The longest of these is what Colinvaux calls the "Mediterranean episode." He gives this as approximately the flourishing of Greek civilization and the conquest of Alexander the Great, through the rise of Rome and the Punic wars, through the collapse of the Roman Empire and the partitioning of its former lands between the Christian barbarian kingdoms, the Islamic caliphates, and a remnant of the Eastern Roman empire.
I've already alluded to many of Colinvaux's insights in previous entries, but a few points are worth mentioning (all emphasis mine). The beginnings of the Mediterranean episode come from settling down into urbanized village life:
The immediate effect of switching, even gradually, from barbarism to a settled city life is that the population grows. The new economy produces more food, the new niche permits people to be content when living more closely packed, each couple can raise more children and does so, and the numbers of people steadily increase. So it was in Greece.On the effects of Greek geography and culture on their war-making ability:
The ecological hypothesis predicts that this process will lead to colonial enterprise, to trade, to much fighting, to an oppressed proletariat, to high technology in war, and to the creation of empire by military means as a popular goal. The written history of Greece shows how each of these things came about, and even reveals that the Greeks knew something of what was happening to them. (p.114)
The pattern of these various consequences of rising numbers and changing niche in Greece was influenced strongly by Greek geography. The land is both mountainous and dissected by embayments of the sea. This meant that scattered city states could grow in a partial isolation from each other, having defensible state boundaries and well limited patches of local resource. It may well have been this isolation of each Greek city-state that helped to foster the refinement of their remarkable military hardware, protracting wars between neighbors, letting victories be indecisive so that return engagements could follow after a few years spent in perfecting armament. Certainly it is true that the first and most fundamental of civilized fighting forms, the armored phalanx, was better refined in Greece than in any nation of which we have record.(pp. 114-115)
Highly civilized weaponry was a fact of life to free Greek citizens. Every independent man owned the weapons of hoplite infantry and knew how to use them. His own money equipped him for war. He could be "called to the colors" at any time, and he went willingly. Front line soldiering was both the duty and the privilege of the substantial citizen, and the poorer classes went to war merely in his support. The better-off fought; the less-well-off supported. And this was reasonable, because the colonies and trade on which the high standards of life of the wealthy in a Greek city depended could be guaranteed only with expensive weapons. (p. 118)The Greeks responded by colonizing the Mediterranean; "like frogs around a pond" according to Plato's description:
Each of the major city-states of Greece sent out colonists to found tributary cities elsewhere; scattered round the coasts of the Persian dominions, in North Africa, in Sicily and beyond. This was how local city states, each pressed into an ancestral valley of the rugged Greek terrain, had found opportunity for businessmen and adventurers alike. ...The people of Athens could find more niche-space for the Athenian way of life by building colonies which would duplicate Athenian ways, and they did so.
The state of Athens grew through colonies and trade in a somewhat different way. The land was not lastingly fertile, like the island of the Chalcidians, having soils which were easily denuded by agriculture. Ecologists know well the Mediterranean soils, like those of Attica where Athens was built, and the story they have to tell. They are now red, being given the name of "terra rosa." This is the red of minerals weathered under a mild climate. But once, in their forested antiquity, the soils were probably brown, because they were well mixed with the humus and leaf litter of the forest above. Good agricultural soils need such an admixture of humus. But the people of Attica cleared the forests, burned off the brush, plowed the land, took away the crops to eat in their villages, and let the burning sun of the Mediterranean dry the soils so that wind and water could sweep the humus away. The fertile brown color went, and the unproductive red mineral mass of the terra rosa remained. This was the result of the first intensive agriculture in Attica, and the Greeks themselves understood the cause. A sentence in Plato reads, "all the rich, soft soil has molted away, leaving a country of skin and bones."In addition to colonization and trade, there was also military conquest, both as a way of increasing niche space and of controlling population growth. The most celebrated practitioner of this was Sparta:
But the poorness of the soils of Attica seemed to have helped the trading side of colonial life to grow with particular energy. Athenian men of business concentrated on taking from their own land only what it would yield easily, which happened to be olive oil and silver, and they proceeded to build ships so that they could trade these commodities for the other things they needed. There was no living for farmers any more, except for the few who tended the olive trees, because the people's grain was now grown by barbarians in the Ukraine, and the people had to crowd near the granaries in Athens and become the servants of manufacture. There were now rich and poor in Attica as there had never been before. (pp. 119-121)
In addition to colonies and trade as answers to the needs of growing numbers, there is the expedient of direct conquest and elimination of neighbors. In a nation which had invented such a clinically effective instrument of compulsion as the phalanx, this expedient was sure to be tried, and it was. The most celebrated exponent of this art of neighborly aggression was Sparta. But aggression on neighbors meant fighting other Greeks who also knew the effectiveness of lines of armored spearmen. Spartans could not have the technical superiority over fellow Greeks which made it so easy to force other nations to yield for Greek colonies, and had to develop a society organized around the needs for absolute military efficiency in order to prevail. (p. 121)About those Spartans:
Spartan discipline is legendary. But it is important to note that it was the well born youths who were trained to this asceticism in war. In battle, the hoplite shield wall held by young men of good Spartan families was supported in the rear by up to eight ranks of helots, or slaves, who passed forward spare weapons. It was this perfection of armored warfare from Sparta against which Herodotus tells us the Persian waves of infantry broke at Plataea, and it was this philosophy of war which drove Leonidas to make his last stand with the three hundred All this Spartan excellence in war was clearly and directly the achievement of the ruling class and in its own interest.
