces of philosophical positivism in Library Science and Information Science Design/Methodology/Approach: Through documentary research, the distinctive elements of the positivist philosophical discourse were reviewed and thus show the incidence of this conception in the construction and development of Library Science and Information Science. Results/Discussion: The text analyzes the incidence of positivist thought in the identification of Library Science as a scientific discipline, whose frameworks were configured according to the canons of that philosophical conception. In the same way, the degree of influence of this current was defined in the conceptual and theoretical architecture of the original Information Science, visible in the foundation that tried to be the foundation of the new field of study, based on the Mathematical Theories of Communication. Conclusions: Positivism, as a philosophy shaped throughout modernity, turns science into the only possible knowledge and its method as the only valid one. Under these principles, natural sciences became the model referent for any assessment of reality and thought. Consequently, these positions marked the guidelines of the first theoretical and conceptual attempts of Library Science and Information Science, which were shown as "scientific fields", precisely, from a positivist perspective. Originality/Value: This study is characterized by an approach to the presence of positivist philosophy in the original foundations of Library Science and Information Science, as well as its interrelation with the historical scenarios in which these processes were developed.
