Joël
de Rosnay
This is chapter 1 of the "The
Macroscope" by Joël
de Rosnay
Today the world is messages, codes, pieces of information. What dissection tomorrow will dislocate our objects in order to recompose them in a new space? What new Russian doll will emerge from it? --François Jacob
The atom, the molecule, the cell, the organism, and society fit one within the other like a series of Russian dolls. The largest of these dolls is the size of our planet, it contains the society of men and their economies the cities and industries that transform the world, the living organisms and the cells which comprise them. One could continue in this way to open successive dolls as far as the elementary particles, but let us stop here.
The purpose of this preliminary exploration is twofold. First it is a matter of providing a "primer" in ecology, economics, and biology-- disciplines that force us today to modify our ways of thinking. The three are not often united in a single approach--a situation that offers a risk but also an advantage. The risk is that you may find that the material dealing with the field you know best is too schematic, too simplistic. The advantage (which derives directly from the use of the macroscope) is that you will be able to discover, in other fields, new knowledge that may enrich and enlarge your own personal outlook.
Then it is a matter of introducing the concepts of "systems" and "systemic approach," the bases of the new culture of the concerned man of the twenty-first century. The opening of each doll exposes examples and practical aspects in advance of the general theory. (Remember, there is nothing to keep you from beginning with the second chapter, on systems, if you wish.)
All life on earth rests on the present or past functioning of the ecosystem, from the smallest bacteria to the deepest forests, from the fragile plankton of the oceans to man, his agriculture, and his industry. Thanks to the reserves of energy accumulated during the life of the world, the complex structures of society are maintained: large cities, industries, and communications networks.
The ecosystem is literally the house of life, and the science that studies it is ecology. This term was created in 1866 by the German biologist Ernst Haeckel from the Greek oikos, house, and logos, science. Ecology is concerned with the relations that exist between living beings and the milieu in which they live.
Yet the ecosystem is much more than merely the milieu in which one lives. In a way it is itself a living organism. Its giant cycles activate everything in the mineral world and the living world. Its biological power plants produce billions of tons of organic matter, matter that is stockpiled, distributed, consumed, recycled in the form of mineral elements, then reintroduced in the same factories, to be replenished with solar energy and to return through the cycles that maintain the life of every organization.
In what movements, what transformations does this "life" of the ecosystem manifest itself? It is shown in atmospheric circulation--winds the movement of the clouds, precipitation, everything that could be seen by studying the earth at a distance. It is manifested in the flow of water-- streams and rivers moving to the seas, the great ocean currents, the displacement of glaciers. It is seen in the movements of the earth's crust-- earthquakes, volcanos, erosion, sedimentation, and, over a sufficiently long period, the formation of mountain chains. Finally, there are the life cycles in which the basic materials of living beings are perpetually made, changed, and circulated.
All these movements, displacements, and transformations require energy. Whatever their nature or their diversity of being, they draw this energy from three principal sources: solar radiation, energy from the earth's core (seismic or thermal), and gravity. Solar radiation is by far the most important source of energy, for it represents 99 percent of the energy balance of our planet. Even energy furnished by fossil fuels is nothing more than solar energy in storage.
Solar energy, then, powers the cycles of the ecosystem. To set a machine in motion in order to produce work, energy must run from a hot source to a cold "sink"--where it disappears forever. In the case of the sun-and-earth system the hot source is the flux of solar energy (radiation of short wavelengths), the cold sink the space between the stars. That space directly absorbs heat reflected from the earth as well as heat produced by geological, biological, and industrial processes that take place on earth. This reflection dissipates energy; it disperses it, disorganizes it, renders it unusable in the production of work. Thus between the sun, the earth, and the "black depths" of the terrestrial environment there is an irreversible current, a waterfall of energy that flows from hot to cold.
In addition to the work produced on it (rapid movements and transformations), the earth holds its store of energy in equilibrium and consequently maintains its constant temperature through the radiation of heat toward space. It establishes a balance between energy received (energy used in the geological and biological processes) and energy broken down in irretrievable heat and irradiated toward space.[1] Only a negligible fraction of the immense quantity of solar energy received daily on the earth is used by living beings (Fig. 3).
The ecosystem is composed of four fields in strict interaction with one another: air, water, earth, and life. They are called respectively atmosphere, hydrosphere, lithosphere, and biosphere. The arrows in Figure 4 show that each field is related to all of the others. Even sediments on the floors of the oceans do not escape this rule; their composition depends not only on marine life and the composition of the oceans but also on the composition of the atmosphere.
The flow of energy that passes through the ecosystem is irreversible and inexhaustible. However, the chemical elements that make up all mineral or organic forms that we know on earth exist in finite number. These elements are found in the very heart of the ecosystem and are recycled after use. Everything that lives is made from building blocks that contain only six basic elements: carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulphur (S), and phosphate (P). The structures remain, but the elements of construction are replaced. Biologists call this dynamic renewal turnover. Living things (and the colonies they form--forests, populations, coral reefs) are continually being assembled and disassembled. Thus the ecosystem must have on hand a considerable stock of replacement parts to insure recycling (nothing, remember, is produced de novo) and must control everything by a system of regulation that avoids scarcities as well as excesses.
To understand the finite nature of the ecosystem, one might imagine a bottle containing water, air, rocks, and a thin film of life (Fig. 5). When exposed to the sun, the bottle becomes the seat of great activity. The sun's rays, striking it at different angles and in different spots, cause inequalities of temperature and convection currents that produce movements of the air and the water. (The same thing happens on earth: similar differences of temperature set in motion formidable masses of air and water and produce winds, rain, waves, and currents.)
If our bottle contains algae (simple one-cell plants capable of accomplishing photosynthesis) and protozoa (microscopic one-cell animals), the biological cycles can begin. The organic matter produced by the algae with the help of the sun's rays is "burned" by the protozoa. This combustion furnishes the energy that allows them, for example, to move about to look for food; it is made possible by the presence of oxygen released by the algae. And it is from carbon dioxide, the residue of the combustion, that the algae make organic material. The cycle is accomplished; all the elements in the bottle have been reused.
In the earth's ecosystem the elements essential to life are successively used and regenerated in the course of well-known cycles: the cycles of carbon, nitrogen, sulphur, and phosphate. These elements circulate among three huge reservoirs in which they are stockpiled: the reservoir of the atmosphere (and of the hydrosphere), the reservoir of the biomass (the mass of organic matter represented by all living beings), and the reservoir of sediments. Passing from one reservoir to another, the elements combine under different aspects: molecules of gas in the atmosphere, soluble ions (atoms that have lost or gained electrons) in the hydrosphere crystalized salt in the sediments, organic molecules in the reservoirs of life.
In the atmosphere elements appear as molecules of gas: nitrogen (N2), oxygen (O2), sulphur dioxide (SO2), and carbon dioxide (CO2). In the hydrosphere, in sediments or in the soil, they occur in the form of soluble ions or bound in the form of salts (carbonates, nitrates, sulfates, phosphates).
The organic stage of the ecological cycles (the reservoir of life) can be considered the "motor" of all the cycles. In the course of this stage the principal substances responsible for the maintenance of life are made and consumed. Here the amount of oxygen in the atmosphere is regulated and the billions of tons of materials are stored. All of this comes about through an organization that is a model of industry and economy, with production, stockpiling, distribution, consumption, equitable sharing of energy, and complete recycling of materials. The three groups of organisms on which this industry and this economy rest are the producers, the consumers, and the decomposers.
The producers are green plants, aquatic vegetation, and, more generally, all organisms capable of photosynthesis (the production of organic material solely from solar light and mineral carbon gas). Producers are also called autotrophs.
The consumers are animals of all sizes, herbivores and carnivores, in terrestrial and aquatic milieus. They feed on living organisms and, through an internal oxidation called respiration, burn the organic materials that compose the tissues of their prey. Consumers are also called heterotrophs.
The decomposers feed on dead organisms or chemical substances dispersed in the environment.
Figure 6 sums up the relationship between these three groups whose activity makes possible the functioning of the ecosystem and the regulation of its equilibrium.
During the day the producers manufacture great quantities of organic matter that accumulates in plant cells; at the same time there is an enormous output of oxygen. At night the process of oxidation takes over: the consumers oxidize (burn) the organic matter recently made and stored in order to produce the energy that allows them to perform work. This is the respiratory process. Of course animals, vegetation, and decomposers breathe during the day as well, but the animal processes of production are of such magnitude that they render virtually negligible the results of the oxidation that occurs simultaneously.
The two processes that form the basis of life, production and consumption (photosynthesis and respiration), are closely linked. An important difference exists between organisms capable of transforming radiant energy (light) and those that transform fixed energy, or energy trapped in the chemical combinations of organic molecules. Fixed energy is freed only when the combinations are broken. This happens during a free combustion (fire) or a controlled combustion (respiration).
Fixed energy then travels the length of the food chain (also called the trophic chain), which is made up of consumers (the herbivores and the various levels of carnivores). Each in turn profits to the maximum extent from the energy stored in the tissues of the organisms it captures-- organisms that precede it in the series. This energy is used to the last particle at the time of the decomposition of animal bodies and vegetation. Microorganisms extract energy from already relatively simple organic molecules by transforming them into mineral molecules that are recirculated in the ecosystem.
Whatever the transforming organism may be, energy is lost to the food chain in three different ways.
Figures 7 and 8 give some idea of the flow of energy in the food chain and the losses incurred there.