Both the Spartan military society and the commercial society of Athens worked by compressing the niches of the mass; specialized labor was needed, often dull, repetitive, mechanical, soulless labor. It must be performed by people whose ancestors, only a few generations back, were free farmers; and in a world where free, farming, barbarian societies still existed on all sides. Freedom beckoned in memory and by example. So the proper functioning of the state required compulsion. The poverty of people with compressed lives, which is always the result of letting populations rise to soak up the resources released by new technology or conquest, took on the special institutionalized form of slavery. A slave was merely a poor man made to keep quiet about his inevitable lot by physical coercion. (pp. 121-122)All of this meant that the Greeks were both pressed by the weight of numbers, and had developed the superior techniques in warfare that allowed them to dominate their neighbors:
The Greek city states had already, by the time of the Persian wars, found themselves in another of the dilemmas of growing numbers and ambition—depopulation of the countryside at the same time that the towns became crowded. This is a normal consequence of growth...As people better themselves by the trade and industry of the city, so it often happens that the city comes to support itself on the products of that trade. It may well be that the city even comes to meet its basic needs, as for food, from regions other than its own original hinterland.
This will be particularly so if the city begins to trade with fertile agricultural states whose lower standards of living let them sell food to the city cheaply. The result is neglect of the ancestral countryside and an even more rapid drift of the country people into the cities...The Greek historian Thucydides saw the working of this process when he noted that Athens and Corinth were "crowded" and had to feed their people with grain imported from the Ukraine. Notice that he was not using the word "crowded" to connote wretchedness, for he thought of all the well-to-do people of these very great cities as part of the crowd. The people were living on Ukrainian land which fed them, and on all the coasts with which they traded, so they had ample resources, though "crowded."
Interestingly, Thucydides did not think Sparta to be "crowded" in this way, though he notes that the Spartans did import their food from Sicily. Sparta's land empire apparently left its people less densely concentrated, though she too was living on the produce of other people's real estate.
So the individual city-states of Greece each grew out of barbarism through settlement, manufacture, trade, colonies and dense concentrations of urban people to an eventual dependence on imported food for the large numbers of their proletariat even as predicted by the ecological hypothesis. The wealthier ranks of their societies took to war as they tried to expand and defend their broad niches, and they invented advanced techniques of fighting, particularly stressing body armor. They formed confederations of cities to meet attacks from the powerful, especially when their expansions into Asia provoked attacks by imperial Persian armies. The hypothesis predicts next that increasing demands made upon each city government would result in such wars that the different parts of the growing nation will come under strong central rule and loose its armies toward imperial conquests of its own. All this was about to happen.(pp. 122-124)These were the conquests of Alexander the Great, which we have already covered. The Greek peoples took that huge population and military superiority, and used it to defeat the Persian Empire, establishing a world empire in the process (other Greeks such as Croesus of Lydia, who invented coinage, had made earlier failed attempts).
Indeed, before the Mediterranean episode, we could speak of the "Near Eastern Episode" which arose from the beginnings of agriculture in the Fertile Crescent, and included the first empires such as the Sumerians and Akkadians, the Assyrians, the Babylonians, the Egyptians, the Hittites, the Hyksos, the Phoenicians, and finally the Medes and the Persians whom Alexander conquered. It would have been nice to analyze these empires from the point of view of the ecological hypothesis. Interestingly, Toynbee notes that Egypt managed to survive culturally for so long by the "fossilization" of their culture. Also worth noting is the flooding of the Nile as a protection against erosion, something that was not possible in the Near East (where floods did not coincide with planting), Greece, or North Africa (which needed to be heavily irrigated).
