The branch of philosophy that studies the nature of knowledge, its extent and validity. An epistemological question might be "How can we really know that . . . ?"(pr. ə-PISS-tə-MAH-lə-jee)Also see appreciate, art criticism, art history, cognitive, critique, discover, empiricism, genius, gestalt, interdisciplinary, liberal arts, memory, metaphysics, mind, ontology, perception, phenomenology, science and art, sense, and teleology.