If the role of the plant-producers and the animal-consumers is generally well known, that of the microorganic decomposers is much less so. However, it is due to the latter's prodigious activity that organic wastes are transformed into substances that are stored in sediments protected from oxidation. They then take the form of soluble molecules transported by running water or that of gaseous molecules liberated in the atmosphere. Thus all forms can be used again by the ecosystem over varying lengths of time. What are the decomposers? They are bacteria, algae, fungi, yeast, protozoa, insects, mollusks, worms--a swarming population of minuscule beings with insatiable appetites. Organic molecules in excrement, urine, tissues in decomposition, and all degradable wastes are broken down by the decomposers into smaller and simpler fragments. This molecular breaking down leads, at the end of the series, to carbon dioxide and to water, the ultimate residue of the decomposition of organic material.
Complete decomposition is accomplished, for example, in the oxygen rich environment of a forest or in a soil aerated by insects or turned over by earthworms. Residue that cannot be broken down forms humus. The mineral elements, nitrogen, sulphur, and phosphate, are totally regenerated. During the process the decomposers themselves also breathe; they return carbon dioxide to the plants and release important quantities of heat. (This is readily apprehended in the vicinity of a pile of compost or manure.)
The breaking down of molecules can also be accomplished in the absence of oxygen--at the bottom of a lake, in the slime of swamps, inside a dead body. Here decomposition is incomplete and combustion proceeds slowly, liberating less energy; this is fermentation. Residues that are incompletely burned accumulate on the spot and give off the singular odor of decaying matter (as in marshes, for example). The organic matter of these very rich soils is incorporated into sediments little by little. This is the origin of peat, coal, and eventually petroleum.
The nitrates, sulfates, and phosphates incorporated in the sediments through the actions of decomposers can be freed by erosion--wind, frost, or rain--and are soluble in running water. They are reintroduced into the food chain at the roots of plants and will leave the network in the urine of animals (nitrogen) or in their excrement (sulphur and phosphate).
The recycling of living matter thus produces alternately an organic phase and an inorganic one: the sedimentary (storage in sediments) and the atmospheric (storage in the atmosphere). Because of this rotation and this linking of atmospheric, geological, and biological cycles, the major cycles that support the ecosystem are called biogeochemical cycles.
Figure 9 summarizes the principal phases of the general cycle of chemical
elements in the ecosystem (carbon, nitrogen, sulphur, and phosphate); it shows the circulation of chemical elements between the principal reservoirs. This diagram can be applied to each element, although certain cycles will have a predominant phase in the atmospheric reservoir or in the sedimentary reservoir.
The function of the ecosystem is not limited to the use of an irreversible flow of solar energy and to the cycles of production, storage, consumption, and regeneration of living matter. There is a third, equally important property: the regulation of the optimal functioning of the whole.
The biogeochemical cycles are self-regulating: a too extreme variation in one direction is immediately compensated by the modification of another variable, the overall effect of which is to return the system to its equilibrium. Each activity accomplished in the ecosystem has its counterpart.
Each interaction, each exchange, no matter how minimal, is potentially a regulatory mechanism. The general effect of these mechanisms maintains the community in a "dynamic balance." Along each food chain or cycle the flows of energy and material travel. These chains and cycles are interconnected, coordinated, and synchronized in the greater assembly that constitutes the biogeochemical cycles.The flow of materials continues from the producers to the consumers to the decomposers and between the different reservoirs without producing overabundance or shortage. The chemical composition of the great reservoirs of the atmosphere and the oceans is maintained within very strict limits. In this way the ecosystem resembles a living organism; it "knows" how to maintain the balance of its internal milieu.
How is regulation accomplished? The mineral or organic elements that pass from one group to another act as activators or inhibitors on the functioning of the global machine that produces or consumes. If one of the cycles should slow down, say because of the disappearance of certain consuming agents, the quantities in storage would grow rapidly. Since the speed of the flows of matter or energy that run in the cycles is proportionate to the quantities stored, the system balances itself by eliminating the overflow more rapidly.
The flow of water and the activity of animals play important roles in the mechanism of regulation. Water carries nutritive mineral elements to the roots of plants. Running water erodes sediments and accelerates their reentry into the cycles of the ecosystem. Evaporation and the transpiration of plants and animals are essential in the thermal regulation of organisms and in the control and maintenance of water vapor in the atmosphere.
The insatiable quest of animals for food, in the course of which they search for, catch, and consume other organisms, returns to the plants a regular stream of mineral substances in exchange for food. Thus the consumers work for the producers and producers work reciprocally for consumers. Each is "compensated" by the mineral elements or the food that the other group makes available to it. If the population of one kind of consumer increases too rapidly, the balance is upset, food becomes scarce, and individuals die of hunger--which reestablishes the optimum level of population for the setting in which this community lives.
The regulation of the size of a given population is based, then, on its struggle to obtain available food and on the mortality that strikes overabundant species through limited food sources. This regulatory mechanism is illustrated in Figure 10, the scheme of which I shall use often in the sections on economics and biology that follow.
Certain processes in the readjustment of equilibrium can be rapid, others extraordinarily slow. Ecologists have been able to measure, with the help of radioactive elements, the speed at which an element such as phosphate completes the organic cycle. They have seen how it passes from one organism to another, from chemical structure to chemical structure, from its entry into the food chain until its return to the mineral world. The complete period of the turnover (recycling) of phosphate, depending on the season, has actually been measured. In the case of a lake it ranges from ten minutes in summer to more than ten hours in winter; in the sedimentary stage the period of storage and liberation of phosphate can last two hundred years.
The three major reservoirs--the atmosphere, the hydrosphere, and the sediments--also play a regulatory role in the greater ecosystem by limiting the effects of sudden variations. They act as a buffer to reduce oscillations caused by cyclical variations. In this way the important concentration of carbonate ions in the ocean allows the almost constant concentration of carbon dioxide to be maintained in the atmosphere. Likewise, the interaction between atmosphere and sediments permits the regulation of the oxygen concentration in the atmosphere. This concentration has been maintained in a remarkable way at 21 percent for hundreds of millions of years (the rest of the atmosphere being 78 percent nitrogen and rare gases).
However, photosynthesis produces as many molecules of oxygen as respiration consumes.
How has oxygen been able to accumulate and remain at precisely 21% of the composition of the atmosphere? It maintains its position because a part of the organic matter made by photosynthesis is stored and protected from all oxidation in the deep-layered sediments. Stockpiling thus constitutes a particularly efficient way of regulating the amount of oxygen in the atmosphere.
Regulation also operates over much longer expanses of time. Through the movement of the plates that support the continents, ocean sediments can penetrate deeply into the materials that under intense heat will remake themselves into rock and volcanic gases. Moreover, the ocean trenches where sediments accumulate (called geosynclines) sink deeper and deeper under the weight of the sediments. In time the trenches will give birth to mountain ranges; the materials that they contain will be pushed violently toward the surface under the enormous pressures that they exert. With the help of erosion by wind and rain, mineral compounds that seemed to be lost to the ecosystem will return to it after millions of years.
Thus the regulatory mechanisms between the mineral world and the biosphere, with their very different response times that may take from a minute to millions of years, allow the ecosystem to maintain its structure and its overall functions.
In the ideal ecosystem that we have described so far, man is clearly missing. This new inhabitant of our planet has, by his agriculture, industry, and economy, modified little by little those equilibriums that existed long before him. Everything is happening as though a new organism (human society) were developing and growing from within the old. Man is like a parasite who takes energy and resources from his host and finally kills it.
How has man attained such power? He has no special instrument, but a number of means permit him to produce and distribute goods in constantly increasing quantities and on a larger and larger scale. It is the total of these means that constitutes the study of economics.
To study the general functioning of the economic machine through the macroscope one must adopt the outlook of a naturalist and observe from above the macroeconomic level. The economy is geared to the great ecological cycles--a fact that has long been forgotten or unrealized. When the economic machine accelerates or runs out of control, it consumes more energy, more material, more knowledge--and there will be more waste products dumped in the surrounding environment.
Such a point of view could lead to a naive interpretation of the economic machine if one did not keep in mind that behind the flows and cycles there are centers of decision. After all, it is in the midst of conflicts oppositions, arbitrations, the search for power, and the domination of one group by another that one must restore the functioning of the economic machine. Yet such an approach would be beyond the scope of this book; our concern is not to describe a particular economic system (system m the political sense) but rather to outline, as we did for the ecosystem, the dynamics of the whole, the general functioning of the economic machine, whatever the system to which it may belong.
The word economy draws its meaning from the same roots as the word ecology. Economy (oikos, house, and nomos, rule) means literally the rule of conduct of a home. By extension it denotes the art of correctly managing one's goods and, in a limited sense, of managing one's goods by avoiding useless expenses or by effecting savings.
From the home, economic activity has extended to the state (political economy) and to society as a whole. The economic function of human society, in the broad sense, becomes the production of goods for the satisfaction of man's needs. The scarcity of goods and the difficulties of their production result in limitations on their distribution and use. We come, then, to the famous definition of L. Robbins: "Economics is the study of human behavior as a relation between rare means and ends which have mutually exclusive uses."( see notes []).
This kind of definition diminishes economic functions as well as the role of man (producer and consumer), who is motivated, it would seem solely by the desire to satisfy his needs. Economics is then reduced, as François Perroux said, to a "science of means," the ends being the motives of morality and politics. One compares economics to the single function of a market where pure and perfect competition will reign. Homo economicus would appear to be a being without a soul, driven by rudimentary motives and barely capable of adapting passively to the "forces" of the market (René Passet)( see notes []).
This impoverishment of the economic function clearly appears in the classic diagrams of the economic cycles. They show a balance of forces between supply and demand, a flow of goods and services, a flow of money. Here is a machine that seems to be frozen, capable only of functioning by fits and starts, in an unreal universe from which nature is excluded (Fig. 11). The economic machine functions "between parentheses" without showing the irreversible flow of energy which inevitably breaks down in order to produce the work (see page 2 []).
Economy is also a "science of the living." To emphasize the close relationship between the ecosystem and the economic system, I should like to retrace, with the help of a series of diagrams, the brief history of the economy in its broadest sense. This is "the study of the mechanics of production, exchange, and consumption in a given social structure and the interdependencies between these mechanisms and this structure"(Attali and Guillaume)( see notes []).
