For decades, nursing educators have invested heavily in developing a philosophy and conceptual framework specific to a given school of nursing, regardless of the level of nursing education. Consequently, there is a great deal of variability, and often opposing schools of thought, across schools of nursing. A theoretical foundation applicable across nursing education programs, therefore, has emerged as a significant missing factor. This missing theoretical piece is of critical importance for the student seeking nursing education at a variety of colleges and universities and through multiple programs such as practical nurse, associate degree nurse, baccalaureate degree nurse, masters degree nurse and even as a doctorate prepared nurse.
Traditionally, the nursing profession had been a science subsumed from other disciplines with non-mathematical and non-computational research originating from nurses. Recently, however, nursing science has broken out of the traditional mold and has added a strong scientific and theoretical foundation and mathematics are becoming an integral component of nursing. Nursing scientists have recognized the value of using mathematics for graphically representing abstract conceptualizations, particularly for describing, explaining, and predicting nursing practice (Walker & Avant, 1995). For instance, the Theory of Nursing Knowledge and Nursing Practice, a mathematics based approach to nursing education, when utilized refines and enhances the structural foundation for nursing curriculum, nursing courses, and nursing textbooks, emerging a new viewpoint of the Science of Nursing in the most global perspective. Furthermore, this global perspective that The Theory of Nursing Knowledge and Practice illustrates, subsuming the parts of the Nursing Knowledge and Nursing Practice, creating a whole. The whole centered to the Human Being, the nurse as individual human being, and the implementation of this understanding in the community and in the Social Entirety Nursing Theory, creating The Complexity Integration Nursing Theory, a Nursing Metatheory. Paille M and Pilkington FB (2002) assert that when one's perspective is the human science paradigm, and particularly, the human becoming theory, one person can and does make a difference in global health. As Metatheory, the Complexity Integration Nursing Theory evolves new viewpoints, approaches and creative tools in order to utilize the Human Being’s perspective. In this way, the four metaparadigms of the Nursing Science, which is the person, the environment, the health and the nursing (Powers & Knapp, 1990), emerge within their interrelations as self-organized networks within the Nursing Science’s network.

The Theory of Nursing Knowledge and Nursing Practice

During the early 1990’s, a unique opportunity to enhance and add to the theories of nursing science emerged with the advent of the supercomputer and its capabilities for dealing with tarabyte-sized databases. A nursing scientist leading a transprofessional team resulted in new tools and methodologies necessary for analyzing large-scale databases and the development of a theory regarding nursing knowledge and nursing practice. The Theory of Nursing Knowledge and Nursing Practice evolved during the development of Nurmetrics and computational nursing, which introduced a new era for nursing science with emphases on mathematical form, statistical analysis, and computer simulation. Serving as an initial foundation for Nurmetrics was the evolution of a nursing theory utilizing mathematical form (Meintz, et. al.). The Theory of Nursing Knowledge and Nursing Practice expressed through mathematical form analyzes nursing science as it relates to nursing practice; whether it is clinical nursing practice, nursing education, nursing administration, or nursing research. The Theory is a revolutionary manner of understanding the intricacies of nursing knowledge with a mathematical statement. Development of the Theory delineates the diverse factors that constitute professional nursing practice, to explain the relationship between the separate elements, and to predict nursing practice patterns through examination of identified variables. The Theory of Nursing Knowledge (Figure 1) elucidates the uniqueness of the nursing profession by systematically identifying the fulcrums of practice.
NF stands for the Nursing Foundation, a combination of knowledge from both the sciences and humanities. The sciences contribute the empirical knowledge base procured by the science of nursing and associated disciplines such as biology, the physical sciences, medical science, and chemistry. Behavioral, social or natural sciences supply abstract scientific theories. For example, the humanities contribute knowledge from the philosophical and cultural studies that investigate human constructs and concerns, as contrasted to physiological processes such as physics or chemistry.
Methodology (M) applies a methodology for problem solving to a specific practice domain such as in clinical practice the staff nurse uses the nursing process or Outcome, Process, and Test (OPT) model, strategic thinking for nursing administration, scientific inquiry for nursing research, or adult learning theory for nursing education.
Nursing Essence (NE) represents the evolution of nursing as a profession and is defined according to the practice domain. NE includes the principles of the science of nursing, legal parameters, the definition of person, environment, health, and nursing; technical skills; and all other esoteric components of nursing practice. Additionally, nursing essence accounts for the various existing nursing conceptual models and nursing theories. The conceptual models and the nursing theories may provide the basis for clinical practice for some nurses (i.e. Johnson’s Behavioral System Model, King’s General Systems framework, Levine’s Conservation Model, Neuman’s Systems Model, Orem’s Self-Care Framework, Rogers’ Science of Unitary Human Beings, Roy’s Adaptation Model, Leininger’s Theory of Culture Care Diversity and Universality, Newman’s Theory of Health as Expanding Consciousness, Parse’s Theory of Human Becoming, Orlando’s Theory of the Deliberative Nursing Process, Wiedenbach’s Clinical Nursing: A Helping Art, Henderson’s Nature of Nursing, Travelbee’s Interpersonal Aspects of Nursing, Peplau’s Theory of Interpersonal Relations, Watson’s Theory of Human Caring, and so forth). Thus, Nursing Essence is defined differently for each of the nursing practice domains, including clinical nursing practice, nursing education, nursing administration, and nursing research.
Disciplined Inquiry (DI) refers to investigation or experimentation aimed at the discovery and interpretation of facts, revision of accepted theories or law in the light of new data, and the practical application of new or revised theories or laws. Nursing knowledge is influenced by disciplined inquiry (or research) from the nursing sciences and associated disciplines.
NK is Nursing Knowledge, the understanding of nursing as a science and an art. Therefore, nursing knowledge equals the nursing foundation (derived from the combination of knowledge from the sciences and the humanities), plus the nursing essence, plus methodology, and plus disciplined inquiry.
The Theory of Nursing Knowledge is applicable to practice through the following formula:
(NK) (I) = P (Figure 2)
Here, (I) represents the individual nurse’s integration and synthesis of nursing knowledge through cognitive, psychomotor, and affective/spiritual domain of self. Whereas, (P) represents the depth and breadth of nursing practice, which increases or decreases according to the application of nursing knowledge to this integration. The depth and breadth or nursing practice (P) is determined by the individual nurse’s (I) integration and synthesis through domains of cognitive, psychomotor, affective/spiritual domains of self, times nursing knowledge (NK). Therefore, if P = Y, and (NK) (I) = X, then the greater the X, the greater the Y. As X increases (or decreases) Y increases (or decreases). X is positively (or negatively) related to Y. The reverse is not true because this is a nonreversible, or unidirectional causality.

The final synthesis statement of the Theory of Nursing Knowledge and Nursing Practice affirms that:
The degree of change in nursing practice, which an individual nurse emits, is directly related to the degree of integration and synthesis of nursing knowledge, which includes: nursing foundation (science and humanities) plus nursing essence plus methodology plus disciplined inquiry.