In this article the concepts of epistemological pole I (close to the theoretical frameworks of the researcher) and epistemological pole II (close to the participants perspective from an educational reality) are proposed and illustrated. It is argued that the constant and permanent transit between both poles, as well as the implementation of the epistemological vigilance mechanism enable the development of theoretical knowledge in qualitative research. The article concludes by paying particular attention to the use of theory during the various stages of the research process and the ways in which initial theories can be discarded or extended.