This chapter presents a philosophical framework to help understand the essence oflearning contexts. It starts with a brief historical account of the emergence andevolution of the problems of context in learning, and of their increased relevanceas learning activities migrate to the online world. It then presents a simple modelfor a learning event—involving learner, content, and context—from which it ana-lyzes the answers to three key philosophical questions that discriminate betweenthe positivist and the constructivist worldviews. These answers are expressed inthe form of four foundational hypotheses or principles for each worldview, whichhelp analyze the resulting two radically different interpretations of learning con-texts. The implications of these distinctions on the management of learning con-texts, on the perception of the duality between content and context, and on theapproaches to the design of learning contexts are then analyzed.