Meanwhile, the agricultural villages of the Italian peninsula were moving in their own direction:
Civilization was progressing in Italy, no less than in Greece, but it was influenced by the long secluded shape of Italy. There was no scarcity of good agricultural land in this long peninsula, so the Italians had less need to turn to the sea for trade or conquest. Populations could grow for a long time with no more than the local adjustment of borders between tribal states. Then the states which deemed themselves the most worthy resorted to the usual armed aggression against their immediate neighbors. Techniques of land warfare were developed early and earnestly; the primitive infantry phalanx of armored spearmen probably appeared in Italy as early as it had appeared in Greece, and when Italian fought Italian it was to jab this deadly instrument against another equally deadly. And yet the military evolution of Italy went neither in the direction of the Spartan absolute expertise in conventional war to the ultimate development of the phalanx into the terrible instrument of Macedon, but into something quite different, the legion. (p. 131)The legion proved to be the decisive military weapon in establishing the Roman empire. The major rival to Rome in the Mediterranean theater was thassalocracy of Carthage, founded by the Phoenicians. Like any trading regime, they had developed expertise in war. Yet hemmed in on the coast of North Africa, with vast deserts to the interior, they developed along different lines than Rome. Colinvaux's insights on the development of Carthaginian civilization and the wars are particularly interesting:
Carthage was in a fertile place, but there was not much of it. The people could not win more resources by aggression on neighbors, for the neighbors held only desert. Instead, the Carthaginians took the approach of the green revolution, terracing and irrigating the land they had, making their narrow strip between the desert and the sea so green with crops that it was eventually to be the marvel of Roman visitors.
But when their growing civilization needed more opportunity, a broader niche for the more enterprising, there was no way of meeting the need in their narrow patch of land. Logic says that trade and then colonies were the only practicable ways to provide for Carthage an expanded way of life. We know that these solutions were, in fact, used to the extent that they became a national way of life. The Carthaginians lived by trade westward, where there seem to have been few trade rivals, leaving their mark round Africa almost as far as the equator, and round Spain to reach northern Europe. And they planted colonies in barbarian lands as the Greek cities did.
But they did not develop an advanced technology of war. Carthaginians had few civilized states with which to fight, none alongside their home city, few near the barbarian lands which they expropriated for colonies. Good weapons, good armor, good courage, and the shield-wall approach of the primitive phalanx were all that were needed to secure the colonial lands of their earlier expansion. Carthaginians were not tried by earlier expansion. Carthaginians were not tried by civil war early enough to force them to give pride of place to military technology as the Greeks and Romans had had to do. Carthage had fine fleets, as befitted a trading state, but an indifferent army. When the real ecological wars came, this was to be her undoing.
So we have a nation of ambitious merchants and ebullient seamen, of wealth from trade to patronize arts and material things, of high consumption, of safe, confident, well-fed families. The numbers of people in this nation must surely grow, nor will the new sons be content with less than what their parents had. The Carthaginians were going to feel the need for yet more land overseas. We have no state statistics, no census, to tell us that the Carthaginian numbers did grow, but there is evidence enough that they must have grown in what the Carthaginians did: trade, colonies, and, at the last, outright attempts at foreign conquest. It was then that their vital interests first clashed with those of Rome.
Roman authors, and our school books, tell the tale of these wars as a struggle to see which state should be mistress of the world; Rome, with all Italy already in its power, or the trading city of Carthage, sweeping the Mediterranean Sea with merchants and fleets. Rome did indeed go on to conquer and enslave every nation within reach of its terrible legions. But the war was not over who should be "mistress." It was a struggle for raw survival by the civilized folk of a trading state against the resources and weapons of a continental power. I suggest that the good guys lost. (pp. 135-137)We know what happened next as the three Punic Wars for control of the Mediterranean:
Then were to be fought three great wars; Punic Wars as the Roman authors call them. The first was a long war of attrition over the ownership of colonial lands. In the second war, Hannibal crossed the Alps with his elephants, and the third war ended with the annihilation of the Carthaginian state and people.(p. 137)Once Carthage was defeated, its land and possessions, including the silver mines in Spain. came under the possession of the Romans. The Roman war machine, forged during those Punic wars, allowed it to expand and take over the previous empires and run the entire Mediterranean was a giant free trade zone, creating plentiful niche space for their people:
Once the Italians under Roman government had taken Sicily, and all that had belonged to Carthage, they must have had all the land and resources which their people would need for several generations. Circumstantial evidence supports this. It became Roman policy, for instance, to settle their veteran soldiers with their families on farms in various parts of Italy; a tactic useful to Rome because it helped forestall possible rebellion from former enemy city states, as well as contenting such potentially dangerous citizens as veteran soldiers.
