The physical sciences of humanity are fast approaching the goal of an integrated mathematical theory of the inanimate cosmos. Unfortunately our biological sciences remain a hodge-podge collection of partial theories at present, and our behavioral, social, and political sciences lag still further behind. But the recent emergence of a comprehensive "systems" framework offers the bright promise of a patterned ed mosaic of knowledge that explains and relates together the porcesses inherent in all living things. Systems scientists today are attempting to construct a general living systems theory embracing all aspects of life on Earth from cells to societies.

What, exactly, is a "system"? Webster's Unabridged defines it simply as "a set or arrangement of things so related or connected as to form a unity or organic whole." While this is certainly suggestive, scientists prefer more precise terminology, as for example: "A system is a nonrandom accumulation of matter-energy, in a region of physical space-time, which is organized into interacting interrelated subsystems or components."

Examples of systems are all around us. The car we drive to work is a mechanical system. The human body is an organism system. The United Nations is a supranational system. Livers and eyeballs are organ systems. General Motors is a corporate organizational system. A bacterium is a cellular system. The Milky Way galaxy is a gravitational system.

What is not a system? Any set of subsystems or physical components which do not interact, or which do not have relationships in terms of the variables under consideration, is not a concrete system. Physicists call it a "heap." Again, examples abound. My stomach and your spleen, taken together, are not a system. Neither are the cells in your hand and the cells in your leather wallet. At another level, all the coal miners in Appalachia were not a concrete system until they were organized into an interacting, intercommunicating trade union.

General systems theory consists of a set of related definitions, assumptions, and propositions dealing with reality as an integrated hierarchy of organizations of matter and energy. But general living systems theory is concerned solely with a special subset of all systems in the universe—the living ones. To understand what "living "means, we must first take a look at the concepts of matter-energy and information. Why? Because all living systems known to Earthly scientists are made of matter and energy organized by information.

Matter is anything that has mass and occupies space. Energy is formally defined in physics as the ability to do work. According to the principle of conservation of energy, energy can be neither created nor destroyed. However, it may be changed from one form into another form, including the energy equivalent of rest mass. Matter may have kinetic energy (the energy of motion), potential energy (stored energy), and rest mass energy, which arises from the fact that mass and energy are equivalent. Either may be converted into the other according to Einstein's famous E = mc2 (rest mass energy equals mass multiplied by the speed of light squared).

All living systems need matter-energy in adequate amounts: Heat, light, water, minerals, fuels, steel, foodstuffs, and other raw materials. Energy to power the many processes of life usually comes from the breakdown of molecules (sugars, proteins, coal, gasoline), but occasionally also from the breakdown of atoms (nuclear power plants in certain modern societal systems). Apparently living systems at all levels must have subsystems or components which process the necessary matter-energy.

The patterning of matter-energy is information. The greater the complexity of any Hving system, the more information is required to describe it.

Information, like mass and energy, may be measured quantitatively. Communications engineers commonly define it as the logarithm to the base 2 of the number of alternate patterns, forms, organizations, or messages. (NOTE: When mx = y, x is called the logarithm of y to the base m.) The fundamental unit of information is the binary digit, or "bit." One bit is that amount of information which is necessary to answer a question having two equally likely alternatives. For instance, a secretly chosen letter of the English alphabet may be guessed by asking as few as five yes/no questions. Thus we say that a single letter represents five bits of information. Correspondingly, a five-letter word represents 5×5 = 25 bits of information, a 50,000-word book 25×50,000 = 1,250,000 bits, and so forth.

All living systems need information in varying amounts. Information on how to reproduce is found in the genetic DNA template in all living cells. The pancreas (a human body organ system) needs data on blood sugar levels in order to produce the correct amounts of natural insulin. Individual organisms need information about the local environment (provided by eyes, ears, and other means) in order to survive. Companies require market data, R&D research, and legal advice to compete successfully; societies need town meetings, newspapers, and elections to remain healthy. Living systems at all levels must have subsystems which process information.

