This chapter is organized into three interrelated sections: (1) “Qualitative Epistemology: The Context of Its Emergence in Psychology, Philosophy, and Social Sciences” traces the emergence of qualitative epistemology amid critiques of positivism in psychology and the social sciences. It highlights how early qualitative research lacked epistemological depth, often misappropriating phenomenology and hermeneutics. Drawing on figures like Tamara Dembo, Kurt Lewin, and Gordon Allport, it emphasizes the need for a theoretical foundation to support research on subjectivity and human complexity. (2) “Advances and Current Challenges of Qualitative Epistemology” presents key conceptual developments over the past two decades, including the articulation of subjectivity as a theoretical object and the consolidation of subjective sense and subjective configuration as core categories. This section also discusses unresolved tensions related to theory construction, methodology, and the integration of social and individual dimensions. (3) “Constructive-Interpretative Methodology: Research as Theoretical Production” outlines the methodological implications of this epistemological perspective, emphasizing the active and creative role of the researcher in producing knowledge through communicative processes. This chapter defends the idea that research in psychology is not limited to data collection but is, above all, a theoretical process that constructs intelligibility about complex subjective phenomena.