The major stages in the development of the economic function coincide with the implementation of new powers that allow man to act more and more efficiently within his environment. Fire, agriculture, crafts and the perfection of tools, the steam engine, and the use of fossil fuels represent essential steps in the progress of man's domination of nature. All of these stages have not yet been experienced by the whole of humanity; the successive "economies" must therefore be considered as spread over time and coexisting in today's world.
The first stage is characterized by the conquest and mastery of fire. Man lives as a nomad, moving constantly in search of food and shelter. The essential function he assumes is to ensure his own survival. His main activity is to gather foods dispersed throughout his environment by hunting, fishing, and harvesting. In this way he obtains the calories that enable him to maintain his activity and assure his subsistence. Activities such as moving, fighting, and making an extended effort demand significant amounts of energy. Thus it is impossible for the nomadic hunter to maintain a sufficient reserve or "capital" of energy and skills with which he might speed his development (Fig. 12).
The second stage comes about with the "domestication" of solar energy through the development of agriculture and the domestication of animals, both important sources of energy. This stage, which first took place about ten thousand years ago, sees man settling in sheltered and fertile zones. He can now store grain, accumulate energy, and use his reserve of energy for other activities. He now produces, thanks to solar energy, the food supply that assures his survival, and he uses animal energy to run rudimentary machines and to move him about (Fig. 13).
The third stage witnesses the appearance of more perfect tools, the concentration of work in cities, and the advent of organizations and workshops that permit the large-scale development of the work of the artisan. The quantity and diversity of objects made by artisans become sufficiently great that manufactures serve as the basis for barter. One exchanges, according to carefully specified rules, this object for food, that animal for so many items. The laws of barter insure the balance between manufactured items and consumed products; this balance is accomplished through an intermediate zone of exchange, the market (Fig. l 4).
Since that time, man has not only assured his livelihood but engaged himself as creator and consumer of goods in a process of production, exchange, and consumption that involves many dimensions of his nature: art, the ability to use tools, the teaching of skills, pleasure in creation, and the accumulation of material goods.
The fourth stage is the preindustrial era. The tools perfected by the artisan made possible the manufacture of simple objects for precise needs. These tools are now replaced by machines, operated by the elements, human energy, or animal energy, which lead to an acceleration of the rates of production. The density of population and the potential for exchange found in urban concentrations make possible the division of work and the lengthening of the process of production. Thus the activities of various producers become intricately linked in the interdependent chains and networks that are needed to manufacture complicated objects step by step (Fig. 15).
The use of money on a large scale and the new forms of exchange that result drastically alter the economy. Money spreads out in space and time to affect work, barter, consumption, and savings. An hour of work performed in one place can be exchanged in another place, at a different moment, for money newly earned or long saved. The two great complementary flows on which the functioning of the economic machine is based now come into play, reinforcing and balancing each other. They are the flow of energy, materials, and information, which moves in one direction, and the flow of money (resulting from barter and transaction), which moves in the opposite direction.
The fifth stage, that of the modern industrial society, is characterized by massive use of fossil fuels (coal, oil, and gas). Other characteristics are the breaking up of work into a multitude of simple tasks which are generally without creative value, and the massive production of waste not recyclable by the ecosystem. The division of work, necessary to efficiency, requires the concentration of workers in production cells: factories and corporations.
The speeding up of the economic machine, required by economic growth, involves a growth in production and consumption. The accumulation of capital (equipment and finances) and capital knowledge (techniques and skills) has a catalytic effect on the acceleration of growth. The complexities of production require an increasing educational standard for those who would conceive, control, and serve the industrial machine.
I shall use Figure 16 to summarize the functioning of the economic machine. Its dynamics can be better understood if one follows the logic of the ecosystem: the great cycles and the main flows (energy and money), the role of various economic agents in assuring production and consumption, the malfunctioning of the economy and the attempts at regulation.
Classic models consider the economic machine to be a closed system even though it is a system open to the environment and not beyond or above the rules of energy. In order to have production, energy must follow its inevitable flow from a hot source to its breaking down in irretrievable heat in a cold sink.
The diagram illustrates this expenditure of energy as it travels through the economic system. The irreversible flow enters at top left, above "production," circulates in the form of goods, services, and labor, and emerges in the form of lost heat and unrecycled wastes (entropy).
One may wonder how goods and services can constitute a flow of energy. In fact material goods--"products"--are the result of transformations involving energy, information, and raw materials. They can be considered informed matter, matter that has received a particular form or that has been "informed" as the result of man's activity.
Matter is condensed energy; information is a form of potential energy. Goods (including foodstuffs) and services are therefore equal to a flow of energy. To each item of goods there is attached an "energy cost," say in kilocalories (see page 114 []). The feedback of energy in the form of work can be expressed easily in kilocalories expended per hour of work or in some other appropriate unit.
The sequence of white arrows, then, represents the energy that runs the economic machine. Clearly there are an expenditure of energy, as irreversible flow, and a global production of work.
Yet there is another flow related to the first: the flow of money. It runs in the opposite direction to the flow of energy. In effect, monetary units are exchanged for hours of work, information, or calories. The flow of money and the flow of energy balance each other and regulate themselves through "detectors" (cashier's desks, bank counters, transactions of all kinds) capable of measuring and balancing the speed of the flows that move in one direction or the other. Exchanges are made possible by a generally accepted system of prices and values that provides a basis for comparison and transaction. As the economists say in an almost poetic manner, the value of a good or a service is established at "the convergence of scarcity and demand." Price is the expression of this value of exchange; it is a "value meter" of distinctly practical use, since it constitutes an item of information that, while artificial, is essential in the functioning and regulation of the economic machine.
The monetary flow allows exchange by separating barter into two stages: one can sell what he possesses (his time, for example) for money, and one can buy with this money the goods and services he desires. Thus money is the lubricant--or the ballbearings--of the economic machine. Each bearing turns at the point of contact in a direction opposite to that of the flow of energy or work.
The speed of the circulation of money and the intensity of its flow depend on forces brought into play by the principal actors of the economic life, the economic agents. The two principal economic agents, the producers and the consumers (also called "industry" and "households"), are shown in the diagram. The other agents are financial organizations (banks), the state, and foreign markets. The diverse economic agents act as centers of decision that make choices and exercise powers which are then translated into forces capable of controlling, channeling, and orienting the flows of energy and money that circulate in the economic system.
Man is both producer (in industry) and consumer (in the marketplace). (In the ecosystem, remember, the two functions are accomplished by very different organisms--green plants and animals.) Yet man is much more than a simple producer or consumer.
In his role as "household," what activities in the economy can we attribute to him? His work in industry makes him a producer of goods and services. In exchange for this work he receives a salary, an income that permits him to assume the function of consumer (in the perspective of classic economic theory, to accumulate goods and services to satisfy his needs). He also has the power to save money, thereby creating capital. Above all, man is a creator. He creates information, technology, art, new ways of living and thinking. He can even store knowledge or ideas, thereby creating "knowledge capital."
The function of producing goods and services is assured by industries. The relationship between the functions of production and consumption appears in Figure 16. The input is a flow of energy, raw materials (or semifinished products), work, capital, skills, and income. The output is a flow of goods and services, salaries, innovations, reserves transferred to banks to be stored, waste material, and irretrievable heat. Following the arrows that indicate what enters and leaves "consumption," we see that input is a flow of goods and services, salaries, income to be saved, and education, and output is work, expenses, savings, new information (creations and inventions), and waste materials.
Producers and consumers can store two kinds of reserves: money (gained from past or present work), which creates capital, and information and skills, which create "knowledge capital."
Regulation of the flow of energy and money is carried out in part at the level of the labor market, in part at the level of the market for goods and services.
The three additional categories of economic agents (not shown in the diagram) have roles that are important as much for the regulation they perform as for disruptions they can introduce into the economic system.
Financial organizations--principally the banks--play a buffer role as money "reservoirs." Through the extension of credit to industries and to private individuals (credit being only another form of exchange), through investments, bank savings, and the issuing of bank notes, the banks regulate economic activity by controlling the rate of flow of money and the value of accumulated stocks. This constant adjustment of the monetary mass theoretically assures a balance between supply and demand in the market for goods and services.
The state plays an essential role in the regulation of the economic machine through budgeting and planning and by making direct purchases. Taxes and levies, subsidies, priority assignments of resources to one economic sector or another, control of the rules of competition, the fixing and freezing of prices, restrictions on credit, measures favoring exports, and the devaluation of money are examples of ways in which the state influences the economy.
Foreign markets are the rest of the world--everything located beyond the borders of the state. The state exports and imports goods and services; the difference between total exports and total imports constitutes the state's balance of payments, which has an important role in the regulation of the economic machine. Foreign markets also react to disturbances, in ways often difficult to anticipate, that influence the entire economy of a country. Political crises, devaluation or reevaluation, increases in the prices of energy and raw materials also affect the economy.
Let us illustrate the functioning and the regulation of the economic machine by considering the acceleration and slowing down of the flow of money and energy--which are well-known symptoms of inflation and recession. There are three simple but widely used indicators that measure the effects of control as exercised by the state or financial organizations on the economic machine: prices, employment, and the balance of payments.
The relationship between the flows of energy and money can be compared roughly to the coupling of two wheels turning in opposite directions, one inside the other. The outer wheel is moved by the expenditure of energy as it breaks down in the economic machine; it turns the inner wheel by means of a series of bearings. The inner wheel can also be braked or accelerated, thereby slowing or accelerating the movement of the outer wheel. This crude model will serve to illustrate different aspects of recession and inflation (Fig. 17).