It is important to bear in mind that there is no principle of conservation of information analogous to the concept of matter-energy conservation. Total information can always be decreased in any physical system without increasing it elsewhere. Surprisingly enough, however, information can be increased by decreasing it somewhere else by a larger amount. All living systems, from cells to societies, perform this subtle magic. How can they do this?

A "closed" system has impermeable boundaries through which no matter-energy or information may pass. According to the Second Law of Thermodynamics, randomness and disorder (entropy) in any closed system must always increase. Patterned structures must degrade irrevocably over time—a log burned in a sealed container cannot be unburned. Any organized matter-energy trapped within a closed system gradually becomes disordered and tends toward a final state of maximum randomness. Information then is progressively destroyed.

"Open" systems, on the other hand, have boundaries at least partially permeable to external sources of matter-energy and information. The Second Law permits information in open systems to increase, decrease, or stay the same.

Perhaps the most important characteristic of living systems is that they are open systems, functioning constantly to avoid the loss of information and complexity. This they do by ingesting inputs of food, fuels, or other forms of matter-energy which are higher in complexity than their outputs. That is, by consuming ordered materials and excreting lessordered materials, living systems can absorb patterning and information from external sources and thus maintain internal complexity against the natural randomizing forces of nature.

In other words, living systems convert order in their surroundings into disorder, and thereby increase their own internal order. This is the essential process of life.

THE GENERAL THEORY

Dr. James Grier Miller, pioneer in systems science and president of the University of Louisville in Kentucky, is largely responsible for developing what is the most comprehensive and far-reaching general living systems theory devised to date. In his fascinating 1100-page monograph entitled Living Systems (McGraw-Hill, N.Y.; 1978), Miller assembles an incredibly diverse multidisciplinary compilation of facts, figures, researches and ideas, and blends them smoothly into a single coherent unity.

According to Dr. Miller, the universe is comprised of a natural hierarchy of systems. Each system is more complex than the last and is buih up from simpler systems. For example, atoms are composed of particles; molecules are made of atoms; crystals and organelles are constructed with molecular and atomic building blocks. The subset of living systems begins just above the level of crystallizing viruses such as the tobacco mosaic variety. Since viruses are necessarily parasitic upon cells for their existence, they are not considered to be alive by most biologists.

Above the virus there are seven hierarchical levels of living systems. Cells (a single cell in your body, or in any animal or plant on Earth), are at the simplest level, composed of atoms, molecules, and multimolecular organelles. At the next level is the organ (your heart, liver, brain), made up of cells aggregated into tissues. Then there is the level of organism (you, your dog, a fruit fly, a tree), with organs, tissues and organelles. At the fourth level there are groups (herds, flocks, forests, families, teams, committees, tribes), of organisms. Next is the organization (cities, hospitals, corporations, universities), comprised of groups and individual organisms. Then there is the society or nation, made up of organizations, groups, and individuals; and finally supranational systems (United Nations, European Economic Community, NATO), composed of societies and organizations.

By itself, the idea of hierarchical levels is not terribly exciting. What is exciting is that, according to Miller's theory, the same 19 critical subsystems may be found in every living system, at each of the seven basic levels of life activity!

TABLE 1 Subsystems which process both matter-energy and information 1. Reproducer, the subsystem which carries out the instructions in the genetic information or charter of a system and mobilizes matter, energy, and information to produce on or more similar systems. Please note it is intended to reproduce the entire system, not create replacement for individual components of the system.

Example: the charter of a group. 2. Boundary, the subsystem at the perimeter of a system that holds together the components which make up the system, protects them from environmental stresses, and excludes or permits entry to various sorts of matter-energy and information.

Example: A cell wall. Guards patrolling the fences and gates of an organization's property. Subsystems which process matter-energy Subsystems which process information 3. Ingestor, the subsystem which brings matter-energy across the system boundary from the environment.

