Forming a theory is like the completion of a puzzle. Each puzzle piece contains meaning of a structural concept. The puzzle pieces are individually colored, however, the interlocking of all the pieces provide a total picture, just as the parts of a nursing theory interconnect to form the whole theory. In the nursing theory puzzle, meanings are absolute when referring to measurable items and quantities; and meanings are abstract when referring to situations and object qualities. Meanings have a direct relationship with the utterance and the linguistic pathways of each civilization. Also, meanings change from one language to another as a word can expand with a similar word or words can interconnect with each other. In this manner, the definition of the meaning can be included under a generalization representing the features of an object, and as a team of relatives or homogenous objects in which all can be rendered in one key word or one paraphrase. The analysis of meaning can be qualitative or quantitative. Nursing theory connects meanings in order to make a whole theory, and to form sentences describing the relationship of meanings, such as a with b, with x, with y, and with z, for a clear logical synthesis of a nursing theory. Sentences describing relationships expressed by nursing theories result from observation, whereas nursing theory structures are not known, because structures constitute all of the meanings and originate from the intellect. As exemplified by putting a puzzle together, four pieces of the puzzle provided a small colored object (or interconnected meanings), but a series of interconnected pieces (or sentences) are required for a systematic view of the entire puzzle picture (or entire nursing theory). As puzzles have a varying number of pieces constituting small, large, and even enormous puzzles, nursing theories have a varying number of components constituting models, grand theory, or metatheory. The puzzle of a comprehensive metatheory of nursing was realized by the Complexity Integration Nursing Theory evolving the meanings, sentences, and structures interconnecting situations and events observed by nurses on a global scale, and incorporating multiple grand theories such as the Human Being, the Individual Essence of the Nurse, and the Social Entirety.

Theories result from each disciplines search and exploration for truth. The term theory evolved from the Greek word theoria signifying a “vision”; however, theories need to do more than foster intellectual visions of how nursing should practice.

Nursing theories are an organized and systematic expression of a set of statements related to questions in the discipline of nursing. Powers and Knapp (1995), defined theory as “a set of statements that tentatively describe, explain, or predict relationships among concepts that have been systematically selected and organized as an abstract representation of some phenomenon (p.170-171). Moreover, Bodie and Chitty (1993) defined theory as “an internally consistent group of relational statements (concepts, definitions and propositions) that present a systematic view about a phenomenon and which is useful for description, explanation, prediction and control”.

The concept of theory was expanded with Chinn and Kramer (1995) defining theory as: “A creative and rigorous structuring of ideas that project a tentative, purposeful, and systematic view of phenomenon” (page 72). The systematic view of a phenomenon provided by a theory encourages validation of existing knowledge as well as discovery of new knowledge. Socialization into a discipline is guided by theories use of language, identification of concepts, definition of relationships, structured ideas, and facilitation of disciplined inquiry, practice and communication, as well as predicting outcomes of practice. Nursing professionals apply theory to describe, explain, predict or prescribe nursing practice.

The nursing profession recognized four levels of theory, including: metatheory, grand theory, middle range theory, and practice theory. Theories are classified by their levels of abstraction along a continuum from the metatheory as the most abstract to practice theories as the least abstract.

The fourth level of theory or Metatheory is the highest level of theory, and is defined by the prefix META, meaning “changed in position”, “beyond”, “on a higher level”, or “transcending,” and refers to the body of knowledge about a body of knowledge or about a field of study such as metaMATHEMATICS (Krippendorff K, 1986). A nursing metatheory presents the most global perspective of the nursing discipline by identifying and evaluating critical phenomena in unique ways. Even though nursing metatheory is very abstract and may not be easily tested, nursing metatheory provides the meanings, sentences, and structures interconnecting situations and events observed by nurses on a global scale. In addition, metatheory may contain grand theories, middle range theories, or practice theories. A nursing metatheory is a nursing theory about nursing theory, as represented with the Complexity Integration Nursing Theory.

Metatheory may be criticized as being limited, without boundaries, abstract and very difficult for practical application. However, a true metatheory in nursing will emerge as a superstructure with multiple practical applications and extensive opportunities for researchers to discover grand theories, mid-range theories, interconnected paradigms, and models, as well as explore how nursing reconstructs and is reconstructed.

