When groups of people are represented in classification systems, potential exists for them to be structurally or linguistically subordinated, erased or otherwise misrepresented (Olson & Schlegl, 2001). As Bowker & Star (1999) have shown, the real-world application of classification to people can have legal, economic, medical, social, and educational consequences. The purpose of this research is to contribute to knowledge organization by showing how the epistemological stance underlying specific classificatory discourses interactively participates in the formation of concepts. The medical and legal discourses in three timeframes are examined using Foucauldian genealogical discourse analysis to investigate how their depictions of gender and epistemic foundations correspond and interplay with conceptualizations of similar concepts in four editions of the Dewey Decimal Classification. As knowledge organization research seeks solutions to manage the paradigm change from assumptions of universal knowledge to instability of knowledge, recognition of epistemological underpinnings of classification systems is necessary to understand the very real consequences of corresponding classifications of gender.