This paper explores the relationship between epistemology, sociology, and learning and teaching in physics based on an examination of literature from research in science studies, history and philosophy of science, and physics pedagogic research. It reveals a mismatch between the positivist epistemological foundation which seems to underpin the teaching of physics at the undergraduate level and the tentative nature of knowledge and the primarily social-constructivist process of knowledge creation which characterise the practices of professional physicists. Attention is drawn to the consequences of neglecting this mismatch, which is detrimental to students' understanding of the nature of the discipline, their conceptual development, and the acquisition of skills essential not only for a scientific career but also for students' development as individuals and citizens. The paper argues for the explicit contemplation of disciplinary epistemology in physics teaching and in pedagogic research to improve student learning and for the avoidance of the dangers of epistemological essentialism.