Example: an organization's procurement or receiving departments. 11. Input Transducer, the sensory subsystem which brings markers bearing information into the system, changing them to other matter-energy forms suitable for transmission within it (e.g., writing a phone conversation down on paper).

Example: military scouts, telephone operators, personnel distributing mail, intelligence gathering units. 12. Internal Transducer, the sensory subsystem which receives, from subsystems or components within the system, markers bearing information about significant alterations in those subsystems or components, changing them to other matter-energy forms of a sort which can be transmitted within it.

Example: group ombudsman or sensor of group changes, internal inspection or auditing unit in an organization. 4. Distributor, the subsystem which carries inputs from outside the system or outputs from its subsystems around the system to each component.

Example: an organization's truck drivers and supply clerks. 13. Channel and Net, the subsystem composed of a single route in physical space or multiple interconnected routes over which markers bearing information are transmitted to all parts of the system.

Example: talking, telephones, radio. 14. Timer, the subsystem which transmits to the decider information about time-related states of the environment or of components of the system. This information signals the decider of the system or deciders of subsystems to start, stop, alter the rate, or advance or delay the phase of one or more of the system's processes, thus coordinating them in time. 5. Converter, the subsystem which changes certain inputs to the system into forms more useful for the special processes of that particular system.

Example: an organizations subsidiary groups operating oil refineries, electric generating plants, slaughter houses, etc. 15. Decoder, the subsystem which alters the code of information input into it through the input transducer or internal transducer into a "private" code that can be used internally by the system.

Example: language translation teams, deciphering secret messages, interpreting intelligence data, interpreting directives and regulations. 6. Producer, the subsystem which forms stable associations that endure for significant periods among matter-energy inputs to the system or outputs from its converter, the materials synthesized being for growth, damage repair, or replacement of components of the system, or for providing energy for moving or constituting the system's outputs of products or information markers to its subsystems.

Example: components involved in the cooking of food, factory production, maintenance and repair of equipment, building construction. 16. Associator, the subsystem which carries out the first stage of the learning process, forming enduring associations among items of information in the system. Information can come from input transducer, internal transducer, or memory.

Example: scientists 7. Matter-Energy Storage, the subsystem which places matter or energy at some location in the system, retains it over time, and retrieves it.

Example: refrigerators, lockers, stock rooms, fuel storage tanks. 17. Memory, the subsystem which carries out the second stage of the learning process, storing information in the system for different periods of time, and then retrieving it.

Example: filing sections, librarians, computer operators. 18. Decider, the executive subsystem which receives information inputs from all other subsystems and transmits to them outputs for guidance, coordination, and control of the system. This is the only subsystem that cannot be "dispersed" to another system above or below this system. It can be laterally dispersed i.e., decision making can be decentralized.

Example: group leader, headquarters or executive office of an organization. 19. Encoder, the subsystem which alters the code of information input to it from other information processing subsystems, from a "private" code used internally by the system into a "public" code which can be interpreted by other systems in its environment.

Example: speech writers, lobbyists, advertising departments. 8. Extruder, the subsystem which transmits matter-energy out of the system in the form of products or wastes.

Example: cleaning crews, sewage disposal units, delivery trucks and drivers, crews manning trains, barges, or other delivery systems. 20. Output Transducer, the subsystem which puts out markers bearing information from the system, changing markers within the system into other matter-energy forms which can be transmitted over channels in the system's environment.

Example: radio operators, public relations departments, news-releasing agencies. 9. Motor, the subsystem which moves the system or parts of it in relation to part or all of its environment or moves components of its environment in relationship to each other.

Example: moving crews, car pools. 10. Supporter, the subsystem which maintains the proper spacial relationships among components of the system, so that they can interact without weighting each other down or crowding each other.

Example: building managers and designers, walls, tables, chairs.

What are these nineteen critical subsystems? As shown in Table 1, there are eight subsystems which process only matter-energy, nine subsystems which process only information, and two subsystems which process both matter-energy and information. Dr. Miller claims that every living system must perform the same nineteen basic functions to stay alive. If any one subsystem is blocked or destroyed, the system eventually dies.

