The Spiral of Nursing Theory―“Theories are nets: only they who cast will catch.”

　Nursing theory plays a critical role in the advancement of nursing in healthcare. In the late 19th century, Britain's Florence Nightingale professionalized nursing practice by enacting her theoretical focus on the significance of the physical and social environment in human health and well-being. During the early 20th century, theoretical innovation in nursing lost momentum and nursing practice became more intellectually, emotionally and politically dependent upon medicine. However, as the 20th century progressed, nursing leaders in theoretical thinking helped clarify and energize nursing's advancement in education, research, and practice. Hildegard Peplau's 1952 theory of interpersonal relations introduced a major focus on the nurse-patient relationship, which remains a defining focus of nursing practice. Other theorists followed. The purpose of this article is to provide an overview of the theoretical dimensions of nursing and inspire all nurses to participate in building scientific knowledge for their discipline. Without sustained attention to the theoretical basis of nursing, the discipline will lose its standing as a unique and innovative science in healthcare.