Recession is characterized by the slowing down of the flow of money in relation to the flow of energy. (In terms of the preceding example, the inner wheel is braked and helps to slow down the outer one.) When the monetary supply diminishes (analogous to reducing the number of bearings), exchange becomes more difficult; friction increases and the "viscosity" of the market is raised. Locally there will be surpluses and an excess in the flow of energy. In the labor market the demand from industry will not be great enough to satisfy the higher supply, and in the market for goods and services supply will also be higher than demand (Fig. 18).
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When there is less money in proportion to the goods offered on the market, the result is a lowering of prices, a fall in production, and an increase in unemployment.
In a period of recession consumers prefer to wait before spending money; this lowers demand and slows exchange to an even greater extent. One becomes locked in a vicious circle--a spiral of recession that is capable of bringing the economic machine to a stop and having serious consequences for individuals and nations.
Inflation is characterized by the acceleration of the flow of money in relation to the flow of energy--by a higher "fluidity" of exchange. (The movement of the inner wheel increases the speed of the outer one, a little as though one had added bearings.) The same effect is obtained when the flow of energy slows down, which happens when energy becomes scarce and expensive (Fig. 19).
The monetary supply grows, as does its rate of flow. Thus the value of money falls and buying power diminishes. Everyone wants to buy before prices go higher. Prices mount and production increases to satisfy demand, but with the increase in salaries the costs of production rise and prices go up again.
We are locked in another vicious circle--an inflationary spiral that leads not to a stop but to an uncontrollable running away of the machine that brings tensions and inequalities to the society. With the flow of money moving more quickly and affecting the flow of energy, bottlenecks are created in the labor market and in the market for goods and services. The demand of consumers is greater than the supply of producers; this causes a constant escalation of prices.
The effects of recession and inflation are obviously dangerous, although a slight inflation can be favorable to expansion and to full employment. In fact economic experience shows that there seems to exist an inverse relationship between inflation and unemployment. This poses a problem for those responsible for economic policy, for it is generally in a period of inflation that full employment is maintained.[2]
In the area of foreign exchange a rise in prices can slow exports and increase imports, which upsets the balance of payments. When capital leaves a country whose money has depreciated, the outward flow can lead to the devaluation of the currency. Figure 20 illustrates the role of the third indicator, the balance of payments rate.[3]
Those responsible for the economic policy of a country will try to keep the balance of payments rate at or above l00. This implies certain constraints: some inflation is maintained and, in spite of relatively elevated prices, exports must continue. On the world scale the fact that all countries would like to export more than they import leads to tensions and inequalities.
The actual situation is infinitely more complex than that we have described, and this is what makes the regulation of the economy so delicate. Ideally, in a system of free enterprise, some sort of automatic price regulation in the market would allow supply to adjust to demand. This ideal regulation is illustrated in Figure 21.
Growth in demand causes a rise in prices (goods become more scarce). Businessmen will invest and hire additional labor in order to increase production. If the supply of goods and services resulting from this increase in production exceeds the demand of consumers, prices will fall and manufacturers will cut back production.
Unfortunately, automatic regulation of the market by prices cannot really work. In a free system the consumer should be all-powerful, capable of exercising a permanent "right to vote" represented by his freedom to purchase or not purchase a given product, to boycott or to favor any segment of the economy. In fact, by reason of public and private investments which precede demand and guide production, by reason of the power of advertising, the monopolies created by multinational companies, and the weakness of consumer organizations, this "right to vote" does not constitute a true regulatory power. Nevertheless the whims of the consumers, panic, and a conscious desire for nonconsumption in a given sector can all create waves that can disturb the economic system.
Banks and the state act by regulating the speed of flow and the rate of saving of money. In a period of inflation or recession the state can intervene at the level of prices (price controls, price freezing), foreign exchange (tariff barriers, controls on currency, devaluation), investment (major projects, high technologies), taxes, and salaries.
It is particularly difficult for those responsible for economic policy to avoid cyclical fluctuations, stagnation, and oscillations. One solution, that was chosen by the developed countries since the end of World War II, is the policy of continual growth: a state of inflation deliberately maintained to guarantee full employment and returns on investment in order to keep factories operating and to increase the material well-being of the individual.
But there is a price on everything. Accelerating the economic machine means pumping more energy from a depleting reservoir and dumping more waste and heat into the environment. Here lies the fundamental difference between the ecological machine and the economic machine. The basis of ecology is an irreversible flow of solar energy in unlimited quantity and a permanent recycling of materials; the basis of the economy is an irreversible flow of fossil energy from a limited source and an irreversible flow of materials from a nonrenewable reservoir of resources (Fig. 22).
Today the laws of the economy and ecology come face to face in a type of organization that is new in the history of the ecosystem. It is the nerve center of an immense network of exchange and communication, one of the most complex organizational forms in the social fabric: the city. Already more than 50 percent of the world's population live and die there; in the year 2000 about 80 percent of mankind will work and live in cities of more than 100,000 inhabitants. The city is born, develops, diversifies, and dies. It transforms energy, shelters man, and facilitates communication.
For millions of men and women the city is the principal place of employment. The development of business and industry has conditioned the growth of the city and the city in turn has modified the structure of industry. In their reciprocal adjustments and the special conditions they have created for labor and commerce, city and industry have brought about new ways of life and new aspirations. At the same time they have imposed between man and nature a sort of external biological layer that sometimes oppresses and often isolates us.
The city was born out of the needs of man: the physiological and utilitarian needs for shelter, food, health, communication, trade; the psychological needs for esteem, respect, education, and power.
The structure of the city acts as a catalyst to accelerate the development of philosophical and religious ideas, science and technology, the arts and political concepts. Through the organization of expansion, confrontation, experience--and restraint--this prodigious center of innovation attracts, promotes, and engulfs both men and ideas like a whirlwind.
The city is a communications machine, a massive network whose principal activity is the acquisition, processing, and exchange of information. It promotes in particular the plurality and variety of communication and exchange: for employers who can use a wide range of talents and specialties; for employees and consumers whose abilities and whose demands for goods and services are highly diversified.
The combination of these factors in the heart of the city has contributed to the almost explosive development of great metropolises during the course of this century. In 1850 only four cities in the world had more than one million inhabitants; in 1900 there were twenty; fifty years later, 140.
Each breakthrough in one field has repercussions in another that encourage its own development: scientific discoveries, industrial productivity, new products, new means of communication, new methods of transportation. At the same time there arise new ways of living, demands, constraints, conflicts, social readjustments. Thus the organic complexity of cities is woven.
The first cities were born nearly five thousand years ago in villages located in fertile areas that fostered communication: the fertile crescent of Mesopotamia, the valleys of the Nile, the Indus, and the Yellow rivers. The fertility of the surrounding land permitted the use of solar energy in agriculture. The storing of food and energy made possible the maintenance of the complex structure of the first cities, while the production of surplus energy increased the rate of growth and development. Communication in the deltas and by means of large river systems developed exchange, barter, and trade, allowed the confrontation of cultures, and inspired technical and social innovation.
Before 1850 there was no urban society; the great majority of people lived in villages where they produced for themselves everything they needed. From raw materials and energy (mainly food, fuels, wood, textiles, leather) they produced goods and services useful to the community. Thus the village was able to assure its own maintenance and survival. The first large cities were the home of the leaders and representatives of the society, the statesmen, clergy, military, nobles, bourgeois, and great merchants who formed a minority of about 20 percent of the population. This elite survived until the end of the eighteenth century thanks to their resourcefulness and the contributions of energy in the form of the labor of the villagers and the collection of taxes and levies of all kinds.
During the nineteenth century and early in the twentieth the Industrial Revolution and the division of labor led to specialization. Long-distance communication systems (train and telegraph) combined and reinforced each other, attracting to the cities an ever-increasing flow of the population.
The autocatalytic effect characteristic of large metropolitan areas began to exert its force. The pulling power of the cities' freedom of choice, higher wage levels, and possibilities for amusement and success accelerated the drain of people, energy, and materials from the periphery of the cities.
The modern metropolis rose from the density of population, the horizontal and vertical advance of construction, the organization of means of communication (automobile, telephone, elevators), and the creation of rules and codes that allowed cities to control their main functions (regulations governing working hours and traffic control, for example). At the same time cyclical waves were created by the great daily migration of workers into and out of the center city. The city has become a gigantic pump that sucks in and pours out, certain sections alternately filling and emptying in accord with working hours and weekends.
The growth of the city and its diseases, the multiplicity of its functions, and its daily behavior all suggest that the city reacts like a living organism interacting closely with an environment that it influences indirectly and that transforms it in return. Like the coral reef, the beehive, and the termite colony, the city is at the same time the support and the consequence of the social organism which lives at its heart. It is particularly difficult, if not impossible, to separate within every organism structure and function; thus one must not fear the analogy between the city and a "living organism" as long as the term appears within quotation marks.
What are the principal elements that make up a city, and how do they interact? On the map of a city the structural features hide the functional processes. Among the streets, avenues, and blocks of houses one sees stations, monuments, hospitals, and administrative buildings, yet everything seems frozen. The functional aspects of the city--its dynamics--escape observation. To grasp their complexity one needs the equivalent of an atlas that brings out in sufficient detail the urban body tissue area by area, showing the flow of energy, material, and information that circulates among businesses, administrative centers, residential zones, the environment. By regrouping certain main functional categories of the urban tissue, it appears possible to glimpse the overall portrait of the city and even to compare some of its structures and functions with those of other organisms, whatever their level of complexity (Fig. 23).
The interaction between individuals and organizations through communications networks makes possible the major functions of the urban system: utilization of energy and elimination of waste; production, consumption, and administration; culture, leisure, and information; communication and transportation; shelter and protection. The various functions result from different structures.
Housing. The largest single area of cities is occupied by dwelling places, which assure the establishment and the protection of the family unit. Residential zones represent, on the average, about 40 percent of the area of all cities.