At the top of Table 1 are the two critical subsystems that process matter-energy and information simultaneously. The first of these is the reproducer, capable of giving rise to other systems similar to the one it is in. This is a unique function, since it is critical only to the survival of the class of system or species involved and not to the system or individual itself. (Living systems often continue to exist even though they cannot reproduce—worker bees, mules, and so forth.) Reproduction, involving the transmission of a genetic template, blueprint, or charter to succeeding generations, seems mainly to be an information transmission process. Yet the matter-energy necessary to physically construct the next generation must also be processed by the reproducer.

The boundary, like the reproducer, serves a dual function. This subsystem, located at the system perimeter, controls the flow of matterenergy and information into and out of the system. It also holds together the other components that comprise the system and protects them from environmental stresses and traumas.

Farther down in Table 1 are two parallel columns, identifying those critical subsystems which process either matter-energy or information, but not both. Entries appearing opposite one another perform functions with important similarities. (For instance, the "distributor" does for matter-energy approximately what the "channel and net" does for information.)

The first matter-energy processing subsystem is the ingestor, responsible for bringing raw materials and energy from the environment across the system boundary.

Next, the distributor carries inputs from outside or outputs from internal subsystems around the system to each component.

The convertor changes certain inputs to the system into forms more useful for the special processes within that particular system.

The producer, using matter-energy inputs to the system directly or outputs from the convertor, builds up stable aggregations of matter capable of enduring for long periods of time. These synthesized materials are used for growth, damage repair, replacement of worn or obsolete components, production of the system's output of products, providing energy for physical motion, or for creating information "markers" for use in communication with the external environment. (Information, so far as we know, is always borne on a marker of matter-energy.)

The subsystem called matter-energy storage serves a warehousing function, retaining in the system for different periods of time deposits of various sorts of matter-energy.

The extruder transmits matterenergy out of the system in the form of finished products or wastes.

The motor subsystem moves the system or its parts relative to all or part of the external environment, or moves components of the environment itself in relation to each other.

Finally, the supporter maintains the proper spatial relationships among system components, allowing each to interact without interfering with or seriously crowding the others.

Like the matter-energy metabolism of all living systems, an information metabolism exists as well, consisting of nine principal components. By analogy to the sequence, of matterenergy subsystems discussed above, information metabolism includes inputs, internal processes, and outputs of various information signals.

The first information processing component is the input transducer, a sensory subsystem that brings information-laden markers into the system and changes them into other matter- energy forms more suitable for internal transmission.

The internal transducer serves a related function with regard to information markers originating within the system. It is a sensory subsystem that receives information from internal components of the system relating to significant changes in the status or condition of those components. The internal transducer then changes this data into other matter-energy forms capable of easy transmission throughout the corpus of the system.

Channel and net is the subsystem comprising a route or routes in physical space by which markers bearing information are transmitted to all parts of the system.

(ed note: after this article was written, they added the "timer" subsystem)

The decoder accepts data from either the input transducer or the internal transducer in a "public" code and converts the information into a "private" code more easily understood by other internal components.

The associator carries out the first stage of the learning process, by forming enduring associations among items of information within the system.

The memory carries out the second stage of the learning process. Various sorts of information are stored in the system for different periods of time. Data generally remain in memory and can be retrieved upon demand, until replaced by new data or until misplaced, garbled or destroyed by the normal disordering and randomizing processes that occur in all physical systems over time.

The decider is the executive subsystem which receives information inputs from all other subsystems and transmits to them information outputs that control the entire system. The decider is the "boss." It makes choices among alternatives; that is, its input always contains more alternatives or patterns or "degrees of freedom" than its output. The decider is the only absolutely essential subsystem, because a system cannot be parasitic upon or symbiotic with Emother system for its deciding.

The encoder alters the "private" code of internal transmissions back into a "public" code that can be interpreted by other systems in the environment. Encoders and decoders thus serve reciprocal functions, although they operate on different data.