But it also suggests that there was land to spare for making new farms; the population had not yet expanded to fill up the space made available by conquest of barbarian lands. Yet social habits do not easily change. The free citizens of Rome, which meant the rulers and the middle class of a slave-owning state, had created an army and invented an unbeatable military technique because they needed to go to war to support their standard of life. Now the need was, for a time, assuaged. But the instrument was made and the habits for war were made too. Foreign wars had proved an excellent way of finding opportunity for Roman rulers, soldiers and merchants; they gave promise to the younger sons. War also made the proletariat happy with glory and loot, and it brought regular supplies of slaves to support middle class living, as well as plunder, which could be taxed. War was the great provider of niche-space to those in power at Rome; this is the explanation for the rapidity of the Roman conquests of all the Mediterranean lands which was to follow. (p. 151)Aggressive war became a way of life, and the Roman Empire seemed to be eternal to the people living under it:
Carried on by the weight of tradition, which now decreed that aggressive war was a way of Roman life, the unbeatably deadly legions were then thrust in all directions as far as they could be supported by the logistic techniques and the communications of the times. It took only a matter of decades to do this until the Roman Empire, as we Know it on the maps, was made.
These immense possessions stolen for the Roman people by the legions now gave extraordinary possibilities for the Roman way of life. Much of the Empire, the whole of what is now France for instance, had been used only for barbarian living, a pleasant enough way of life but one which ensured that populations would be much lower than could be sustained from city granaries and advanced agriculture. Here was room for the younger sons to found new estates of their own; there was land to be made into farms for old soldiers back from the wars. Even with a bounding birth rate, it would be some generations before the pinch of land hunger would be felt. The Roman niche could broaden and the Roman numbers could grow for some time without serious consequence or worry. This is the fundamental reason why the Roman Empire lasted so long. The Romans were more fortunate than the Greeks of Alexander's day who had used their military superiority only to conquer filled-up civilized lands, where there was little room to expand.
But Rome owned this vast territory only because her field army was unbeatable by any military force then in existence. Alexander had been able to spread the Greek way of life among the people he conquered because their experience of earlier civilization told them it was good. But the city ways did not seem good to free barbarians bludgeoned into the Roman state. The expanding Romans of the expanding Roman niche took away the means for barbarian living, as surely as the European farmers of North America made it impossible for an American Indian to live a stone age life. Again and again, people driven to despair turned on the occupiers, even though it always meant they would be butchered by a legion in the end. And the turmoil, in great possessions held only by force, meant that the Romans had to leave their government to those who wielded the military power. Via civil war and temporary arrangements the once free Roman constitution fell, as it had to, beneath central dictatorship. (pp. 152-154)
Everywhere the power of irresistible military force prevailed until at last there came an imposed and universal peace in the lands round the Mediterranean Sea, and it happened that a succession of clever and well-meaning men, the Antonines, became emperors of Rome. Under the Antonines Rome entered what is said to have been a golden age, a time of flourishing prosperity and universal order, a time to which many historians still look back with a longing tinged with nostalgia.
The lands round the Mediterranean Sea were set apart from the rest of the world by a ring of legions, who stood to their frontier posts like a dike restraining the stormy sea of barbarians outside. And, within the dike, there was a common law, a common currency, straight, paved roads, a central waterway free from pirates, and a system of banks and credits which let commerce, industry and agriculture flourish. It seemed to citizens of those times, as it seems to citizens of the modern prosperous States of the West, that the way had been found to the perpetuation, and even improvement, of the good life for all forever. (pp. 155-156)We already covered some of the signs of collapse dictated by the ecological hypothesis - increasing bureaucracy, increasing taxes on the middle class, budget deficits, imperial overreach, elite overproduction and jockeying for power, stagnant living standards for the majority, depopulation of the countryside, urbanization, restlessness, distraction via welfare and entertainment industries (bread and circuses), political repression and a police state, inflation, debasing the currency, shortages of basic goods, political corruption and self-serving behavior, privatization of the commons, massive gaps between rich and poor, lack of social mobility, establishment of caste systems, civil wars, mass immigration, and so forth:
And so I offer a new explanation for the decline and fall of the Roman Empire. Resources that could be extracted by contemporary technique from the lands the Empire held were not sufficient to offer the broad niche of the middle-class life of a Mediterranean city-state to very many. Rising numbers held within the Empire in cities were a drain on what little economic surplus the Empire could produce, both from the direct needs of welfare payments and from the costs of the police apparatus needed to control these masses in poverty. There was neither the hope nor the surplus wealth needed for a large army of high-technology soldiers, as there had been in the days of the old Greek and Roman republics when the expansion started. The defenses of the long frontiers faltered and then distant peoples, needing land rather than civilization, pressed their war bands equipped with contemporary armament into the border provinces.