Business and commerce. The city is the place of work for the majority of city and suburban dwellers, and industry produces the goods and services needed by the community. The distribution of products is carried out by the commercial sector, from its small shops to its chain stores and supermarkets. Food accounts for 25 percent of the budget of consumers in industrial countries.
Communication and transportation. These networks differ according to whether they transport people, materials, or information. The first two instances involve a layout of avenues and streets, a network of urban transport (subways, buses, taxis), and intercity and international systems (railway stations, seaports, airports). The third instance involves telephone lines and cables, telephone and postal systems, radio and television stations, the press and publishing houses.
Reserves. The principal storage areas in cities are distinguished by the character of what they store - energy, materials, or information. Large storage tanks hold energy in the form of fuel oil, gasoline, and natural gas. For perishable foodstuffs there are markets, slaughterhouses, refrigerated warehouses, grain silos. All kinds of materials are kept in stores and warehouses, and drinking water is kept in cisterns and huge reservoirs. Information is stored in libraries, archives, and computer banks; money is kept in bank accounts and vaults.
Administration and finance. Another important area of large cities is occupied by those agencies that contribute to the regulation of the social and economic balance: ministries, local and national governments, banks and other financial centers.
Distribution of energy and elimination of waste. Energy enters and moves through the city by means of electricity systems, gas mains, and gasoline stations. It leaves in the form of heat and garbage collected in sewer systems or by trucks. Wastes are eliminated in part in purification plants and incinerators, or they are accumulated in garbage dumps or used as landfill.
Other types of centers are more directly related to the daily activities of the inhabitants: culture and artistic life (museums, monuments, theaters); health care (hospitals and clinics); education (schools and universities); leisure activity and amusement (cinemas, stadiums, playgrounds, parks, cabarets); protection and security (fire and police stations, military installations, prisons); religion (churches, cemeteries). These different components of the city are often grouped into distinct sections within the city: business, amusement, and university districts, industrial or commercial zones, government buildings, museums, and green areas that are the "lungs" of the city.
Every city has its history; every city also has its daily routine. It feeds on tons of foodstuffs, fuels, and water to support the activities of its citizens at home and at work. For a city of one million inhabitants, daily consumption amounts to about 2,000 tons of food, 4,000 tons of fuel, and 630,000 tons of water. ( see notes [])
The city continually absorbs materials that replace worn-out structures or are used in the construction of new ones. Like a living organism, the city is the seat of a perpetual turnover of all its elements. This dynamic renewal can be seen in the coexistence of junk yards, sometimes a city block in size, with building supply yards. Such turnover has an effect at all levels of the organization of the city.
All cities release into the environment their metabolic wastes. For a city of one million inhabitants, daily wastes amount to 500,000 tons of used water containing 120 tons of solid particles, 2,000 tons of garbage, and 950 tons of atmospheric pollutants. The effect of pollutants on the lives of the citizens is only too well known, yet one such effect is worth discussing because it is a direct result of the metabolism of cities: the modification of their microclimate.
The city is a source of heat as a consequence of man's activities (heating, air conditioning, factories, automobiles). It also creates a "heat trap" because vertical surfaces reflect and amplify solar radiation, because the irregular outline of the buildings increases turbulence and reduces the escape of heat, and because running water from precipitation is immediately collected and drained off and cannot contribute to the cooling of walls and soil through evaporation. The temperature of the city, then, is always several degrees higher than that of the surrounding countryside. To the effects of this blister of heat add the effects of dust and aerosols in suspension in the air. These create condensation nuclei, causing the habitual haze and clouds that so often obscure the skies over large cities. The result: 30 percent fewer sunny days in winter and 10 percent more precipitation each year than in the immediate environs of the city (Fig. 24).
Another manifestation of the daily life of the city is the movement of its workers. In most large centers of population this creates a succession of concentric circles of residences traversed by busy roads. Once a centripetal movement has drawn the hordes into the city, automatic regulation comes into play: noise, pollution, stress, the high cost of living, and a lack of security cause a centrifugal movement toward the green suburbs and the country. In some cities there are downtown areas where glass buildings and slums stand side by side, busy with people in daytime and deserted at night, when violence and fear reign; the population live in the suburbs, spending an hour or two each day commuting to and from work by car or train (Fig. 25).
The city appears to be a self-regulating system that controls and balances the flow of its people between its center and its periphery. In the course of history the city has passed through a phase of explosive growth, followed by a period of stabilization, then stagnation marked by the degeneration of some areas, the appearance of slums, the further exodus to the suburbs, and the erosion of the center city.
Following the Industrial Revolution business concentrated in the cities where it found ideal conditions for development: density of population abundant manpower, intensity of exchange (of goods and services, money, information), and trade and commerce. The business of a city determines its personality, its shape, and its appearance. In almost all great cities there exists one or more functions of production that characterise those cities and give them life and purpose. The excavation of ore and the production of energy, large textile factories, foods, chemicals, iron and steel, mechanical engineering, and electronics are examples of such industries.
Today the businesses located in the centres of the great cities are chiefly producers of services, firms oriented toward commerce and distribution, or the central offices of national and international corporations which combine administrative, commercial, and financial activities. Factories are leaving the central areas of the large cities to relocate in the suburbs or in the country, where they are closer to the sources of energy, manpower, and raw materials.
To a stranger to the business life all businesses seem the same. The visitor sees only offices with the usual instruments of communication: telephones, typewriters, copying machines--occasionally workshops and laboratories. Their internal structure discloses itself on organization charts, but the charts do not show the movements of men and information that are the true activity of the company.
Nevertheless each business has its own life. It is born, it grows, develops, reaches maturity, and dies. Each business is one cell of production in the social organism; together a country's industries constitute a megamachine of production. Like a pump of gigantic dimensions, it sets in motion the flows of energy and money that course through the veins of the economic system.[4]
Business brings together various economic factors, organizes them, and uses them to produce goods and services that can be marketed. A business can be represented by a single person (a lawyer or an artist, for example), or it can take the form of an agricultural enterprise or an organization of craftsmen. In this more general view, "business is any activity that ends in the selling of a product or a service in the markets for consumption or production of goods" (Albertini) ( see notes []).
Business is also a decision center capable of providing its own autonomous economic strategy--one whose principal objective must be to "maximize profit within the technical and financial constraints that enclose it" (Attali and Guillaume). Thus business exercises two principal functions, one at the individual level, the other at the level of the society. The first function is to produce goods and services that will satisfy the needs of men; the second involves creating wealth, or generating through growth a surplus monetary value that, reinvested in part in the economic system, contributes to raising the standard of living of the entire population.
What makes a business run? The first requirement is organization, the establishment of specialized departments within the company and networks of communication that link them together. The production department brings together the factories, workshops, and machines. The commercial department oversees the system of distribution. Administration and management are the organs of planning and control. Research and development are the source of new products.
The second requirement of a business are the factors of production, the elements that actually set the company in motion: labor, capital, energy, material, and information.
Labor is the energy provided by the workers, the employees, and the officers of the company, who manufacture products and gather and process information.
Capital is financial resources and equipment.
Energy and material are the fossil fuels, electricity, steam power, primary raw materials, and semifinished products that will be used as starting materials in manufacturing or assembly.
Information is technology, licenses, patents--the intangible assets that are the result of the experience of the members of the company and their accumulated knowledge.
The material goods produced by the company through the combination of these factors are intended either for other businesses (production goods) or for individuals (consumer goods). Nonmaterial goods produced by the company are services (transportation, advertising, consultation, insurance). The company purchases its factors of production in specialized markets. This is shown in Figure 26, which is based on the diagram ( on page 25 []) but which opens up the feedback loops to illustrate the application to business and to show inputs and outputs.
Business buys or rents in various markets the factors necessary for the production of goods and services. When it needs money to develop or maintain itself, it can "rent" (borrow) money from banks by taking short-term or long-term loans. It can also "buy" money by paying the sellers in money of a kind peculiar to business: stocks. The sellers take a share (representing a fraction of the property) of the company and become stockholders.
Business deducts from its revenue the sums necessary to remunerate its production factors. These sums represent salaries (payment in exchange for labor), interest and dividends (in exchange for loans or capital), and royalties (in exchange for technology and patents). Money is also deducted to pay taxes imposed by the government. Business creates wealth only if it produces more in value than it consumes.
The choice of a company's objectives, its methods for achieving those objectives, and the controls that will keep the company moving in the right direction are the responsibility of management, led by the chief executive. Good management--efficient direction of the company--involves the adjustment of the company's objectives according to the various limitations of the environment in which it exists.
What are the main objectives of a business? The first is improvement in production--growth in the quantity of goods and services produced. Then comes the choice of financial resources and investments that will affect the firm's potential for profit. The company must maintain its competitive position through marketing and research and development so that the demand for existing and new products will grow. The training of factory workers, office workers, and management is important. Finally, the company's social function, its role as an agent in the transformation of society, confers on it a public responsibility. And all operational objectives merge to become one central objective: to maximize profit for the company.
Various restrictions require some readjustment of these objectives. They are social (workers' demands, conflicts, balance of power), financial (threat of takeover, availability of resources), industrial (production capacity), commercial (competition), and administrative (internal efficiency). The manager strives constantly to adapt the available resources to accomplish these objectives, taking into account the various restraints and their importance at a given moment. Toward this end the manager exercises functions of planning, organization, control, communication, and training.
The manager can be considered a comparator ( see page 85 []) ( and page 86 []) capable of transforming information into action. The act of transformation is the decision-making process. The hierarchical organization of the company is geared to facilitate the conversion of the instructions of the manager and his team into actions that involve important human, financial, and material resources. The management of a company can be thought of as a system of information/decision/action.
The role of the manager inscribes a loop that moves from objectives to decisions, from decisions to actions, and from the results of the actions to new decisions (Fig. 27).