Finally there is the output transducer, the subsystem that changes information markers within the system into other matter-energy forms which can be transmitted over external channels in the environment, and then emits these markers from the system.

Table 2, provided by Miller, is of great value in visualizing how the 19 critical subsystems relate to reality. In the table there are 19 rows, representing each important subsystem, and seven columns, for each of the hierarchical levels of hving systems. The progress of modern science is such that all but seven of the 133 spaces in Table 2 can be filled in with concrete, physical examples. In those seven special cases, however, there is evidence that the processes in question are being carried out somehow. These gaps. Miller says, "constitute challenges for further basic research."

TABLE 2

Selected Major Components of Each of the 19 Critical Subsystems at Each of the Seven Levels of Living Systems LEVEL SUBSYSTEM Cell Organ Organism Group Organization Society Supranational System Reproducer 3.1.1 Chromosome None (downwardly dispersed to cell level) Genitalia Mating Dyad Group that produces a charter for an organization Constitutional Convention Superanational systems which creates another supranational system Boundary 3.1.2 Cell membrane Capsule of viscus Skin Sergeant at arms Guard of an organization's property Organization of border guards Supranational organization of border guards Ingestor 3.2.1 Gap in cell membrane Input artery of organ Mouth Refreshment chairman Receiving department Import company Supranational system officials who operate international ports Distributor 3.2.2 Endoplasmic reticulum Blood vessels of organ Vascular system Mother who passes out food to family Driver Transportation company United Nations Childrens Fund (UNICEF) which distributes food to needy children Converter 3.2.3 Enzyme in mitochondrion Parenchymal cell Upper gastrointestinal tract Butcher Oil refinery operating group Oil refinerty European Atomic Energy Community (EURATOM) concerned with the conversion of atomic energy Producer 3.2.4 >Enzyme in mitochondrion Parenchymal cell UNKNOWN Cook Factory production unit Factory World Health Organization (WHO) Matter-energy storage 3.2.5 Adenosine triphosphate (ATP) Intercellular fluid Fatty tissues Family member who stores food Stock-room operating group Warehouse company International Red Cross, which stores materials for disaster relief Extruder 3.2.6 Gap in cell membrane Output vein of organ Urethra Cleaning operative Delivery department Export company Component of the International Atomic Energy Agency (IAEA) concerned with waste extrusion Motor 3.2.7 Microtubule Muscle tissue of organ Muscles of legs None (laterally dispersed to all members of group who move jointly) Crew of machine that moves organization personnel Trucking company Transport component of the North Atlantic Treaty Organization (NATO) Supporter 3.2.8 Microtubule Stroma Skeleton Person who physically supports others in group Group that operates organization's building National officials who operate public buildings and land Supranational officials who operate United Nations buildings and land

CROSS-LEVEL HYPOTHESIS

General living systems theory is an evolutionary theory. The general direction of evolution has been to produce systems with greater complexity of organization, packed with more and more information. Miller explains this by using what he calls the evolutionary principle of "shredout," a sort of systemic division of labor. In this division, each process is broken down into multiple subprocesses, redistributed over multiple physical structures, each of which becomes specialized for carrying out a particular subprocess. It is, as Dr. Miller suggests, "as if each strand of a many-stranded rope had unraveled progressively into more and more pieces."

Consider a population of primordial living cells, each having all 19 critical subsystems. As mutations occurred in the original cells, the mutant entities continued to live only if they were still able to perform all nineteen critical processes. Those mutants that could not were ruthlessly eliminated by natural selection; those that could survived to reproduce more of their own kind.

As more complex cells evolved, more complicated subsystems emerged—but always the same basic 19 processes had to be performed. As cells gave rise to higher systems at more advanced levels—organs, organisms, and so forth—their subsystems "shredded out" into increasingly sophisticated units carrying out more complex and often more effective versions of the nineteen processes. Each of the critical subsystems was essential for the survival of every living system at every point in this evolution. If any one of these subsystems had ceased to function even briefly, the system it was in soon would have ceased to exist. So evolution didn't eliminate any of the subsystems, and each of the nineteen are found today at every level from cell to supranational system. This basic principle of evolutionary unity makes it possible to derive valid cross-level generalizations in the study of living systems.

