This thesis analyzes the way in which Jorge Eliécer Gaitán, through his life experiences and his personal connections, constructed the knowledge that allowed him to interprets and intervenes his context between 1920 and 1946. This text is a contribution to the history of social sciences beyond the institutionalization in Colombia. The first chapter explores the young conception that Gaitán had about the society based on marxism, the german Darwinism, and the sociological tradition. Finally, the last chapter shows the connections between this social concept and his projects of social development constructed during his labor in public positions.