A systemic approach against reductionism and holism.
System approach (approach/leadership — is the transfer of the developed concept of the "system" in physics to other areas, primarily biology) appeared just for the purpose to deal with reductionism — attempts to describe complex objects without identifying systemic levels and related systemic effects (emergences). Since reductionists do not identify separate systemic levels, they perceive the leading method/function and its discipline/theory/explanation of a lower systemic level (parts of the system, sometimes many levels down from the level of the whole system being considered) as a means to explain the behavior of the entire system as a whole. Thus, reductionists can explain human behavior by chemical and electrical processes that occur in the brain between the main brain cells, neurons. Is that true? Yes, this is true, mathematically absolutely true! But completely useless! Remember the "tail of the herd": it is difficult to understand what operations can be performed on subsystems several levels below if discussing properties of the current level. Although, of course, one can somehow trace how properties of the system follow from properties of its subsystems, and with each level of subsystems, it becomes increasingly difficult to trace. For example, it is still possible to trace that "brick houses are usually warmer than panel houses" if you notice that reinforced concrete panels are strong and therefore thin, while you need to lay many bricks and the walls are thicker there. But if you extend this line to many system levels down to materials — burnt clay, concrete, and reinforcement, the explanation becomes convoluted. Without "panel" and "brick," without "walls" (systems of intermediate systemic levels), explanations will not work.
The behavior of the current level in systems thinking is explained by the interaction of systems from many levels upwards and downwards from the current level, which does not negate the thesis of "simplification" at each transition from higher to lower levels for explanations. However, the system approach does not randomly choose systemic levels for such explanations but takes stable (although non-equilibrium, NESS) physical objects as the systems used for explanations, and also builds explanations fundamentally multi-level/multi-scale — while not skipping the systemic levels to avoid falling into reductionism.
In classical reductionism, there are no many systemic levels in explanations, and only references are made to lower levels. In reductionism, there are no intellectual means to prevent the explanation of human behavior by not even the behavior of neurons in his brain, but by quantum-chemical processes involving electrons and elementary particles of atomic nuclei, lying at the basis of chemical processes, or conversely — by cellular processes, for which chemical processes with cellular molecules are the basis. Explanations of how hormonal activity at the biochemical level affects human behavior are also very fashionable (a human being as a multi-level system higher than the level of biochemistry occurring in the brain). Of course, the biochemistry of brain function affects human behavior, but the connection is so unclear that it requires many systemic levels for clarification: the subject of discussion changes at each systemic level, different activity roles deal with them, and this knowledge is described in different literature. So, a huge amount of pop-psychological literature explaining human behavior solely by low-level neurophysiological mechanisms only leads to misconceptions, explains nothing, and does not provide a basis for reliable work on changing human behavior in the manner of engineering work. Pop psychology is called pop psychology for a reason because it does not adhere to strict mental work standards, it only gives a sense of "explanations". Why does a rocket fly? Because the fuel oxidizes inside it! Why does the brain understand the current lines? Because neurons are firing in it! This is all true, but it's a useless truth for substantive and precise engineering work. For this truth to be useful and precise for engineering work, multi-level (in terms of systemic levels) considerations are needed, and in them, higher levels of consideration should not be skipped to avoid reductionism.
Let's not reduce everything that happens to a person to mental work alone; a person also has an outlet to the physical world through physical work. Dancing, as one of the possible behaviors of a person (other behaviors - life, rest, work), can be "explained" in quotes, reductionist, as a set of chemical processes between molecules in muscle tissue cells or even as a series of movements of hundreds of muscles. Even in this case, we can mention that muscles are controlled by the brain, and the spinal cord is also involved in dancing (life, rest, work). However, the emergence, in this case, of dancing properties (characteristic of the dancer as an agent role when dancing - expressiveness, aesthetics, set of figures, characteristic poses) will not be discussed; there will be no discussion of the dancer and his behavior (dancing). All these reductionist descriptions of dancing as muscle work will be formally logical, but they will be reductionist descriptions, reducing emerging properties to the parts' properties, including properties of parts lying many systemic levels below the level convenient for describing the discussed emergent property.
