General System Theory: Foundations, Development, Applications

by Ludwig Von Bertalanffy

So we have to content ourselves with an “explanation in principle,” a qualitative argument which, however, may lead to interesting consequences.

According to the law of instability, many organizations are not in a stable equilibrium but show cyclic fluctuations which result from the interaction of subsystems.

A unitary conception of the world may be based, not upon the possibly futile and certainly farfetched hope finally to reduce all levels of reality to the level of physics, but rather on the isomorphy of laws in different fields.

We come, then, to a conception which in contrast to reductionism, we may call perspectivism. We cannot reduce the biological, behavioral, and social levels to the lowest level, that of the constructs and laws of physics. We can, however, find constructs and possibly laws within the individual levels.

The unifying principle is that we find organization at all levels.

Very similar general concepts have been independently developed by investigators who have been working in widely different fields. These correspondences are all the more significant because they are based upon totally different facts. The men who developed them were largely unaware of each other’s work. They started with conflicting philosophies and yet have reached remarkably similar conclusions.

Human society is not a community of ants or termites, governed by inherited instinct and controlled by the laws of the superordinate whole; it is based upon the achievements of the individual and is doomed if the individual is made a cog in the social machine. This, I believe, is the ultimate precept a theory of organization can give: not a manual for dictators of any denomination more efficiently to subjugate human beings by the scientific application of Iron Laws, but a warning that the Leviathan of organization must not swallow the individual without sealing its own inevitable doom.

In cases 1 and 2, the complex may be understood as the (cf. pp. 66ff.) sum of elements considered in isolation. In case 3, not only the elements should be known, but also the relations between them. Characteristics of the first kind may be called summative, of the second kind constitutive.

The meaning of the somewhat mystical expression, “the whole is more than the sum of parts” is simply that constitutive characteristics are not explainable from the characteristics of isolated parts. The characteristics of the complex, therefore, compared to those of the elements, appear as “new” or “emergent.”

While we can conceive of a sum as being composed gradually, a system as total of parts with its interrelations has to be conceived of as being composed instantly.

It is an interesting consequence that, in Volterra’s equations, competition of two species for the same resources is, in a way, more fatal than a predator-prey relation—i.e., partial annihilation of one species by the other. Competition eventually leads to the extermination of the species with the smaller growth capacity; a predator-prey relation only leads to periodic oscillation of the numbers of the species concerned around a mean value. These relations have been stated for biocoenotic systems, but it may well be that they have also sociological implications.

If we are speaking of “systems,” we mean “wholes” or “unities.” Then it seems paradoxical that, with respect to a whole, the concept of competition between its parts is introduced. In fact, however, these apparently contradictory statements both belong to the essentials of systems. Every whole is based upon the competition of its elements, and presupposes the “struggle between parts” (Roux).

The concepts just indicated have often been considered to describe characteristics only of living beings, or even to be a proof of vitalism. In actual fact they are formal properties of systems.

You cannot sum up the behavior of the whole from the isolated parts, and you have to take into account the relations between the various subordinated systems and the systems which are super-ordinated to them in order to understand the behavior of the parts. Analysis and artificial isolation are useful, but in no way sufficient,

As a rule, the organization of physical wholes, such as atoms, molecules, or crystals, results from the union of pre-existing elements. In contrast, the organization of biological wholes is built up by differentiation of an original whole which segregates into parts. An example is determination in embryonic development, when the germ passes from a state of equipotentiality to a state where it behaves like a mosaic or sum of regions which develop independently into definite organs.

Mechanization, however, is never complete in the biological realm; even though the organism is partly mechanized, it still remains a unitary system; this is the basis of regulation and of the interaction with changing demands of the environment. Similar considerations apply to social structures.

Behavior as a whole and summative behavior, unitary and elementalistic conceptions, are usually regarded as being an titheses. But it is frequently found that there is no opposition between them, but gradual transition from behavior as a whole to summative behavior.

All these facts may be observed in a variety of systems. Nicolai Hartmann even demands centralization for every “dynamic structure.” He therefore recognizes only a few kinds of structures, in the physical realm, those of smallest dimensions (the atom as a planetary system of electrons around a nucleus) and of large dimensions (planetary systems centralized by a sun).

Thus strictly speaking, biological individuality does not exist, but only progressive individualization in evolution and development resulting from progressive centralization, certain parts gaining a dominant role and so determining behavior of the whole.

Here, too, the correct conception is that any function ultimately results from interaction of all parts, but that certain parts of the central nervous system influence it decisively and therefore can be denoted as “centers” for that function.

happenings can, in fact, be considered and described as being determined not by actual conditions, but also by the final state to be reached.

In other words, the directedness of the process towards a final state is not a process differing from causality, but another expression of it.

physics makes ample use of such final-value formulas because the fact is mathematically clear and nobody attributes an anthropomorphic “foresight” of the goal to a physical system. Biologists, on the other hand, often regarded such formulas as somewhat uncanny, either fearing a hidden vitalism, or else considering such teleology or goal-directedness as “proof” for vitalism.

