This third edition is essentially for begining nursing students. It is not a comprehensive text in the sense of covering all aspects of nursing knowledge and practice required in the course of a basic education programme; rather, it encourages a logical mode of thinking about nursing in the framework of a model for nursing. The presentation of the book itself has been rearranged and its content substantially revised and updated. Section one has been changed. Its introductory chapter emphasizes the link between nursing and health - a point which is stressed increasingly by the World Health Organization. The content of the second chapter is new. It includes a discussion, albeit brief, of some of the other internationally well-known models for nursing, in order to provide an understanding of the context in which the Roper, Logan and Tierney model can be considered. Section 2 has been considerably altered; the objective here being to present this model more clearly, incorporating some of the refinements which have been made since the last edition. It commences with a chronological account of the background to the model showing how it developed from research. Subsequently, the model of living and the model for nursing are discussed sequentially. In the previous editions they were separated by three brief chapters introducing some concepts about biology, psychology and sociology. This may have been more appropriate when the first edition was published, but increasingly nursing students are expected to study the biological and social sciences as foundation subjects, so these three chapters have been omitted. Instead the third edition emphazises more than previously, the application of such knowledge in the context of factors affecting the ALs, a component of the model Section 3, as before, consists of 12 chapters, one devoted to each of the 12 `Activities of Living', the main component of the model. All of these chapters have been extensively revised, obviously to update the content but also to reflect the five components of the model more clearly than in the second edition. The first half of each chapter discusses the nature of AL, mainly in the context of healthy living; the second half provides selected examples of the problems related to the ALs which can be caused by illness.