Although the Empire of the West was struck down by force of arms in this way, the real defeat can still be read in terms of breeding strategy, numbers, and niche. The growth of Greek and Roman city-states into an empire was fueled by expanding niche and the promise of more. The resulting empire filled with people until the promise of expanding niche could not be met—a direct consequence of the Roman failure to develop techniques which could extract resources fast enough to provide large niches for many. In this sense, the Empire was crowded, and the fact that there were thinly settled provinces is irrelevant. Having relapsed into a police state with very high maintenance costs, the Empire found it hard to defend itself. And it fell.
As the Roman empire declined, the barbarians, needing new land came and took it over:
With the Roman power gone, the Gothic tribes spread into every country on the European side of the Mediterranean. Some even crossed into Africa. They came with their wives and children to stay, a mass migration of people, for they were under the pressure of crowding in their traditional lands. These traditional lands, in turn, were being pressed upon by other overcrowded barbaric and nomadic peoples from the central Asian steppes. The need for land by these technocratic Gothic barbarians in the suits of armor was apparently overwhelmingly great and they found it in the territories which had once been Roman.
They found some land thinly populated because abandoned in strife, or because it was awkwardly placed to supply the needs of cities. Other lands had few people because given over to cattle raising, which needs only a small local population of animal caretakers. The really good farmlands were organized to feed distant cities and so were lived on by populations much smaller than those they actually fed. All these lands the barbarians could settle and use directly, leaving the Roman townsfolk to privation. (pp. 175-177)The empty and depopulated lands of the former Roman Empire were ripe for the picking by the new peoples of the frontier:
The barbarians had come to live in a barbaric way, but they found that they had conquered countries laid out for the life of settled agriculture, and with fine buildings which it was sometimes tempting to use. For generations their ancestors had been able to see what Rome had, and sometimes to plunder a little of it for themselves. Now all was theirs. They began to settle on their conquests rather than to wander around them. And they had, from the start, to fight to keep what they had won lest it be taken from them by other barbarians, like the Huns, pressing on their heels from a population crush in the steppes to the east. Their armored horsemen found themselves defending the very lines which the legions had once held. And behind the new dike of mailed horsemen they began forging the Christian and feudal kingdoms out of which were to grow the modern civilization of the West.
But in North Africa things were very different. The fertile grain fields which had once fed the city of Rome were but patches of land on the edge of vast and unproductive deserts. And in the deserts and semideserts in a great arc of land, from the edge of the empire in Asia to the Atlantic Ocean, were the wandering barbarian tribes who had always lived there. These people had pressed hard upon their resources since long Carthage, and their ways of life had changed very little. They were always warlike, because the necessities for life were so scarce that they must ever be ready to defend what they had. But they had never been able to develop anything like the formidable weaponry of the barbarians north of Rome, nor, indeed, any military technology beyond that suited for the swift raid across the desert.
They traveled light on nimble horses, without armor, and fought in swift onslaughts when the blood was up, with lances and swords. They had never been able to stand against the regular soldiers of Rome, or Carthage before her, though they had been a nuisance to both states and had also sometimes been employed by both as auxiliary cavalry, They seemed in no condition to do with the Roman Empire of the south what the armored Gothic barbarians had done to the Roman Empire of the north. Yet the crowding of some of these people into wretchedness in the country of Arabia was preparing the way for fresh aggressive wars of conquest with results no less remarkable. (pp. 179-180)
The eruption of warriors from the desert, which Muhammad uncorked like a genie from his Arabian bottle, was yet another of the wars of aggression started because the people needed land. There seems to have been no new military technology behind this aggression; the faithful merely fought as clouds of gallant horsemen, as they had always done. But then there was no longer a phalanx or a legion in North Africa to withstand them. As the Arabians began to succeed, the tribes of all the deserts joined them, with what perhaps may be best described as holy glee. The Christian populous societies of the fertile patches along the coast had not the spirit, or the organized purpose, to stand against this deliberate fury. They were conquered, oppressed, enslaved, and sometimes subjected to that final solution of "being driven out." Their onetime resources went to support the swelling numbers and swelling desires of the people who had embraced this new niche called "Islam." In about a century all the former African possessions of Rome were in the power, and under the command, of the once barbarians of the desert, who were taking over the settlements in their own way and building from them an entirely new civilization. (pp. 181-182)
After Leo had defended Constantinople and Charles had defended France, the Mediterranean Sea became a division between the Moslem peoples of North Africa and the Christian peoples of Europe. Both civilizations were to develop in their own way, and although they were often to fight one another, the essential boundary between their lands was never changed. The peoples round that land-locked sea would never again be linked by common laws and common languages. The Mediterranean Episode was over. (pp. 183-184)I'm kind of surprised he does not mention the Crusades, which seems to confirm the hypothesis--Europe was undergoing a huge youth population bulge at the time during the High Middle Ages, all of the lands that could be settled were settled, and it's generally accepted historical fact that the ambitions of younger prices, who did not inherit the lands as their older brothers did, was a driving force in answering the Pope's call to conquer the lands of the "infidels."