Systems scientists normally concern themselves with confirming or disproving a hypothesis relevant to a single critical subsystem or to some other specific aspect of a single system. Tests are conducted on only one type of system at one level. But in the "general systems" paradigm, the proposition will next be tested on other types of systems at the same level, and later on systems at different levels, using the same variables and dimensional units of measurement. Some hypotheses may be found valid at all levels of living systems; others may apply only to a few levels.

Dr. Miller lists nearly two hundred cross-level hypotheses of possibly general validity. Most of them have been discovered on one particular hierarchical level, and have then been tentatively extended and at least cursorily checked at two or more different levels. I cannot possibly list and discuss all of Miller's propositions here, but a few of my favorites include the following:

Hypothesis 3.3-1: Up to a maximum higher than yet obtained in any living system but less than one-hundred percent, the larger the percentage of all matter-energy input that it consumes in information processing controlling its various system processes, as opposed to matter-energy processing, the more likely the system is to survive.

In other words, a system cannot be "too smart." It is probably true that more complex species devote a larger fraction of their total cell mass to information processing than lower species, and no one has yet discovered a species that failed to survive because too much of its body was neural tissue. Modern organizations and advanced societies are committing continually higher percentages of their available matter-energy to the communications media and other forms of information processing, vastly more than "primitive" societies do.

Hypothesis 3.3.7.2-14: A system which survives generally decides to employ the least costly adjustment to a threat or a strain produced by a stress first and increasingly more costly ones later.

This is a restatement of the principle of least effort. Amoebas, for example, will eat nearby food first before swimming to engulf more distant morsels. Artificially-increased acidity in a dog's bloodstream will be compensated first by hyperventilation or "overbreathing" (an attempt to produce alkalosis), and if this does not work, then by increasing the rate of chloride excretion into the urine (a more complicated adjustment). When goals are frustrated, people resort first to goal-shifting, then to rationalization, then repression, and finally psychosis if all else fails. An army, in order to repel an attack, may sacrifice first a squad, then companies of regiments, and finally, if still unsuccessfull, entire divisions may be thrown into battle.

Hypothesis 3.3.7.2-18: Systems which survive make decisions enabling them to perform at an optimum efficiency for maximum physical power output, which is always less than maximum efficiency.

In other words, surviving systems are designed for peak loads, not normal loads. The most efficient system survives only if it can also put out maximum physical power when needed, especially in combat or competitive situations. The "fight-or-flight" response of many animals diverts blood from the gut to the extremities, enhancing fighting energy and providing faster clotting to seal wounds. The cooks in an army under attack are allowed to leave their camp stoves and pick up rifles to participate in a maximum defensive effort to preserve the organization. In wartime, a society may conscript soldiers, increase taxes, commandeer vehicles and living quarters, and divert industry to the production of specialized war material.

Hypothesis 5.2-8: A system usually associates with other systems which have arisen from similar templates rather than with those derived from dissimilar templates.

That is, "birds of a feather flock together." There are many examples at all levels of living systems. When different types of embryonic cells are mixed together randomly, they sort themselves out and grow together only with other cells of the same type. Organ transplants tend to be rejected by the receiving organism. Family members often keep non-members out of personal relationships. Ethnics arriving in the United States for the first time tend to live near others of the same ethnic group. Companies doing business in similar fields meet in conventions among themselves more often than they meet with other types of companies. Nations of comparable origin and heritage tend to vote together in the United Nations.

Hypothesis 5.2-13: Under threat or stress, a system that survives, in the common good of total system survival, temporarily subordinates conflicts among subsystems or components until the threat or stress is relieved, when internal conflicts recur.