This matter was frequently misinterpreted even by philosophers. From E. von Hartmann to modern authors like Kafka (1922) and myself, finality was defined as the reverse of causality, as dependence of the process on future instead of past conditions.

Direction of events towards a final state which can be expressed as if the present behavior were dependent on that final state.

Whilst man-made machines work in such a way as to yield certain products and performances, for example, fabrication of airplanes or moving a railway train, the order of process in living systems is such as to maintain the system itself.

There is, however, yet another basis for organic regulations. This is equifinality—i.e., the fact that the same final state can be reached from different initial conditions and in different ways. This is found to be the case in open systems, insofar as they attain a steady state. It appears that equifinality is responsible for the primary regulability of organic systems—i.e., for all those regulations which cannot be based upon predetermined structures or mechanisms, but on the contrary, exclude such mechanisms and were regarded therefore as arguments for vitalism.

An important part of those phenomena which have been advanced as “proofs of vitalism,” such as equifinality and anamorphosis, are consequences of the characteristic state of the organism as an open system, and thus accessible to scientific interpretation and theory.

General system theory therefore is not a catalogue of well-known differential equations and their solutions, but raises new and well-defined problems which partly do not appear in physics, but are of basic importance in non-physical fields. Just because the phenomena concerned are not dealt with in ordinary physics, these problems have often appeared as metaphysical or vitalistic.

The structure of reality is such as to permit the application of our conceptual constructs. We realize, however, that all scientific laws merely represent abstractions and idealizations expressing certain aspects of reality.

started with a general definition of “system” defined as “a set of elements in interaction” and expressed by the system of equations

Hence principles such as those of wholeness and sum, mechanization, hierarchic order, approach to steady states, equifinality, etc., may appear in quite different disciplines. The isomorphism found in different realms is based on the existence of general system principles, of a more or less well-developed “general system theory.”

there are analogies— i.e., superficial similarities of phenomena which correspond neither in their causal factors nor in their relevant laws.

homologies. Such are present when the efficient factors are different, but the respective laws are formally identical. Such homologies are of considerable importance as conceptual models in science. They are frequently applied in physics. Examples are the consideration of heat flow as a flow of a heat substance, the comparison of electrical flow with the flow of a fluid, in general the transfer of the originally hydrodynamic notion of gradient to electrical, chemical, etc., potentials. We know exactly, of course, that there is no “heat substance”

Analogies are scientifically worthless. Homologies, in contrast, often present valuable models, and therefore are widely applied in physics.

system theory should prove an important means in the process of developing new branches of knowledge into exact science—i.e., into systems of mathematical laws.

the question whether a hypothetico-deductive system embracing all sciences from physics to biology and sociology may ever be established. But we are certainly able to establish scientific laws for the different levels or strata of reality.

Reality, in the modern conception, appears as a tremendous hierarchical order of organized entities, leading, in a superposition of many levels, from physical and chemical to biological and sociological systems. Unity of Science is granted, not by a utopian reduction of all sciences to physics and chemistry, but by the structural uniformities of the different levels of reality.

The organismic conception does not mean a unilateral dominance of biological conceptions. When emphasizing general structural isomorphies of different levels, it asserts, at the same time, their autonomy and possession of specific laws.

In modern science, dynamic interaction appears to be the central problem in all fields of reality. Its general principles are to be defined by system theory.

organismic viewpoint. In one brief sentence, it means that organisms are organized things and, as biologists, we have to find out about it.

Classical science was essentially concerned with two-variable problems, one-way causal trains, one cause and one effect, or with few variables at the most. The classical example is mechanics.

The various “systems theories” also are models that mirror different aspects. They are not mutually exclusive and are often combined in application. For example, certain phenomena may be amenable to scientific exploration by way of cybernetics, others by way of general system theory in the narrower sense; or even in the same phenomenon, certain aspects may be describable in the one or the other way.

If the intuitive approach leaves much to be desired in logical rigor and completeness, the deductive approach faces the difficulty of whether the fundamental terms are correctly chosen. This is not a particular fault of the theory or of the workers concerned but a rather common phenomenon in the history of science;

The danger, in both approaches, is to consider too early the theoretical model as being closed and definitive—a danger particularly important in a field like general systems which is still groping to find its correct foundations.

The “Copernican Revolution” was more than the possibility somewhat better to calculate the movement of the planets; general relativity more than an explanation of a very small number of recalcitrant phenomena in physics; Darwinism more than a hypothetical answer to zoological problems; it was the changes in the general frame of reference that mattered

Dynamic ecology, i.e., the succession and climax of plant populations, is a much-cultivated field which, however, shows a tendency to slide into verbalism and terminological debate.

“All theories of behavior are pretty poor theories and all of them leave much to be desired in the way of scientific proof”—this being said in a textbook of nearly 600 pages on “Theories of Personality.”

The notions of “equilibrium,” “homeostasis,” “feedback,” “stress,” etc., are no less of technologic or physiological origin but more or less successfully applied to psychological phenomena. System theorists agree that the concept of “system” is not limited to material entities but can be applied to any “whole” consisting of interacting “components.”

Every mathematical model is an oversimplification, and it remains questionable whether it strips actual events to the bones or cuts away vital parts of their anatomy.