Holism is the idea that systems, whether biological, psychological, or social, are best understood as complete wholes rather than as collections of individual parts. The core principle is that a whole has properties and behaviors that cannot be predicted or explained by examining its components in isolation. This concept applies across philosophy, medicine, psychology, and biology, and it shapes how millions of people think about health and well-being.
Where the Idea Came From
The term was coined in 1926 by South African philosopher Jan Christiaan Smuts, who derived it from the Greek word “holos,” meaning whole. In his book “Holism and Evolution,” Smuts described holism as “the ultimate principle of the universe” and “the operative factor in the evolution of wholes,” extending from molecules to humans and encompassing both organic and inorganic structures. His central argument was that the development of wholes is the fundamental nature of reality, a basic tendency of the universe. All wholes, in his framework, are self-creative and striving toward greater complexity.
While Smuts gave the concept a name, the underlying idea is ancient. Traditional healing systems across cultures have long treated the body, mind, and spirit as inseparable. What Smuts formalized was the philosophical argument that you lose something essential when you break a system down into isolated pieces.
Holism vs. Reductionism
The easiest way to understand holism is to contrast it with reductionism, its philosophical opposite. Reductionism says you can understand any complex thing by studying its smallest parts. Take a clock apart, understand each gear, and you understand the clock. Holism says that approach misses something: the gears only tell time when they work together, and that timekeeping function is a property of the whole system, not of any single gear.
In biology, this debate plays out constantly. A reductionist might study a single gene to understand a disease. A holist would argue that gene expression is better studied during infection of a living host, in the context of a network of interacting genes monitored over time. Theoretical biologists like Stuart Kauffman have emphasized that complex systems give rise to emergent properties, novel behaviors that are not predictable from examining individual components alone. A fundamental principle of systems biology is that cellular and organismal parts are interconnected, so their structure and behavior must be examined in intact organisms rather than as isolated pieces.
Holism in Psychology
One of the most influential applications of holistic thinking in healthcare is the biopsychosocial model, introduced by psychiatrist George Engel in the late 1970s. Engel argued that to understand and respond adequately to a patient’s suffering, clinicians must attend simultaneously to biological, psychological, and social dimensions of illness. A biochemical change in the body does not automatically translate into an illness. Whether someone actually gets sick, and how severely, depends on the interaction of factors at the molecular, individual, and social levels.
Engel was pushing back against three tendencies in medicine. First, the separation of body and mind, treating the physical body as a machine disconnected from the person’s emotions and life story. Second, an excessively materialistic orientation that ignored or devalued anything that couldn’t be explained at the cellular level. Third, the assumption that disease always starts with a single physical cause. His own research showed that fear, rage, neglect, and attachment had measurable physiological and developmental effects on the whole organism.
The practical impact of this model is significant. Psychosocial variables turn out to be more important determinants of who gets sick, how severe the illness becomes, and how it progresses than a purely biological view would predict. Schizophrenia offers a clear example: genetics plays a role in causing it, but no clinician would ignore the social factors that might trigger or contain its symptoms. Even tuberculosis, caused by a specific bacterium, is influenced by sustaining forces like low caloric intake and precipitants like low body temperature.
Holism in Medicine and Health
In healthcare, holistic thinking shows up in several overlapping but distinct categories. The National Institutes of Health draws clear lines between them. A complementary approach is a non-mainstream practice used alongside conventional medicine. An alternative approach replaces conventional medicine entirely. Integrative health brings conventional and complementary approaches together in a coordinated way, with an emphasis on treating the whole person rather than one organ system.
The NIH also uses the term “whole person health,” which refers to improving and restoring health across multiple interconnected domains: biological, behavioral, social, and environmental, rather than just treating disease.
In practice, a holistic treatment plan for something like chronic pain might combine conventional care with nutrition changes, sleep optimization, stress reduction, yoga or tai chi, and mindfulness techniques. Research shows that mindfulness approaches, including those used in cognitive behavioral therapy, can reduce the intensity of chronic pain and improve physical function. Relaxation methods like deep breathing, guided imagery, and progressive muscle relaxation are recommended by organizations like the American College of Physicians as early steps in managing chronic low-back pain.
Lifestyle medicine formalizes this thinking around six pillars: a whole-food eating pattern, physical activity, restorative sleep, stress management, avoidance of risky substances, and positive social connections. What makes this approach distinctly holistic is that lifestyle changes directed at one disease tend to benefit others as well. Unlike a medication designed for a specific condition, healthy habits have broad effects across the body. Research on long-lived populations shows that adherence to these principles, including strong social bonds, natural movement, wise eating, and having a sense of purpose, impacts not only years of life but quality of life in those years.
Holistic Nursing
Holism is formalized in nursing through the American Holistic Nurses Association, which bases its standards of practice on five core values: holistic philosophy and education, holistic ethics and research, nurse self-care, holistic communication with cultural competence, and the holistic caring process. The self-care value is notable because it requires nurses themselves to maintain their own health and personal awareness in order to effectively care for others. The caring process expands traditional nursing assessment to address client patterns, problems, and needs in a broader, more relationship-centered way.
Limitations and Valid Criticism
Holism as a philosophy is broadly accepted across science and medicine. But “holistic” as a marketing term on products and services is far less regulated, and that gap creates real problems. Many complementary and alternative treatments lack solid research on which to base sound decisions. The dangers and possible benefits of numerous holistic treatments remain unproven, and many forms of alternative medicine are rejected by conventional medicine because their effectiveness has not been demonstrated through controlled clinical trials.
The most serious concern is what researchers call “opportunity cost.” People who choose unproven alternative treatments may forgo effective conventional ones, believing they’ve chosen something safe and effective when they may be getting treatments with no demonstrated benefit. Good holistic medicine, as the research community defines it, should be inquiry-driven, open to new approaches, favor less invasive interventions when possible, and still be grounded in good science. People should be free to choose their healthcare approach, but they need accurate information about the safety and efficacy of whatever method they choose.
The strongest applications of holism in healthcare are those that complement rather than replace evidence-based medicine: treating the whole person while still using proven treatments for specific diseases.