The article highlights Juan Serapio Lois' work, and the context of the time in which he lived. Research concerning the history of psychology in Chile sets the beginning of psychological science in the country during 1889, when Dr. Jorge Enrique Schneider arrived at the Instituto Pedagógico of Universidad de Chile. However, the progress of historiography has identified Lois as an advanced pioneer, who performed important work influenced by Auguste Comte's positivist thinking. The present study follows the rhizomatic methodology for the history of psychology and seeks to determine the reasons why Lois must be considered a pioneer of Chilean scientific psychology ©2013 by Psykhe ISSN 0717-0297.