This role necessitates two modes of action that may appear to be contradictory. On the one hand, the manager must act as a stabilizer: to assure the survival of the company and the security of employment, he must maintain its equilibrium. On the other hand, he must assure the continuous growth of his company. The application of these two modes of action determines the dynamic behavior of the company. Like any living organism, the company can enter phases of growth, stagnation, regression, and fluctuation.
The main purpose of the long-range strategy of a company is to assure growth while maintaining balance and stability. The traditional social and financial restrictions on industry give way to new restrictions that arise from the rapid development of industrial societies and the acceleration of economic growth.
The management team must see far ahead, decide more quickly, prepare forecasts and detailed plans for development, and come up with strict methods of control. The team must also take into account changes in the environment, in technology, in the tastes and the needs of people. It must consider its competition and the general rate of expansion of the national and world economies. These demands have led companies to adopt a growth strategy founded as much on the creation of new methods (technological, industrial, and commercial) as on joint ventures with other firms or the acquisition of companies that offer perspectives of diversification.
This growth strategy leads to a financial strategy that involves selecting the kinds of resources that will maintain a rate of growth compatible with the size and objectives of the company--while allowing management or the majority shareholders to retain some freedom of action.
Reinvestment in the company of a share of the profits promotes growth and financial independence. The company that can guarantee this kind of financing releases and maintains its own explosive catalytic process. The profits earned by a well-managed company can be compared to an energy surplus; the reinjection of this surplus in the form of strategic investments (consolidation of the financial status, strengthening of work forces, development of the distribution or production networks) is a kind of self-financing. It assures at the same time the maintenance of the structure, the accumulation of capital, and continued growth. The objective of every entrepreneur who establishes a business is to achieve a continuing process of reinvestment (Fig. 28).
Even should it begin with only two persons, a well-managed company can reach a level of efficiency that will assure its maintenance and growth. Usually it takes several years for a new company to reach respectable proportions; to grow more rapidly almost always means investing more money. To "put in orbit" a new company within a very short time requires--in addition to ideas, men, and technology--a particular type of capital, "venture capital," which represents the "potential energy" needed to fuel the "reaction." The risk can be high: how much energy will have to be spent before the "reaction" stops consuming energy and begins to produce the small excess quantity that will trigger the chain reaction? On the evaluation of such a risk is founded the art of the creation of new business.
From the end of the eighteenth century and into the nineteenth, following progress in anatomy, physiology, and medicine, numerous naturalists and philosophers (Worms, Spencer, Bonnet, Saint-Simon) extended their concept of the organism to society as a whole (the political and social organism). Often using naive or daring analogies, some of which we now find amusing, they nevertheless contributed to broadening the horizon of our knowledge about the life of man in society.
The metaphor of the living organism actually has great evocative power. In the words of Judith Schlanger ( see notes []), it permits the "integration of knowledge and meaning." It embraces complexity and interdependence in an integrated, autonomous whole in which the intricacy and variety of relationships between the elements often appear to be more important than the elements themselves.
In this section and the next we shall encounter again, at the level of organism and cell, familiar principles and patterns of operation. As in our studies of ecology and the economy, we shall observe the organism and the cell through the macroscope in order to concentrate on the broad lines of their function and regulation and to emphasize fundamental ideas of a new method of approach to complexity.[5]
Consider a man at his place of work: he carries out a specialized function. His labor may be manual (moving or positioning objects-- exerting strength) or intellectual (screening, classifying, processing information--organizing and controlling). His action on his immediate environment is thus translated into energy or information that is transmitted to other men and machines.
What does this man need to perform his work and produce his efforts? Above all he must have energy and information. Energy comes from the foods he buys and consumes regularly. Information falls into two categories: his initial capital, the education or training that gives him expertise in his profession; then the instructions that guide his work and the signals that come from his environment and from within himself. In exchange for his labor, this man receives a salary that enables him to obtain food and the other goods and services he needs (Fig. 29).
In order to sustain life, perform work, and receive and generate information, a particular kind of organization is needed. This organization relies on transformation centers (organs) and networks of distribution of energy and communication. The fundamentals of this organization are shown in Figure 30.
The system of energy transformation involves several organs and functions in an almost closed circuit. It uses food and oxygen from outside to set in motion converters, a distribution network, and systems for filtration, recycling, and the elimination of waste.
Energy-rich foods (sugars and fats) and indispensable raw materials (proteins and amino acids) pass through the series of converters of the digestive system (stomach and intestines). In the course of various transformations the substances extracted from raw foods are either used immediately or stored for later use. Oxygen in the air is breathed in by the lungs, which reject by expiration the body's most important combustion gas, carbon dioxide. Oxygen, the energy derived from food, and other essential substances are distributed in a fluid (the blood) that circulates in a complex network. This circulation is kept up by the work of a pump (the heart) capable of pumping from 5,000 to 6,000 liters of blood per day. Because metabolic wastes and combustion gases are returned to the blood, a system of filtration, recycling, and waste elimination is needed to cleanse this vital fluid. The principal filters are the lungs, kidneys, and liver.
Blood is regenerated in the lungs through the elimination of carbon dioxide and the absorption of oxygen by the hemoglobin of the red cells The kidneys filter and recycle blood after cleansing it of wastes, 99 percent of the fluid that flows through the kidneys is returned to the bloodstream while the remainder becomes the urine that carries off the waste. The liver acts like a chemical filter, retaining and destroying any substances that would be toxic to the system.
The information-processing system is composed of transducers and memories; organs of processing, control, and regulation; and two interconnected communications networks, one electrochemical (the nerves) the other chemical (the hormones).
The transducers transform signals from the environment into recognizable bits of information. The transducers are photoelectric (detection of light and images), acoustical (detection of sounds), chemical (detection of odors), and mechanical (detection of touch); they constitute the sensory system.
Information is stored in the memory and treated in different areas of the spinal cord and the brain--the olfactory, visual, and auditory zones. The control and regulation of major functions of the body are assumed by the brain or directly by the endocrine glands. Regulation often requires the cooperation of several organs; an internal network of signals is therefore essential. This network, by nature electrochemical permits the transmission of an electrical impulse (representing information) through the medium of the nerves.
The network also has a chemical nature: the release by an endocrine gland of a molecular signal--a hormone--in the bloodstream. All organs through which the blood flows will receive this hormone, but because the instruction that the hormone contains is coded, only the organs concerned will be instructed to undertake the regulatory action. These networks of communication are the nervous system and the endocrine system.
The body, limited by the skin, resembles a watertight bag that is 60 percent filled with water. Because the organs and their networks of communication do not have a consistency sufficiently rigid to prevent the entire body from collapsing under its own weight, the skeleton acts as a framework. Many of the 206 bones that make up the skeleton act as levers and are essential to all motion and to every movement. The contraction of six hundred muscles of the muscular system provides the motor force that acts on the levers or on tissues to bring about motion and movement.
The skin is a barrier that prevents microbes and foreign matter from invading the body. In the case of a lesion, the skin repairs itself through the process of healing. The skin's sensitive surface is capable of detecting, through nerve endings, information from the environment. It also plays a part in controlling the body's temperature. The body possesses a defense system that protects it from attack by foreign substances. Its weapons are antibodies, which are capable of recognizing and destroying foreign protein, and the white cells, which absorb and neutralize bacteria dangerous to the body.
The organization of the body enables man to act on his environment and to respond to the information or aggression that he finds in it. Physiologists have shown that the reactions of man and animals to these aggressions lead to three basic behaviors: flight, conflict, and adaptation.
When the environment becomes disagreeable, hostile, or dangerous, the organism can respond by leaving; it simply continues to change its environment until it finds a milieu in which it is comfortable. It can also attack or defend itself. And by conscious action it can modify an environment that threatens it and thus restore favorable conditions.
The body appears to be able to adjust itself continuously to new circumstances. In fact this adjustment is never perfect. Man experiences difficulties in adapting fully to a given environment; the adjustment often provokes frustration, anxiety, and illness. However, these are sometimes positive factors that are the basis of conscious or unconscious moves that lead to change or transformation.
A man threatened by the environment (or informed of an approaching pleasure or danger) prepares for action. His body mobilizes reserves of energy and produces certain hormones such as adrenalin, which prepare him for conflict or flight. This mobilisation can be seen in familiar physiological reactions. In the presence of emotion, danger, or physical effort the heart beats faster and respiration quickens. The face turns red or pales and the body perspires. The individual may experience shortness of breath, cold sweats, shivering, trembling legs. These physiological manifestations reflect the efforts of the body to maintain its internal equilibrium. Action can be voluntary--to drink when one is thirsty, to eat when hungry, to put on clothing when cold, to open a window when one is too warm--or involuntary--shivering, sweating.
The internal equilibrium of the body, the ultimate gauge of its proper functioning, involves the maintenance of a constant rate of concentration in the blood of certain molecules and ions that are essential to life and the maintenance at specified levels of other physical parameters such as temperature. This is accomplished in spite of modifications of the environment.
This extraordinary property of the body has intrigued many physiologists. In 1865 Claude Bernard noticed, in his Introduction to Experimental Medicine. that the "constancy of the internal milieu was the essential condition to a free life." But it was necessary to find a concept that would make it possible to link together the mechanisms that effected the regulation of the body. The credit for this concept goes to the American physiologist Walter Cannon.
In 1932, impressed by "the wisdom of the body" capable of guaranteeing with such efficiency the control of the physiological equilibrium, Cannon coined the word homeostasis from two Greek words meaning to remain the same ( see notes []). Since then the concept of homeostasy has had a central position in the field of cybernetics.[6]
The "internal milieu" is properly identified with the principal fluid that circulates through the body and washes the organs and the cells: blood plasma. Plasma is an aqueous milieu in equilibrium with the extracellular fluid found between capillaries and cells. It is a vestige of the primitive ocean inhabited by the first living organisms. Plasma accounts for 55 percent of the blood (the other 45 percent consists of red cells, white cells, and platelets). Plasma is 92 percent water and 8 percent molecules essential to life (glucose, amino acids, fatty acids, hormones such as insulin, adrenalin, and aldosterone) and ions such as calcium or sodium.
