The treatment of the subject in this monograph is selective and interpretive, motivated and guided by some philosophical and methodological considerations, such as those centered around the notions of metaphysics, causality, and ontology, as well as those of progress and research programme. In the literature, however, these notions are often expressed in a vague and ambiguous way, and this has resulted in misconceptions and disputes. The debates over these notions (and related motivations) concerning their implications for realism, relativism, rationality, and reductionism have become ever more vehement in recent years, because of a radical reorientation in theoretical discourses. Thus, it is obligatory to elaborate as clearly as I can these components of the framework within which I have selected and interpreted the relevant material. I shall begin this endeavor by recounting in Section 1.1 my general view on science. After expounding topics concerning the conceptual foundations of physics in Sections 1.2–1.4, I shall turn to my understanding of history and the history of science in Section 1.5. The introduction ends with an outline of the main story in Section 1.6.