Science was conceived as something absolute by the Positivists; they thus failed to see that it is basically a human activity and that no human phenomenon can be absolute. The discussion in this monograph takes its departure from this point and investigates the epistemological foundations of science. It argues that one such foundation is the worldview of the scientist which reflects his physical-social environment. If this is the case, then it becomes clear why there can be a certain scientific activity that can be identified as Islamic. This is the fundamental theoretical ground upon which Islamic Science: Towards a Definition is based. In order to demonstrate this point, the author attempts to present a historical illustration of how scientific activities gradually emerged in Islam within the first three centuries, i.e. 610-900 AD. The argument developed follows three frameworks that are said to be the foundation of these activities: 1) the Islamic worldview; 2) the Islamic scientific conceptual scheme; and 3) specific terminology of each science. These points are all defined and clarified from an epistemological standpoint.