Greek ὅλος whole
Holism (from ὂλος holos, a Greek word meaning all, whole, entire, total), is the idea that natural systems (physical, biological, chemical, social, economic, mental, linguistic, etc.) and their properties, should be viewed as wholes, not as collections of parts. This often includes the view that systems somehow function as wholes and that their functioning cannot be fully understood solely in terms of their component parts.
The term holism was coined in 1926 by Jan Smuts. Reductionism is sometimes seen as the opposite of holism. Reductionism in science says that a complex system can be explained by reduction to its fundamental parts. For example, the processes of biology are reducible to chemistry and the laws of chemistry are explained by physics.
Social scientist and physician Nicholas A. Christakis explains that "for the last few centuries, the Cartesian project in science has been to break matter down into ever smaller bits, in the pursuit of understanding. And this works, to some extent...but putting things back together in order to understand them is harder, and typically comes later in the development of a scientist or in the development of science."
The term holism was coined in 1926 by Jan Smuts, a South African statesman, in his book, Holism and Evolution. Smuts defined holism as "The tendency in nature to form wholes that are greater than the sum of the parts through creative evolution."
The idea has ancient roots. Examples of holism can be found throughout human history and in the most diverse socio-cultural contexts, as has been confirmed by many ethnological studies. The French Protestant missionary, Maurice Leenhardt coined the term cosmomorphism to indicate the state of perfect symbiosis with the surrounding environment which characterized the culture of the Melanesians of New Caledonia. For these people, an isolated individual is totally indeterminate, indistinct and featureless until he can find his position within the natural and social world in which he is inserted. The confines between the self and the world are annulled to the point that the material body itself is no guarantee of the sort of recognition of identity which is typical of our own culture.
In the latter half of the 20th century, holism led to systems thinking and its derivatives, like the sciences of chaos and complexity. Systems in biology, psychology, or sociology are frequently so complex that their behavior is, or appears, "new" or "emergent": it cannot be deduced from the properties of the elements alone.
Holism has thus been used as a catchword. This contributed to the resistance encountered by the scientific interpretation of holism, which insists that there are ontological reasons that prevent reductive models in principle from providing efficient algorithms for prediction of system behavior in certain classes of systems. Holism has also been described as "a soapy term which evades necessary conflict," in accordance with its inventor's philosophy of white supremacy and exclusion of South Africans from political rights. Although it can also be suggested that a thinker's beliefs in one area should not be used to dismiss their beliefs in another. For example,Mahatma Gandhi's racist beliefs should not be used to dismiss the value he placed on non-violent resistance.
Scientific holism holds that the behavior of a system cannot be perfectly predicted, no matter how much data is available. Natural systems can produce surprisingly unexpected behavior, and it is suspected that behavior of such systems might be computationally irreducible, which means it would not be possible to even approximate the system state without a full simulation of all the events occurring in the system. Key properties of the higher level behavior of certain classes of systems may be mediated by rare "surprises" in the behavior of their elements due to the principle of interconnectivity, thus evading predictions except by brute force simulation. Stephen Wolfram has provided such examples with simple cellular automata, whose behavior is in most cases equally simple, but on rare occasions highly unpredictable.
Complexity theory (also called "science of complexity"), is a contemporary heir of systems thinking. It comprises both computational and holistic, relational approaches towards understanding complex adaptive systems and, especially in the latter, its methods can be seen as the polar opposite to reductive methods. General theories of complexity have been proposed, and numerous complexity institutes and departments have sprung up around the world. The Santa Fe Institute is arguably the most famous of them.