What are the main properties of plasma that make regulation effective? Temperature, maintained in the neighborhood of 37deg. Centigrade in man and most mammals; the concentration of calcium and sodium ions, the concentration of hormones and glucose; the pressure and volume of the blood; the number of red cells; and the acidity and concentration of water in the plasma.
Regulation is achieved by means of a control mechanism containing a detector, a comparator. and a memory bank that records the limits that cannot be exceeded. Each molecule or ion present in the plasma comes from a "source," can be stored in a "reservoir," and disappears in a "sink." A general model of a typical physiological regulation is presented in Figure 31.
Consider, for example, the regulation of the concentration of calcium. Calcium plays an important role in muscular contraction and in the formation and composition of bones- Its concentration in the plasma is maintained in a remarkable way at a level of between 8.5 and 10.5 milligrams per hundred milliliters. Calcium enters the body daily in food (milk in particular contains a considerable amount of calcium). It can be stored in the large calcium reservoir of the bones. Very little calcium is excreted in the urine. The regulation of the concentration of calcium in the plasma is shown in Figure 32.
When the level of calcium falls below 8.5 milligrams, a molecular detector in the tissues of the parathyroid glands sends a signal that triggers the synthesis of the parathyroid hormone. This hormone, released into the bloodstream, acts in three ways: it extracts more calcium from the bones; it slows the loss of calcium in the urine; and it increases the amount of calcium absorbed from the intestines. Consequently the level of calcium in the plasma rises. If the level should rise above 10.5 milligrams, a detector in the thyroid gland sends a signal that triggers the synthesis of the calcitonin hormone, which acts to increase the storage of calcium in the bones, thereby reducing the level of calcium in the plasma.
The regulation of other "constants" of the plasma involves the brain and behavior. One of the first detectors to be informed of internal modifications of the body is a region of the brain that plays an important role as the center of integration of the common life functions (hunger thirst, regulation of body temperature, and sexual behavior). This center is the hypothalamus, director of instinctive functions.
Hunger. When we are hungry, the hypothalamus detects a lowering of the level of glucose, amino acids, or fatty acids in the plasma. It integrates other signals as well: body temperature, distension of the stomach. These increase the sensation of hunger. The constant of time in this regulatory mechanism is essential; a considerable period can elapse from the moment one first feels hunger to the moment of eating. A rapid response mechanism should increase the level of glucose in the blood. Thus the adrenal glands detect this disturbance of equilibrium and secrete adrenalin, which transforms glycogen reserves in the liver into readily usable glucose. In less than fifteen minutes the level of glucose begins to rise. Over a longer period (after about two hours) the secretion of hydrocortisone by the surrenal cortex permits the transformation of protein into glucose. The results of this action appear only after six to eight hours.
Thirst. When the plasma becomes too concentrated, the hypothalamus sends a signal to the hyphophyses gland, which secretes an antidiuretic hormone. This hormone releases the flow of vasopressin, which acts on the kidneys. The urine is now made in more concentrated form, a part of the water being recovered and used to dilute the plasma. At the same time, one feels a sensation of thirst--which encourages behavior that will lead to the absorption of liquids.
Temperature. Temperature is carefully controlled at 37deg. Centigrade in man and varies between 35deg. and 44deg. Centigrade in most warm-blooded animals. This control is managed at the level of the hypothalamus, which is sensitive to heat and cold. Regulation depends on thermal insulation (clothing, fur, body fat, heat, air conditioning) and on the internal production of heat (combustion of fats, contractions of the muscles in the presence of shivering). The loss of excessive heat is accomplished through the blood and by dissipation through the skin. The evaporation produced by perspiration cools the body considerably.
Numerous other kinds of regulation operate at the upper level of the cortex, bringing into play multiple facets of behavior. These regulations are no longer based on simple signals of internal malfunction but on a multitude of information from the environment: signs or symbols of different hierarchical value, integrated into rules of conduct and capable of triggering a great variety of behavior. Following his personal scale of values, a man can decide to go on a hunger strike and carry it on to the death. In this way he chooses a finality other than the maintenance of his own organism; he no longer responds to the "signals of internal malfunction," to which the gland or the organ is obliged to respond.
Pleasure and fear also enter into the picture. In one region of the hypothalamus there are bundles of nerve fibers that appear to play a vital role in the body's reward system. If we use electrical impulses to stimulate one of these bundles in a laboratory animal, the animal begins to eat with a relentless hunger. In the presence of an animal of the opposite sex it begins to copulate with frenzy. If we make it possible for the animal to excite and gratify itself, it will devote itself to this narcissistic activity until it is exhausted, provoking the stimuli as many as 8,000 times a day. On the other hand, any stimulation of the complementary bundles of nerve fibers induces characteristic reactions of anguish--jumping, biting, sharp cries, defensive postures.
The actual regulations of the organism require complicated circuits extending well beyond the borders of the organism and into the heart of its environment. Consider again the image of the man at work in business or industry. The quest for reward, for recognition, even for a certain gratification (in domination, in power, or simply in work well done) is combined with a constant apprehension of the discipline and the hierarchy of the company, and this has a continuous effect on the regulations of his internal equilibrium and the regulations of his equilibrium with his immediate environment. Stress, anguish, frustration, joy, pleasure, and the sense of well-being all exercise an everyday influence on hormonal regulation, on the mobilization of energy resources, and above all on our physical and mental health.
Thus the body is continuously informed of the state of its organs and its internal equilibrium, thanks to the signals that come from without and within. The brain manifests itself as the integrator of these signals, not as a supreme hierarchical center where decisions are made. There is no "leader" in the human body.
At the level of the living cell the concepts of the organism and society converge and illuminate each other. The metaphor of the living organism has had considerable success in its application to society; now it is the turn of the concept of society to help explain biology. "The cell, society of molecules," François Jacob writes.
At the conclusion of our opening of the Russian dolls, the last little one--that of which our knowledge is most recent--will clarify in retrospect the entire hierarchy of the levels of complexity that have led to it. The loop is going to close. From the solar energy transformed by the ecosystem to regulatory reactions that maintain the life of the cell, including the action of man on his environment, everything holds together, is connected, circles around, and overlaps.
The cell of a higher organism maintains its structure, regulates and controls its metabolic functions, grows, reproduces, performs work, exercises a specialized function within an organ, and dies. These are the functions that characterize life: self-preservation, self-regulation, self-reproduction, and the capacity to develop (Fig. 33).
Life confronts inert matter with its energizing activity. Unlike crystals, which exist and survive only in static equilibrium with the environment, the cell recurs continuously, in its most intimate composition, thanks to the flow of energy and the materials that pass through it. In spite of the molecular upheaval the cell maintains its internal organization in the face of a natural tendency to disorder. The key to this stability rests in its genetic information bank.
Structures and functions are therefore inseparable. The maintenance of structures can be guaranteed only by the energizing activity of the functions. Structures rely on construction materials arranged according to rigorous spatial organization. The functions are exercised through the medium of a temporal organization which rests on myriads of elementary reactions that are tightly coordinated and synchronized. The cell must have transforming agents to maintain its structure and functions. In the cellular society these agents are molecules that form limited chemical categories.
The two main categories of chemical agents in the cell are giant molecules (macromolecules), the proteins, construction elements or catalysts that control cellular activity (the enzymes), and the nucleic acids (DNA and RNA), which store the necessary information for the assembly of proteins and enzymes and for cell reproduction.[7]
The other basic instruments of cellular life are signal molecules that make communication possible, energy-rich molecules, small molecules that act as building blocks, electrons and their carriers (essential in the transfer of energy), and water molecules. This entire population can be measured. In a simple cell such as a bacterium--a thousandth of a millimeter long
-- there are from 10 to 100 billion molecules of water, 70 percent of the total composition (or population) of the cell; from 100 million to one billion molecules of average size, representing almost 500 different chemical types (sugars, fats, amino acids, pigments); and five to ten thousand distinct kinds of giant molecules of protein and enzyme that make up a population of about five million molecules. Finally, one kind of macromolecule alone contains the necessary information to direct the manufacture of all the others: deoxyribonucleic acid, or DNA.
The effectiveness of the interactions and exchanges among the various molecular instruments is assured by a small number of supramolecular organizations. Through the medium of these organizations the major functions of the cellular society are performed. The conversion of energy occurs in the mitochondria, the molecular power plants; the storage of energy and its reserves in the vacuoles; the manufacture of protein in the ribosomes, the assembly plants; the storage of information in the nucleus of the cell; and the filtration of signals to and from the outside, the protection of the cell, and the catalysis of a large number of essential reactions are performed at the level of the membrane.
Thus the cell appears to be a self-regulatory system, a transformer of energy, capable at all times of balancing its production in terms of its internal consumption and the energy it has at its command.
In order to relate the activity of the cell to that of the body as a whole, we must consider two complementary functions, respiration and nutrition and what happens at the cellular level.
Respiration is the basic reaction of animal life. It is a combustion in the presence of oxygen that occurs in the mitochondria. This reaction enables the cell to process food from outside sources in order to obtain the energy it needs to synthesize materials, to move about, to secrete special substances, to send electrical signals, and to reproduce. Seen from this angle, respiration appears to be a much more widespread activity than simple pulmonary ventilation, with which it is often confused.
