In the past nursing was based on principles borrowed from the physical and social sciences and other disciplines. Today, however, there is a body of knowledge that is uniquely nursing, while this was not always same, amount of investigation and analysis of nursing care has expanded rapidly in recent years. Nursing is no longer based on task orientation, situation or trial and error but it increasingly relies on researcher as a basis for practice; now we have several theoretical models of nursing which have been developed by our own nursing theorists.

This book is a synthesis and extension of what we believe that theoretical models now serve a newer and more important role within nursing. Nursing theories and model have come to be understood on the embodiment of nursing philosophies, presenting nursing beliefs understanding and purposes it has been believed that theoretical models are excellent and tangible sources of the perspective of nursing across time. Certainly some of the models serve as sources for extensive programmes of research, as curriculum organizers and as templates for practice. It has been suggested that the nursing perspectives may be used to guide knowledge development within nursing. Since it fulfils one of the criteria of the profession that there is special body of knowledge which continuously enlarges the body of knowledge uses and improves its techniques of education and service by the use of scientific method to fulfil the purpose. I have tried my level best to select some of the important contributions of nurse theorists and put it in an understandable language so that every one will be aware and acquainted with knowledge of nursing theories, which help them in nursing practice, nursing education and nursing research.

When Nursing develops its own theory, validates research knowledge in the practice setting and relies on this knowledge to direct nursing practice, it will be recognized as an independent autonomous profession.8

I hope this book will continue to serve not only nursing student of all levels for whom it is intended but also nursing teachers and practitioners. Theory improves nursing practice by describing, explaining, predicting and controlling phenomena of interest to nurses. Theory allows professional autonomy by guiding the practice, education and research functions of the profession. The study of theory helps develop analytical skills, challenges, thinking and clarifying values and assumptions.

I am aware of manifold reasons, error might be crept in and shall feel oblige, if such errors are brought to my notice. I sincerely welcome constructive criticism from readers, that would help me to enrich myself and suggestions will be incorporated in the next edition.