A herd of cows has a tail (Margaret's cows), but discussing this tail, you will not discuss the herd. By discussing muscles and the spinal cord, you will not discuss the dancer! To discuss the dancer during dancing (and Vasya Pupkin is not a dancer if he does not dance; when Vasya Pupkin has lunch, he is an eater; when he heals, he is a patient; and a dancer only when he dances) you need to describe muscle movement, the whole body's actions in various "non-equilibrium balances," the use of all body inertia in motion (the head weighs 5.4kg, if you move your head properly the body will fly after it roughly the same way it will fly after a watermelon of similar weight), the principles of dance style (and here aesthetics need to be engaged, and also culturally conditioned style), and how these principles are embodied in individual movements (the dance's lexicon), and how these movements are assembled into a complete dance performance (choreography - here), and why such dances are repeated in various dance master communities (for example, why tango is danced in very different places on the planet, and you can recognize that it is tango, and people-agents who dance it somehow decide to learn to dance and become tango masters - we are already discussing the community level, much higher than the muscle level!). Each step of this discussion is made with individual objects, it is impossible to explain "how a dancer is built" through "muscles and nerves," the dancer's behavior is inexpressible through the behavior of "muscles and nerves." If you are describing the design of a city district, you cannot describe it through the arrangement and form of bricks, and even the walls in the buildings. You have to describe the block through the arrangement and shape of buildings and courtyards, lawns and squares, vacant lots and driveways. Blocks, dancers, herds — one must be careful about which "systemic level"/"part level of an object" we are trying to describe the behavior of a particular system as a whole.
Reductionist methods (describing a herd in terms of tails and horns, not cows) still worked, but worked poorly. If reductionists accidentally guessed the convenient systemic level (a dancer as one engaging in methods of maintaining posture/"dancing posture," dance steps in rhythm, assuming some positions as a couple when it comes to social dances, a block as consisting of buildings and courtyards, a herd of cows and bulls) — reductionist methods worked, and if they did not guess (a dancer from muscles and bones, a block from bricks and grass on lawns, a herd from ears, feet, and tails), then nothing good happened. It looked like "reductionism — a blessing!" (and listing successful cases) and "reductionism — harm!" (and listing cases of failure).
A classic example of the first systems with which system thinking was honed at the moment of its formation as a general system theory by Ludwig von Bertalanffy is a blooming meadow in spring. A hundred species of plants and animals, soil, remnants from the flood of puddles and small swamps. How to discuss the seasonal changes happening on the meadow? By the biochemistry of the interaction of all living cells of all animals and plant organisms on the blooming meadow? It is obvious that this does not work, although it is formally correct, but how to translate this intuitively understood "does not work, although formally correct" into an explicit principle level? This is where the concepts of systemic levels and emergence come in handy, and thus the "system approach" emerged as a transfer of the developed concept of the "system" in physics to other subject areas. Discussing such a complex system as a blooming meadow became easier. This complex object began to "fit into the head"; thinking about it "spread out on the shelves."
Emergence should be distinguished from synergy — the effect of the mutual enhancement of properties. If when merging two companies with small profits we observe that their mutual utility and profit sharply increase, then we observe simply a stronger resulting company; there is no systemic effect/emergence (the appearance of a new property, a new characteristic, a new object of interest from the interaction of parts of this whole); there is simply the synergy of these original companies in terms of old properties. No new properties emerged, old properties were just strengthened. There is no systemic effect, no emergence, no new object and new roles associated with new properties of the merged synergistic parts of this whole. However, there is synergy: properties have been enhanced! The system approach has nothing to do with it.
But if you combine bricks and cement with water in the right form, a house will appear from their interaction — and you can discuss rooms, house tenants, which are impossible to discuss in terms of a simple mortar and bricks. Bricks in cement and water do not enhance anything, do not contribute to anything; cement in bricks does not enhance anything, but if you take them in sufficient and proper quantity and combine first cement with water (getting a solution: the properties of the solution are irreducible to the properties of water and cement), and then bricks with the solution, a house will be built — the house's properties will be incomparable with the properties of bricks, cement, and water. And there is no synergy in this case, that is, there is no mutual strengthening of the properties of cement, water, and bricks when they are combined in two levels: "bricks plus "cement plus water.""