The third level of nursing theory, Grand Theory, emphasizes a global viewpoint with a board perspective of nursing practice, and a distinct nursing perspective of nursing phenomenon. Fawcett (1995) defined Grand Theories as the broadest in scope, less abstract than conceptual models but composed of general concepts still relatively abstract, and the relationships cannot be tested empirically. Examples of nursing grand theories are Martha Rogers “Science of Unitary Human Being”; Margaret Newman’s Health as Expanding Consciousness”; Rosemarie Rizzo Parse’s “Theory of Human Becoming”; and the Human Being Theory in the Complexity Integration Nursing Theory. In addition, grand theories may provide the foundation for a mid-range theory. For example, the mid-range theory of “self-care deficit” evolved from Orem’s (1971) grand theory of “self care”.

Middle Range Theories, the second level of nursing theories, are moderately abstract, inclusive, organized within a limited scope; have a limited number of variables, which are testable in a direct manner. The mid-range theories have a stronger relationship with research and practice. The relationship between research and practice, according to Merton (1968), indicated mid-range theories are particularly important for practice disciplines. Additionally, Walker and Avant (1995) maintain that mid-range theories balance this specificity with the conceptual economy normally seen in grand theories. As a result, mid-range theories provide nurses with the “best of both worlds”---easy applicability in practice and abstract enough to be scientifically interesting. Chinn and Kramer (1995, p 216) reported that mid-range theory deals with a relatively broad scope of phenomena but does not cover the full range of phenomena that are of concern within a discipline. They provided the example that the theory of pain alleviation represents a mid-range theory for nursing; it is broader than a theory of neural conduction of pain stimuli but narrower than the goal of achieving high level wellness. Thus, the phenomenon of pain is a mid-range concept of concern for nursing, because pain is one of many phenomena that comprise the global concept of the discipline. Mid-range theories focus on concepts of interest to nurses, and include: pain, empathy, grief, self-esteem, hope, comfort, dignity, and quality of life. Examples of nursing middle range theories are: Rogers’ Theory of Accelerating Change, Roy’s Theory of the Person as an Adaptive System, and King’s Theory of Goal Attainment.

Practice theories, the first level of nursing theory, describe prescriptions or modalities for practice. Four steps are involved to determine practice theories, which include:

-Factor isolating: to identify and describe a phenomenon;
-Factor relating: to identify and describe possible explanations or causes of the phenomenon;
-Situation relating: to predict occurrence of a phenomenon when the cause is present. For example, the post open-heart surgery patient will experience cardiac arrhythmias if the blood potassium level goes below 3.5 meq.; and
-Situation producing control: to prevent occurrence of the phenomenon by controlling or eliminating possible causes. Examples include: pregnant women receive RHO-gram to prevent possible hemolysis in their infants; and the frequent turning and positioning of bed-ridden patients to prevent pressure ulcers.

The Evolving Essence of the Science of Nursing: A Complexity Integration Nursing Theory is a Nursing Metatheory comprised by numerous Grand Nursing Theories, which are:
-The Theory of Nursing Knowledge and Nursing Practice
-The Nursing Theory of Human Being
-The Nursing Theory of Social Entirety
-The Self Observation Methodology

In the Complexity Integration Nursing theory, nursing is both science and art and as Albert Einstein (1927) wrote: “If what is seen and experienced is portrayed in the language of logic, we are engaged in science. If it is communicated through forms whose connections are accessible to the conscious mind, but are recognized intuitively as meaningful, then we are engaged in art”. Moreover, “All philosophy is like a tree”, wrote Descartes. “The roots are metaphysics, the trunk is physics, and the branches are all the other sciences” (cited in: Capra F., 1982, p.55). Thus, Nursing Science is more than a branch of the tree of philosophy, because nursing is nature’s law. So, Nursing as a Science is within the whole philosophy tree, and as Nightingale suggested: ‘Nursing is an art, and if it is to be made an art, it requires as exclusive devotion and as hard a preparation, as any painter’s or sculptor’s work, for what is having to do with the living body - the temple of God’s spirit? It is one of the fine Arts; I had almost said the finest of the fine Arts’ (cited in Donahue 1996:501). Nursing as both Science and Art incorporates all the useful criteria giving to nurses the logic, the analysis, the evaluation, the experience, the reflection, the intuition, and the transcendence.

The Complexity Integration Nursing Theory embodies the past and present theoretical background of the Science of Nursing and goes further and beyond, as we truly believe that: “Very few really seek knowledge in this world. Mortal or immortal, few really ask. On the contrary, they try to wring from the unknown the answers they have already shaped in their own minds - justification, explanations, forms of consolation without which they can’t go on. To really ask is to open the door to the whirlwind. The answer may annihilate the question and the questioner” (Rice A, 1985).