The next chapter presents an interesting hypothesis. It has long been known that periodic waves of nomadic horsemen have overrun settled civilizations since ancient times. The settled agricultural civilizations of the ancient Near East, those of Ancient Greece, the empires of China, and the Islamic empires have all faced down these waves. It is a major factor in world history.
We know most about the attacks which were most recent, about those of the Mongols and their Genghis Khan and his successors between six and seven hundred years ago... But we have evidence for the intermittent eruption of nomad armies from the steppes for as far back as our written records show...The afflictions seemed to come in waves, there being a few generations when the soldiers of civilized states had to fight again and again for the existence of their countries against armies of people who appeared from regions beyond the knowledge of their geography.
A century or two of repose would follow, when the wounded civilizations could rebuild their shattered confidence and shattered frontiers, or win back the border territories which the horsemen had entirely taken from them...To Europeans the main floods of the last three thousand years have been associated with the names of Scythians, Sarmatians, Huns, Magyars and Mongols, though there were many other tribes and races involved in the mass movements...
The sense of periodicity...is even more striking when the history of assaults on China and India is compared with it. They too were struck by Mongols, Huns and the rest, and at the same time. The great lozenge of land which is the Eurasian steppe stretches all the way from China to Europe, having a frontier with each great center of civilization in turn. It is a single geographic feature; as it were, a giant piece of real estate jointly owned by an assembly of nomadic tribes...Yet the cyclic ebb and flow of armies coming out of the steppes is apparently real, requiring an explanation. (pp. 186-189)Some have argued that these waves of conquest were due to climatic fluctuations - warmer and wetter years on the steppe led to expansion and the establishment of empires. Colinvaux rejects this answer. Yet his explanation does involve climate--in a way.
Colinvaux argues that these periodic waves are due to a breeding strategy on the part of the steppe nomads. When years were good, people adjusted their breeding strategy and had more children. When the climate of the steppe turned sour and times got tough, these warlike people, accustomed to techniques of fighting among themselves and able to live off the land effectively, took to their horses to seek out new lands to conquer.
Colinvaux sees the perfect analogy for this periodic overrunning of settled civilizations in the breeding habits of one particular animal - the arctic rodent known as the lemming, which goes through periodic bursts of population and then fades away until the next population explosion:
Nomads of the Asian steppes lived under conditions and in ways which give a distant echo of the lemmings. They were adapted to life where there were no trees and where there was a long hard winter. They were dependent on their animals for food, transport, clothing, and even for the covering of their houses. They managed quick crops of grain when the rains came. They learned to wander far with the changing seasons, to distant pastures, to water holes. In their wanderings they were able to live off their animals, which were a moving commissariat and larder, and on grain, carried in sacks and saddle bags...
Yet the nomad niche on the steppes was one that could not support dense populations. They ate meat and a little corn, both depending on the poor productivity of the steppes for forage and grain. Niche-spaces must usually have been at a premium on the steppes. So we have a chronic shortage of niche-spaces and an abundant supply of young adults to compete for them; few jobs and many applicants, the nomad cultures must have ways of allotting niche-spaces to some and denying them to others...
But the fortunes of such people were critically dependent on the weather, particularly on the amount and timing of the seasonal rains. There are wet years and dry years on the steppes, as the weather changes with that characteristic unpredictability which we all know so well...Because the rains were fickle, however, the niche that the people of the steppes had learned must be adapted to cope with bad years and good. ..and all the tribes would be over huge areas at once, and all the tribes would be affected equally; they would all wander less in a good year, more in a bad...The breeding strategy of these nomad people would reflect, in detail, this niche of nomad living. Each couple would raise the optimum number of children that they could carry with them and nurture through the lean season. This optimum would certainly be a large number. The nomad niche held none of the restraints that make the wealthy of civilized states opt for small families, nor did nomads feel the privations of poor agricultural peasants or people in city slums who cannot afford to raise many children...
All that is needed to produce a surplus of nomads across all the steppes at the same time is for some run of seasons to encourage societies everywhere to let in a few more adults, because these extra couples would each rear a new family. Perhaps a chance run of good years would do this simply by letting the people wander less so that friction between distant tribes was less, or it could be simply that the herds grew, the mares gave more milk, and the grain sacks were filled. But any small change in habit that let the average recruitment to the tribe at puberty be slightly more generous, would ensure that the steppe would be crowded in the years ahead—especially if the new laxer habits were not easily abandoned...
