This book develops a conception of science as a multi-dimensional practice, which includes experimental action and production, conceptual-theoretical interpretation, and formal-mathematical work. On this basis, it addresses the topical issue of scientific realism and expounds a detailed, referentially realist account of the natural sciences. This account is shown to be compatible with the frequent occurrence of conceptual discontinuities in the historical development of the sciences. Referential realism exploits several fruitful ideas of Jürgen Habermas, especially his distinction between objectivity and truth. It builds on a in-depth analysis of scientific experiments, including their material realization, and it is developed through an extensive case study in the history and philosophy of quantum mechanics. The new postscript explains how the book relates to several important issues in recent philosophy of science and science studies.