In other words, external threats unite warring factions. If a man and wife are having an argument and a well-meaning neighbor tries to intervene, the pair will temporarily suspend their differences and join in the ejection of the interloper. Public opinion is less likely to support an employee strike in organizations that provide essential services (hospitals, police, fire departments) than in organizations providing less-essential services. During war-time or periods of national disaster, societal, economic and social differences are often submerged in an attempt to meet the common threat—or the society may not survive. Supranational systems may close ranks in the face of a perceived threat to global stability, as for example the United Nations peacekeeping forces stationed in and around the Middle East and elsewhere.

APPLICATIONS

At this point, the reader may be wondering: "Fine, but can the dog hunt?" To be useful, any theory must generate concrete results. While full experimental investigation of his hypotheses remains a task for the future. Dr. Miller believes that living systems theory is more than a mere collection of truisms. The tremendous power of the theory derives from its broad and general apphcability, which manifests itself in two distinct ways.

First, the theory permits different systems within the same level to be compared directly and quantitatively. Examples might include comparisons of organismic memory subsystem function in unrelated animal species to uncover new principles of neurological evolution, or of the informational bit rates through the channel and net subsystems of democratic, oligarchic, and totalitarian societies to discover broad new principles of efficient operation applicable to any governmental organization. To the detriment of science such relationships rarely have been paid much serious attention by mainline scientists. By encouraging generalizations within a given hierarchical level, general living systems theory demands an ecological and holistic worldview of its practitioners. One early and controversial result of this kind of approach was the World III Model devised by the Club of Rome group at MIT. The purpose was to try to predict overall limits to growth of human society on Earth. Though admittedly a gross oversimplification of reality, the Model attempts to take account of the many different interactions among global system components—including population, capital, food, nonrenewable resources, and pollution.

Second, Miller's living systems theory is "general" inasmuch as it adopts a predominantly cross-level approach. This is immediately useful in a number of ways. In addition to the unification of diverse scientific and technical disciplines, the theory can help to identify unstudied variables and to illuminate gaps in existing knowledge. We recall the holes in Mendeleyev's Periodic Table of the Chemical Elements (first drawn in 1869) which predicted the discovery of the then-unknown elements germanium, galHum, scandium, etc. Similarly, the boxes in Table 2 marked "unknown" suggest gaps in current biological knowledge that may be remedied by further research.

Equally important, the theory promotes cross-level intellectual fertilization. Generalizations established at one level may be transplanted to others. Discoveries at the level of the cell or organ may foreshadow comparable results in studies of organizations or societies. It is virtually certain that the pace of scientific progress would quicken if the general systems approach were more widely adopted.

Many times in the past, qualitatively similar phenomena have been rediscovered at several different levels but the traditional rigid insularity of the academic disciplines forestalled any possibility of idea-transfer between levels. For example, B. F. Skinner's work on operant conditioning was done on whole organisms—humans, pigeons, rats and the like. Skinner then suggested, in his novel Walden II, that this mode of learning might be extended to societies as well. And, in the last decade, biofeedback researchers have discovered that the "behavior" of mternal organs likewise may be "conditioned." The astute general living systems theorist immediately will pause to consider whether Skinner's basic idea also might be applicable at the levels of the cell, the group, the organization, and the supranational system. Why wait for workers at each level independently to rediscover the same process?

The general systems approach also permits quantitative analysis. The same variables may be used to describe systems at different levels. For instance, a researcher may wish to evaluate a hypothesis concerning the matter-energy storage subsystem at all levels of human living systems, say, in Italy. A relevant system variable is rate of energy usage, which the researcher may determine as follows: human neuron (cell), 3 × lO-9 watts; human brain (organ), 30 watts; human body (organism), 150 watts; Italian steel factory (organization), 107 watts; the nation of Italy (society), 3 × 107 watts; and NATO (supranational system), 3 × 1012 watts.