In this way the whole steppe would start filling with too many people, synchronously, because habit was triggered by weather just as the tundra of large areas can fill with lemmings. People grow and reproduce more slowly than lemmings, and the chances of weather that affect them take longer to work themselves out. That a nomad high should happen only every five hundred years or so by these means seems reasonable.
Population highs of nomads must now be translated into armies of aggression, which is easy. Nomadic people fight over pastures and water holes anyway; more nomads on the move means more fighting in bad years; more fighting means better attention to weapons and generals; and this means the chance of raising a real army. (pp. 197-200)
Population cycles of steppe-people as well as of lemmings are thus synchronized by weather, although they are definitely not caused by cycles in climate. Both lemmings and people use weather as cues for behavior, the lemmings for simple sex, the people more subtly. All people behave to suit the weather but pastoral nomads are more closely tied to weather than the rest of us so that small changes in habit bring large consequences in population.
Yet the climatic pattern of good years and bad is purely random, for both people and lemmings. The length of time between one population high and the next is, for both species, set by how fast each can breed, how long each lives, and how prompt each is to respond to changes in the weather. Lemmings can raise a baby in six weeks, live a year, and produce huge populations at roughly four-year intervals. People take twenty years to raise a baby, live sixty years, and produce largish populations roughly every five hundred years. The cycles are thus properties of the animals, not of climate.
When there are too many lemmings on the tundra, the surplus must die, or fail to breed, so that the excess crop is removed. The same is true for nomads. Surplus nomads are spent as they follow their great captain in his armies to pitch their tents in border lands once held by civilized states. The steppes are relieved of their surplus people and nomadism there may revert to its traditional ways...Fighting is no longer so necessary to the stay-at homes and the martial needs of the people which made them submit to the triumphant discipline of their generals can be relaxed. This explains the ebb tide of nomad conquests...In this way does the ecological hypothesis provide a rational explanation for the periodic wars of conquest undertaken by nomadic peoples... (pp. 202-203)
The nomad armies were never beaten. In the end they merely faded away. Like the decline of more conventional empires, this has often been seen by moralists as the result of a loss of spiritual purpose in the descendants of the conquerors. They grow soft, take to loose living, wallow in their harems, and forget that the martial graces are supposed to be superior. But such moralizing is not necessary to explain the ebb of the Mongol aggressions. The need, which had caused the people to throw up that dreadful army, had been satisfied. The wars had first diverted the frustrations of a rather crowded people with adventure and plunder, and then had removed the cause of those frustrations entirely by effecting an armed emigration. (p.210)Colinvaux includes a chapter commenting on the American Revolution. His description of differing concepts of "freedom" - those of settled, crowded civilizations, and those of a wide open frontier are worth considering:
That England was an island state, densely populated, but with both numbers and opportunities for life expanding. The English had turned their island into a productive garden, with little wildness left. Agriculture, industry and commerce were each collecting into large scale enterprises. It was a society in which the younger sons of the better-off were already taking to trade and foreign adventure, achieving broad niches by the use of other people's lands. And the people had fashioned lies of law and government suited to their tightly organized garden of an island.
The niches in which these English people lived reflected the organization of their developed state. The English who stayed at home expected their futures to be narrowly circumscribed. There was a place for each in society, but little choice of place. It was a society of castes, liberal by the standards of many a caste system, but a society of master and man nevertheless.
Yet the English were thriving on the new developments in agriculture and industry. The optimum family size was large for all classes and the population tended to grow rapidly. This rise in the numbers of the English is well documented. The English themselves knew what was happening, and they were alarmed lest their prosperity might be undermined thereby. Contemporary writers set down the dilemma and one of them, Richard Eburne, showed that salvation was to be found in the mass export of people to colonies.
The English in America brought with them that English concept of freedom under the law, complete with deference to authority and restrictions on behavior appropriate to life in a full-up island laid out like a garden. American elders read of the island life, some were homesick for it, and others learned about it from the regular flow of immigrants who brought it with them. But the way of life, the niche, found to be so satisfactory for England was not so appropriate to Englishmen in America. Why accept the social system which had been found necessary for a well-peopled garden? Here there was room for everyone to do as they pleased, respecting their neighbor perhaps, but not neatly fitted into a neighbor's affairs as the English in England were. Why be master and man when there was room for everybody to be master? A new form of liberty was possible in which each could pursue happiness with much less deference to vested interest. Gradually the niche of an American took shape, described though it was in the language of England.