In terms analogous to the industrial process of transformation, respiration needs fuel, combustion primer, and catalysts. The principal fuel of the cell is glucose; it is extracted from food by a series of converters in the digestive system and home-delivered to the cell by the distribution network of the capillaries. The combustion primer, obviously, is oxygen from the air, carried by the hemoglobin of the red cells and similarly home-delivered into the liquid that bathes the cells. The catalysts are the enzymes that speed up and control combustion and the use of the energy released. This raw energy appears first in the form of electrons.
The ultimate purpose of respiration is to recharge the "batteries" of the cell. Everything that lives uses a particular type of energy-storing molecule whose role is analogous to that of a portable battery that provides energy wherever the cell needs it to produce chemical, mechanical or electrical activity. The molecule is ATP (adenosine triphosphate). When it has released its energy (when the battery has discharged), it is ADP (adenosine diphosphate). The cycle of combustion and extraction of electrons can be compared to a generator and the recharging chains of ADP and ATP to a charger. Figure 34 illustrates and summarizes the role of each agent.
This universal model will serve to explain three important aspects of the molecular functioning of the cell: the transformation and utilization of energy, the complete regulation of cellular metabolism by the enzymes, and the work of a specialized protein, hemoglobin.
The small molecules that result from digestion make up the primary raw materials of the cell. These are principally glucose, amino acids,
and fatty acids. But before being used in the combustion reaction they must undergo preparation, for the generator operates only with a highgrade combustible: the molecule of activated acetic acid.
The successive reactions that insure this preparation and the extraction of electrons follow each other in strict order. At the conclusion of the series, the reactions have formed a closed cycle: the principal residue of the combustion is combined with a new molecule of activated acetic acid and reintroduced at the start of the new cycle. This cycle, which sustains the life of every complex cell, is called the Krebs cycle;[8] it is the "generator" of electrons.The flow of electrons from this generator recharges the "batteries" of the cell by means of another series of reactions linked to the first.[9] This combined process simulates the "charger." Along the entire chain of the charger the electrons gradually lose their energy. Finally they come to the oxygen that awaits them at the end of the series (and represents the lowest level of energy in the cascade of electrons). It is this expenditure of potential energy that powers all the machinery of life.
What happens when violent physical effort is required of the body, as in muscular exercise or flight in the face of danger? The determining factor is the number of "run-down batteries," or the relationship between ADP and ATP (discharged and charged molecules). This relationship conditions all activity in the "generator" and in the "charger."
The mitochondrion can be compared to a service station where the batteries of a number of customers are regularly charged and the station attendant always has charged batteries on hand. Ordinarily the ratio of discharged to charged batteries is very low (about l: l00); the same is true in the cell when the ratio of ADP to ATP is very low. Then the charger is little used. The chain of electron carriers, like the generator, runs in slow motion. The demand for combustibles and oxygen is low, and the body stores glucose as glycogen and fatty acids as fats. Man sleeps, rests, and recuperates.
Then, when effort is needed, the muscles work, consuming ATP, and the "batteries" run down. The quantity of ADP (run-down batteries) increases rapidly the ratio of ADP to ATP becomes very great (perhaps 100:1). The "service station" is flooded with calls to recharge batteries, and the recharging activity speeds up. This activity uses up more electrons and oxygen. The generator cycle turns faster and faster, consuming the stored combustibles and giving off more carbon dioxide. The quantities of glucose, amino acids, and fatty acids drop in the extracellular fluid and then in the plasma, and wastes accumulate. A full series of detectors in the glands and in the brain register the changes in equilibrium. Pulmonary ventilation accelerates, providing more oxygen and eliminating carbon dioxide. Heart rhythm becomes markedly faster. The blood circulates more rapidly and drains off the wastes, while the contraction of some blood vessels and the dilation of others allows an improved distribution of the blood, especially where effort is concentrated. The skin becomes red, the person becomes hot and sweats. The work of the mitochondria has had an effect throughout the entire body (Fig. 35).
After the effort is over, the drop in the level of glucose, fatty acids, and amino acids in the plasma is detected by the hypothalamus. The body becomes hungry and seeks food to recapture its strength. When activity continues for a long time--in the case of prolonged fasting, for example--glucose and reserves in the liver are not enough. The body steals from the reserves of amino acids in the proteins that build the cells. It is like burning the walls and the furniture of one's home. But one cannot risk losing more than 40 percent of one's body weight without risking death. After a certain stage the balance cannot be reestablished the damages are irreversible.
To slow or speed up a metabolic process catalyzed by a chain of enzymes (analogous to a sequence of machine tools on an assembly line), the cell exerts a simple yet harsh trick. In the short term the assembly line can be slowed or stopped at the start of each series; in the long term all or part of the assembly line can be suppressed. A speed-up in production is achieved by increasing the number of machines in each assembly line or by installing parallel lines. Thus production can be adjusted in a very short time, enabling the cell to meet a considerable demand.
The ultimate control of cellular activity must pass eventually through the production (or the blockage of production) of the enzymes. This production takes place in the assembly shops of the cell, but the original plans for all the special features of enzymes that the cell needs never leave the nucleus of the cell.. Thus if the plans cannot be copied inside the nucleus, no enzyme will be assembled in the workshops. As long as the "copying machine" functions, production continues without hindrance.
Among the genes in the nucleus of the cell there is a battery of switches, the repressor molecules, that can control the operation of the machine that copies the plans. Each repressor recognizes a specific signal that orders it to stop or to carry on the copying of the plans of enzymes specialized in a given task. This regulating signal is generally a small molecule that attaches itself to the appropriate repressor and activates or deactivates it (Fig. 36).
Here we see in action the important signal molecules on which relies a large part of the information that circulates in the cells and throughout the body. These molecules are recognized by specialized detectors located, as we have seen, in the glands and organs. They turn on or off chemical switches (like the repressors) and they trigger or block the synthesis of enzymes and (indirectly) hormones and other molecules essential to life.
The functioning of the repressors and the functioning of the enzymes are possible only because of recognition mechanisms that act between nucleic acids, proteins, and the regulatory molecules. The recognition of information according to the shape of the molecules (their morphology) is very general; it is the basis of the universal language of internal communication used by all cells.
Hemoglobin is an extraordinary machine, a veritable "molecular lung." ( see notes []). Its purpose is to carry oxygen from the lungs to the tissues, via the arteries and the capillary network. It uses the network of veins to return directly or indirectly to the lungs the carbon dioxide remaining in the tissues. On one side the blood is bright red; on the other, dark brown.
The hemoglobin must give up its oxygen at the right place in the tissue and not return it to the lungs. And this is one of the paradoxical qualities of this molecule: it is capable of taking on oxygen as easily as it is of discharging it.
As in the case of most proteins, the properties of hemoglobin depend on its molecular structure and its "anatomy." It is made up of four blocks, each linked with the other in a compact structure by a sort of molecular staple. Each block is a protein, globin, composed of a chain of amino acids all linked to one another. Near the center of each block lies a molecule, flat as a disk, which contains an atom of iron in its center. This molecule is a pigment, the heme, that gives blood its red color (Fig. 37).
This pigment and its atom of iron constitute an "active site" that is able to recognize and to capture oxygen molecules. There are four such sites, so the hemoglobin can bind four molecules of oxygen. As the absorption of oxygen in the pulmonary tissue proceeds, molecular staples pop out. Thus the four blocks modify their arrangement in space, which makes the absorption of other oxygen molecules much easier.
The entire working of hemoglobin rests on a simple property of iron: in the presence of oxygen its diameter decreases by about 13 percent. This diminution in size allows it to lodge more readily in the plane of the flat pigment molecule. The light movement that follows it is amplified by the chain to which the iron is attached, which serves as a series of levers and springs. Tension can make one of the clips pop--a little like a snap fastener that pops from its place; consequently a block changes slightly in shape and position in relation to others. This makes it easier for the next block to bind another molecule of oxygen, and the process continues through the succeeding blocks.
Hemoglobin discharges all its oxygen in the cellular tissues, the more readily as the molecules of oxygen are freed. Because of this mechanism, hemoglobin pumps oxygen in only one direction, from the lungs to the tissues. In fact, in every organism there is a balance between two kinds of hemoglobin, the deoxidized form and the oxidized form (Fig. 38).
Everything that stabilizes the deoxidized form allows more oxygen to be discharged by displacing the equilibrium in that direction. This is the role played by regulatory signals that are present in cell tissues-- like the molecule of carbon dioxide or the acid ions (Ht), the principal wastes from the activity of the cell ( see page 51 []). Now we can understand why every effort makes us breathe more rapidly.
The activity of the hemoglobin is based on modifications in shape triggered by regulatory signals. These are allosteric changes (a term created by Jacques Monod and J.-P. Changeux, meaning "different form"). The behavior of the great majority of enzymes rests on this fundamental mechanism.
In the preceding pages we have illustrated the reactions of transformation of energy and of regulation that characterize life. You may have noticed that in the diagram on page 50 some arrows arrive from nowhere and lead nowhere (glucose and carbon dioxide at left oxygen and water at right). In fact what is lacking in this chain of life is an essential link, the green vegetable cell. This cell manufactures energy-rich glucose during periods of photosynthesis with solar energy, water, and the carbon dioxide released by animals. This is what introduces into the atmosphere the oxygen necessary for respiration. Thus the loop closes on the ecosystem and solar energy.
From the main cycles of life to the tiniest molecular cogs and the subtle play of electrons, this last plunge into the heart of the cell has clarified, I hope, the unity of the fundamental mechanisms of nature and society. The enzyme, the cell, and the organ represent--each at its own level--the catalysts of the many functions that maintain, regulate, or transform the organization on which their lives depend. Man, too, is one of these catalysts. To understand better how they act within their own organisms can lead man to better behavior, from within, in the transformation of the complex systems on which he depends: business, the city, society.
In order to be effective his action will have to depend on a new method of approaching complexity, a method capable of embracing at the same time organisms, organizations, and their interdependencies--and capable too, of integrating, beyond the analytic approach, "knowledge and meaning."