This chapter serves as the introduction to the book by presenting its aim, research questions, structure and theses. The aim of this book is to show why neither previously and currently predominant variants of realism nor the usual forms of anti-realism in philosophy of science are argumentatively sufficient and how this ongoing debate motivates a new realism in philosophy of science. This scientific realism can provisionally be understood as the position according to which scientific statements and theories have a truth value regardless of whether we (can) establish it in our research, and according to which scientific entities described by theories exist and can be known how they are in nature, independently of us. Anti-realism, in relation to the natural sciences, denies this thesis. As a method, it makes sense to develop a positive, new possibility from a critique of the current state of the debate in philosophy of science: new realism in philosophy of science, or new scientific realism for short. The aim of my work is not to elaborate such a philosophy in detail, but to show that a new solution must be sought and can be achieved by using ideas taken from the debate about new realism in ontology and epistemology. I do not claim here to follow the path of new scientific realism to its conclusion, but to take a first step in this direction. My aim is to chart a course that makes a new form of realist philosophy of science possible. In order to achieve the above-mentioned goals, two central questions must be answered: Which arguments, premises, theses and philosophical positions belonging to the debate on realism and anti-realism in philosophy of science to date give rise to the stalemate in which none of the proposals are entirely convincing? And: Which concepts, arguments and insights derived from new realism can be introduced to philosophy of science and in what way, in order to resolve the stalemate? Figuratively speaking, these two questions are the fixed stars of the two parts of this book.