International Encyclopedia of Systems and Cybernetics

A general theory of living systems has been established by J.G. MILLER, who introduces it in global terms as follows: The general living systems theory… is a conceptual system concerned primeraly with concrete systems which exist in space-time. Complex structures which carry out living processes I believe can be identified at seven hierarchical levels… cell, organ, organism, group, organization, Society, and supranational systems. My central thesis is that systems at all these levels are open systems composed of subsystems which process inputs, throughputs and outputs of various forms of matter, energy and information".(1978, p.1).

At the time, MILLER thus identified 7 levels and 19 critical subsystems. More recently J. and J.G. MILLER completed this taxonomy by interposing the "community", as a supplementary level in-between the organization and the society levels and, on the other hand, one more subsystem, the "timer", which introduces a general dynamics which seemed to be lacking in the first presentation of the theory. (1992)

MILLER pursued in 1978: "I identify 19 critical subsystems… whose processes are essential for life, some of which process matter or energy, some of which process information, and some of which process all three" (1978, p.1)

According to MILLER in his more recent statement, any system at any of the 8 levels need the same 20 critical subsystems but: "The structure and processes of a given subsystem are more complex at a more advanced level than at the less advanced ones. This is explained by what I call the evolutionary principle of "shred out", a sort of division of labor (as the)… general direction of evolution is toward greater complexity" (p.1).

For each subsystem, MILLER identifies "about a dozen variables representing different aspects of its processes. It would be easy to identify more if one wanted an exhaustive list. Each of these variables can be measured at each of the levels, and the sorts of variations discovered can be compared across the levels" (p.4).

This feature leads MILLER to his cross-level hypothesis method aimed at discovering isomorphies between processes and/or structures at different levels.

MILLER also states that "Physiology, biochemistry, genetics, pharmacology, medicine, economics, political science, anthropology, sociology and psychology are all almost entirely relevant. Physical science and engineering also contribute. Logic, mathematics and statistics yield methods, models and simulations, including some involving the relatively new approaches of cybernetics and information theory" (p.4).

Consequently, MILLER's is a strongly integrated and all-embracing systems theory.

From a different viewpoint H. MATURANA states: "A living system is an inductive system and functions always in a predictive manner: what happened once will occur again. Its organization (genetic and otherwise) is conservative and repeats only that which works" (1970, as quoted in E.von GLASERSFELD, 1976, p.117).

In other words, it is said that biological systems become organizationally closed and thus autopoietic.

Still from another angle, A.S. IBERALL states: "… a living organism is a working thermodynamic engine during its entire life phase" (1973, p.4).

It is also a part of LOTKA's world engine.

It should however be noted that the living system is submitted, as shown principally by I. PRIGOGINE, to specific thermodynamic laws which allow it to organize itself in apparent contradiction with the 2d.law and to maintain itself as an island of organization during its whole life. The price is, however, an acceleration of the increase of entropy in the environment.

This is still more so for self-organizing human groups and societies, composed of living systems.

LIVING SYSTEMS: The 8 levels of complexity

J.G. MILLER defines a hierarchy of 8 basic types of living systems in order of growing complexity. Every level is made of elements of the immediately inferior levels of complexity. However, all of these are ordered in 20 critical subsystems, i.e. they are not merely unordered congeries.

The first three levels are biological: The cell, the organ and the organism.

The fourth, i.e. the group, is an ordered reunion of organisms, and intermediate between the biological and the (human) social level. MILLER did not consider the case of social insects or plant colonies.

The last four levels are social: The organization (e.g. an enterprise), the community (e.g. a town, or city), the society (a state) and the supranational system. (the numerous and more or less connected international agencies: U.N., UNESCO, UNEP, WHO, FAO, etc. (1993, p.158).

In his first versions of "Living systems" (1965, 1978), MILLER described only seven levels. The new level he introduced is the "community", mediatory between the organization and the society. His model for the supranational system was the European Community, as it was in 1978.

One wonders if the eighth level should not be the man-planet system, whose subsystems would be the various international organizations formerly mentioned, and others instances still to be created. Could the Internet not become for ex. the communication subsystem of the planetary system?

LIVING SYSTEMS: The 20 critical subsystems

See the complete listing under: "Subsystems" and each specific type of subsystem under the corresponding alphabetic listing.