People live in houses; they do not live in bricks, even when folded in a pile. Although formally, they live in bricks with a solution (reductionism!), it is difficult to discuss life in this language. For example, a house has an architectural style (in terms of architectural construction, a visual image) — modern, baroque — while these architectural style elements do not exist for bricks with a solution; they are not discussed in terms of bricks and solution. But the elements of this architectural style are just a particular arrangement of bricks, pure truth. This is also reductionism, "true but useless truth"; it is impossible to discuss a house this way! Synergy (the combination of parts without the emergence of new qualities but a change in the old qualities of the parts) can be discussed within the framework of reductionism, while the emergence/systems thinking precludes reductionism.
The second mistake that systemic thinking corrected is the reverse of reductionism — holism. Those not well-versed in systemic thinking (and no doubt inherited by AI-agents) attribute it to holistic teachings — that explain the behavior of a system by the behavior of its supersystem. Dancers dance the way they do now precisely because human society provides the existence of a dance subculture (for spectators, for themselves, and even for friends - dancers in harem leisure developed precisely as entertainment). This dance subculture as a set of memes in people's minds (and now on other media - film, video on social networks) makes people dance as they do, and people's muscles and nerves respond to this "cultural command," helping to reproduce dancing as a way to spread these memes, they will not go away, for "the behavior of lower systemic levels completely depends on what happens outside them," the main idea of holism. For holism, a dance culture emerges not because people dance and the aggregate of their behavior patterns (methods of work), performances, and reflections on dances are called culture, but conversely, for holism — people dance (the phenomenon of dance culture) because it is demanded by the dance culture (a meme of dance culture) as a set of all ideas/memes/thoughts about dances and related human behavior. For holism, ideas about posture, dance steps in rhythm, ideas about "muscle twitches," the musculoskeletal system, and its condition in dances are declared irrelevant. For holism, all this "will somehow automatically adapt to the public demand" (and do not ask, what is "public demand": the ideas of high levels associated with communities and societies are quite vague, there are no good ontologies, so the language is more artistic, easy to fantasize, including anthropomorphize society — and attribute to it, for example, a "demand").
Even not going into detailed explanations, why pure holism is as big a mistake as reductionism, because the absurdity of holism's statements is quickly revealed, and therefore it is less common. But it still occurs, holism is very common in the social sciences. It is difficult to convince a thermal locomotive engineer that the steam locomotive has such low efficiency during operation because it is made so by the railway tracks and stations, not physical processes that determine the locomotive's efficiency compared to the efficiency of an electric locomotive. But a humanist can easily claim that a dancer's dance performance is as it is — a direct consequence of the "public need." What is this "public need," "society's demands" is not even worth discussing. But the words are familiar and do not raise questions for humanists. Although there are questions: what is the "need" of "society" of many individual people with completely different ideas about dances, and not only dances, and how does it manifest itself in a concrete performance in terms of muscle work and nerves ?!
Systemic thinking is associated with holism because multiple levels of interaction are taken into account in multi-level reasoning (including inevitable conflicts leading to the need for multi-level optimization of system configurations of all levels, and the result here will be the disorganization of these configurations and an increase in system complexity during evolution. Systemic thinking recognizes the existence of higher levels, and their influence on lower ones (the influence of the whole on the parts), as in holism. However, systemic thinking also takes into account the existence of lower levels, their influence on the upper (the influence of parts on the whole), as in reductionism. In this case, simultaneously, on many systemic levels from top to bottom and from bottom to top!
In modern (third-generation) system thinking, it is also said that all these influences are multi-levelly optimized during evolution: because all these parts and wholes appeared as they are, during evolution (bio/Darwinian, memetic, techno). At the same time, it is necessary to consider time scales that are thousands of times longer than time scales in the immediate interaction of systems during their use — in a dance, a figure lasts half a second, but the appearance of the figure's evolution took years, and sometimes even decades, and the appearance of muscles and nerves of dancer agents on more slowly changing lower levels took millions of years, and development along this line continues. Thus, there is already a six-armed dance agent performance: two of their own arms and four mechanical arms from a backpack with manipulators, the evolution of the dancing agent continues, but it is not a very fast evolution.
Systems thinking is both reductionist and holistic at the same time. Well, or not reductionist, not holistic. It resolves the contradictions between these two approaches to explaining system behavior.