Epistemology Listen/ɨˌpɪstɨˈmɒlədʒi/ is the branch of philosophy concerned with the nature and scope (limitations) of knowledge. It addresses the questions: What is knowledge? How is knowledge acquired? To what extent is it possible for a given subject or entity to be known? Much of the debate in this field has focused on analyzing the nature of knowledge and how it relates to connected notions such as truth, belief, and justification.