Dr. Miller himself has experimentally examined several cross-level hypotheses suggested by the general theory of living systems. His personal interest lies in the processes of the channel and net subsystem and the problems of information overload and underload in living systems. Drawing on his earlier investigations of individual neuron response to data input overloads, and applying the systems approach, Miller formulated the following two cross-level hypotheses:

Hypothesis 5.1-1: As the information input to a single channel of a living system—measured in bits per second—increases, the information output—measured similarly—increases almost identically at first but gradually falls behind as it approaches a certain output rate, the channel capacity, which cannot be exceeded in the channel. The output then levels off at that rate, and finally, as the information input rate continues to go up, the output decreases gradually to ward zero as breakdown or the confusional state occurs under overload;

and

Hypothesis 5.1-25: Channels in living systems at higher levels in general have lower capacities than those in living systems at lower levels.

Miller set out to verify or disprove his hypotheses. First he checked the published literature at each level and found surprisingly strong support. Encouraged, he returned to the laboratory and set up a number of experiments designed to test the two hypotheses at the five levels of cell, organ, organism, group and organization. (It's hard to perform controlled tests on whole societies and supranational systems.) At each level, the response of the channel and net subsystem to a variety of information input rates was measured and recorded. The median maximum transmission rates per channel were found to be as follows: 4000 bits/sec for the cell, 55 bits/sec for the organ, 4.75-5.75 bits/sec for the organism, 3.44-4.60 bits/sec for the group, and 2.89-4.55 bits/sec for the organization.

These results support the hypotheses. By extending his knowledge of nerve cell behavior to other levels, Miller has discovered what may well be a general property of all living systems: When information input rate goes up, output rate increases to a maximum and then decreases, showing signs of overload. Apparently cells, organs, organisms, groups and organizations each react to data overloads in much the same way, with lower maximum bit rates at higher levels of living systems. Organizations as a whole can process more information than groups or individuals because they can use multiple channels.

The general theory should be widely applicable to many areas of human endeavor and to the solution of innumerable specific human problems. Cross-level hypotheses and multilevel concepts will permit advances in such diverse fields as pharmacology, human and veterinary medicine, applied botany and agriculture, biochemistry, biophysics and bionics, psychiatry, applied psychology, group psychotherapy and group dynamics.

At the level of the organization applications may include operations research on governmental agencies, transportation and communication services, corporate and factory efficiency, agronomics, education and health and justice delivery systems, and library and other information retrieval systems. At the national level, living systems theory can organize thinking and suggest solutions to problems in population control and family planning, energy crises, pollution control, resource allocation, industrial systems and economic cycles, and in military and environmental planning. The work on supranational systems, drawing lessons from lower hierarchical levels, can begin to address key questions in international law, integration of global services (World Health Organization, Universal Postal Union, UNESCO, and so forth), world economic planning, international relations and political stability, and the conduct or avoidance of global war.

There are also a number of highly speculative applications of Miller's theory. For instance, computer scientists should find it much easier to design and construct a thinking machine, working backwards from a theory of living systems. Research into the fundamental subsystems of the human brain will provide a model upon which artificial intelligence specialists may someday build an electronic intellect to act in the capacity of the "decider" subsystem in a fully-integrated and sophisticated mechanical android body.

Another possibility is the prospect of a science of psychohistory as envisioned by Isaac Asimov in his Foundation Trilogy classic. When a mature systems science unites biology, ethology, psychology, sociology, organizational dynamics and political science, then prediction of the future course of human civilization may become a reality. It may also be feasible to redesign entire organizational and societal systems to comply with precise specifications of stability, efficiency, longevity, growth, or even specific moral, ethical, or religious standards.

Miller's theory may also be relevant to our search for aUen civilizations located elsewhere in the universe. There could exist at least three higher levels of sentient organization beyond Miller's nominal seven: Interplanetary society, interstellar community, and galactic civilization. If the general theory of living systems is directly applicable at these higher levels too, it may be possible to make some reasonable guesses as to the sociological, cultural, and governmental forms that might be chosen by highly advanced extraterrestrials to organize their farflung interstellar empires.