A theoretical reflection on epistemology is presented. The important role of epistemological analysis in research in mathematics education is discussed. I analyze the epistemological evolution as a consequence of the changes in the mathematical culture and demonstrate how the epistemological analysis is tightly linked to the cultural dimension. Then I analyze the connection between epistemology and networking of theories. Different meanings of the word "epistemic" are observed as well as the role of epistemology in the networking of theories.