This section will describe meta-perspectives that create a context for the middle range theories in this book. In the first chapter, a connection is made between middle range theory and the unique focus of the discipline of nursing, the structure of the discipline, and grand theories in nursing. In the second chapter, middle range theory is described according to philosophical, theoretical, and empirical levels of abstraction along with ladders depicting the assumptions, concepts, and practice/research applications. The editors have created the ladders of abstraction, thereby interpreting each theorist's perspectives to enable the reader an opportunity for visualizing, comparing, and contrasting each middle range theory as related to the others. The third chapter describes the purpose, structure, and process for evaluating middle range theory. In this chapter, a framework for evaluating the substantive foundations, structural integrity, and functional adequacy of middle range theory is provided emphasizing thoughtful consideration of the theory with empathy, curiosity, honesty, and responsibility.