Niche faced niche across the British muskets in Boston; a niche suited for a crowded island and a niche suited to the almost unlimited possibilities of a new continent. Both peoples used the words "freedom" and "liberty" when they described their purpose, and, hence, the niches they were to preserve. But the British talked of the regulated freedom of a complex society wherein choice was necessarily limited by the numbers of other people needing their shares, and the Americans talked of the much wider freedom possible when opportunity and resource were virtually unlimited. (pp. 219-223)Indeed, we see this in the rallying cry of "freedom" in the United States - the freedom to consume as much as we want and to do as we please, everyone else be damned. It's worth noting that America's period of imperial colonial expansion--the Spanish-American War--occurred almost immediately after the frontier was declared "closed" and "settled." And when that was no longer possible, we entered the technological "frontier" - the vast expansion of niche space through the development of technological marvels such as electricity and the internal combustion engine. Frederick Jackson Turner's "Frontier Thesis" is an elucidation of these ideas.
After World War Two, America alone was the global superpower, able to divert a quarter of the world's resources to itself while the rest of the industrial powers were reduced to rubble. As Morris Berman points out, Americans have always had some sort of frontier and are conditioned to rising living standards in perpetuity, unlike other cultures. This gives a great insight into the American character.
Americans are now freaking out because rising numbers mean that we can no longer do as we please. As numbers rise, new bureaucracy crops up to deal with rising numbers. Social mobility--long considered a birthright--stagnates and degenerates into a rigid caste system (enforced today by the university-educational complex). Americans are living in smaller houses, turning down the thermostats, driving smaller cars, and tightening their belts, all while being told that their wastefully obscene living standards are unsustainable, as indeed they are. This is leading to recrimination and blame, as numerous conspiracy theories such as "Agenda 21" can attest. It is not conspiracy, but the fact of rising numbers, and other nations finally being able to contest for those resources.
Now, frustrated American are aghast at the possibility that may have to live like "Europeans," in apartment blocks without acre-size lawns and riding lawnmowers (i.e. like the rest of the world). They occupy government buildings to protest "tyranny" of having to pay grazing fees to use public land. They stockpile guns and ammunition to defend their "freedom." and use them to menace government officials who come to install energy-efficient smart meters. They balk diverting funds to public transportation rather than expansive freeways for private automobiles, denouncing this as "socialism." They belch coal smoke from their oversized vehicles to protest the adoption of energy efficiency measures and solar power. Politicians constantly rail against taxes and regulations that people of other nations simply see as their civic duty, while fulminating about "freedom" and "liberty."
Is it any wonder that it is primarily Americans who are are devoted to the idea of someone coming up with a solution to all of the world's problems via some sort of technology developed "in their garage," or with getting off "this rock" and colonizing Mars and outer space?
If there is a major flaw in this portion of the book, it is his focus on Western civilizations to the detriment of Eastern cultures, especially China. This most likely is because the book was published in 1980, coincidentally around the same time as the beginning of China's rise to world power status. Because of this, much less was commonly known about China's ancient history by Westerners and there was less scholarship on this point, which is probably why Colinvaux does not devote much discussion to it.
Which is too bad, because China's history is an even greater confirmation of his ecological hypothesis. China has always acutely felt the weight of rising numbers and crowding--indeed I would argue that this is the central pivotal fact of Chinese history. China would consistently bump against a civilizational plateau due to increasing numbers, and would collapse down to a lower level. Unlike the West, they were unable to break through this plateau through technology or colonization; indeed China was famously insular and solipsistic. This led to caste systems and cultural stagnation, as Colinvaux describes. In fact, Ancient Chinese historians were among the first to describe their history in terms of repeating cycles in books such as the Shujing, or "Classic of History."; describing what they called the "Dynastic Cycle."
China's rise since 1980 has seen the ecological hypothesis playing out in a nutshell: rising numbers, rapid growth and industrialization creating new wealth and new niches, repressive government, abandonment of the countryside and flight to the cities even as numbers increase (slower in China due to the one-child policy), concentration of wealth, and now, potentially, imperial expansion and diaspora. That fact that China has tracked the ecological hypothesis so closely since the book was written--something Colinvaux could not have foreseen in 1980--is an impressive confirmation of the book's central thesis.
Another important omission is the impact of rising numbers on ecological degradation and the use of fossil fuels and technology for growth, which has been a central fact in world history since at least the nineteenth century. This is odd, especially in a book purporting to use ecology to explain the historical process (the passage above about Athens is an exception). In his concluding chapter, however, Colinvaux does address some of these issues.
NEXT: Colinvaux's conclusions.