Everyone who has studied the prehistory of human society agrees that the emergence of civilization in different parts of the world was a major event in human adaptation. The world civilization has a ready¸ everyday meaning. It implies “civility¸” a measure of decency in the behavior of the individual in a civilization. Such definitions inevitably reflect ethnocentrism or value judgments because what is “civilized” behavior in civilization might be antisocial or baffling in another. These simplistic understandings are of no use to students of early civilizations seeking definitions and cultural processes.
Today¸ archaeologists use the term civilization as a shorthand for urbanized¸ state–level societies. Those described in these pages are sometimes called “preindustrial civilizations¸” because they relied on manual labor civilizations ¸ but the following features are characteristic of all of them¦
- Societies based on cities¸ with large very complex social organizations. The pre industrial civilization was invariably based on a larger territory such as the Nile Valley¸ as opposed to smaller areas owned by individual kin groups.
- Economies based on the centralized accumulation of capital and social status through tribute and taxation. For instance¸ Sumerian kings in Mesopotamia monopolized trading activity in the name of the state. This type of economy allows the support of hundreds¸ often thousands¸ of nonfood production such as smiths and priests. Long–distance trade and the division of labor¸ as well as craft specialization's ¸ are often characteristic of early civilizations.
- Advances toward formal record keeping¸ science¸ and mathematics¸ and some form of written script. This took many forms¸ from Egyptian hieroglyphs to the knotted strings used by the Inca of the Andes.
- Impressive public buildings and monumental architecture¸ like Egyptian temples and Maya ceremonial centers.
- Some form of all—embracing state religion¸ in which the ruler plays a leading role. For example¸ the Egyptian pharaoh was considered a living god on earth.
Cities
Archaeological research into early civilization concentrates on the origin and development of the city. Today the city is the primary human settlement type throughout the world¸ and it has become so since the industrial revolution altered the economic face of of the globe. The earliest cities assumed many forms¸ the compact¸ walled settlement of Mesopotamia to the Mesoamerican ceremonial center¸ with a core population in its precincts and a scattered rural population in villages arranged over the surrounding landscapes. The places of the Minoans and Mycenaeans of Crete and mainland Greece functioned as secular economic and trading centers for scattered village populations nearby.
A city can be defined by its population¸ which is generally larger and denser than that of a town or a village. A generally used rule of thumb is a lower limit of 5¸000 people for a town or village. However¸ numbers are not a sufficient definition. Economic and organizational complexity as well as population size and density distinguish the city from other settlement types ¦
A city is a large and relatively dense settlement¸ which a population numbered in at least the thousands. Small cities of the ancient world had 2000 or 3000 inhabitants; the largest such as Rome or Changan in China¸ may have had over a million.
Cities are also characterized by specialization and interdependence, between the city and its rural hinterland, and between specialist craftspeople and other groups within the city. The city is a central place in its region, providing services for the villages of the surrounding area, at the same time depending on those villages for food. Most cities¸ for example¸ had a marketplace where agricultural produce could be exchanged.
Cities also have degree of organizational complexity well beyond that of small farming communities. There are centralized institutions to regulate internal affairs and ensure security. These usually find expression in monumental architecture such as temples or places, or sometimes a city wall. Here we must recognize an overlap between the concept of the city and the concept of the state. Centralized institutions¸ too, characterize states. It may be possible to have states without cities¸ but is hard to envisage a city that was not embedded within a state.
An ancient city site will usually be obvious to archaeologists¸ from both its size and the scale of its remains. The state is more difficult to define. It is a political unit governed by a central authority whose power crosscuts bonds of kinship. Kin groups do not disappear, of course¸ but their power is reduced¸ and a new axis of control emerges based on allegiance to a ruling elite.
Theories of the Origins of States
Few developments in the world prehistory have generated as much theoretical debate as the origins of states. Modern hypotheses build on theories developed as early as the 1930´s.
The "Urban Revolution"
The Victorians¸ like the Greeks and Romans before them, assumed that civilization had originated along the Nile¸ in the “Land of the Pharaohs.” Eventually, early theorizing used a broader canvas¸ embracing all of the Fertile Crescent.
Vere Gordon Childe of “Neolithic Revolution” fame formulated the first relatively sophisticated theories about the origins of civilizations. He wrote of a later “Urban Revolution¸” which saw the development of metallurgy and the appearance of a new social class of full–time artisans´ and specialists¸ who lived in much larger settlements cities. However¸ the artisans´ products had to be distributed¸ and raw materials obtained¸ often from long distances away. Both needs reduced the self–sufficiency of peasant communities¸ Childe argued. Agricultural techniques became more sophisticated¸ as a higher yield of food per capita was needed to support a growing nonagricultural population. Irrigation increased productivity¸ leading to centralization of food supplies¸ production¸ and distribution. Taxation and tribute led to the accumulation of capital. Ultimately¸ said Childe¸ a new class–stratified society came into being¸ based on economic classes rather than traditional ties of kin. Writing was essential for keeping records and for developing exact and predictive sciences. Transportation by land and water was part of the new order. A unifying religious force dominated urban life as priest kings and despots rose to power. Monumental architecture testified to their activities. Gordon Childe considered technology and the development of craft specialization in the hands of full–time artisans a cornerstone of the Urban Revolution.
Early Ecological Models
With much more data to work with, modern scholars now agree that three elements of Gordon Childe´s “Urban Revolution” were of great importance in the development of all the world´s early civilizations ¦ large food surpluses¸ diversified farming economics¸ and irrigation agriculture.
The Fertile Crescent model assumed that the exceptional fertility of the Mesopotamian flood plain and the Nile Valley was the primary cause for the appearance of cities and states in these regions larger grain surpluses resulted from increased agricultural efficiency¸ as well as social and cultural changes. Some scholars¸ among them the economist Ester Boserup¸ took the opposite tack. They believed that population growth¸ not food surplus¸ was the incentive for the intensified agriculture and eventually more complex societies. However¸ through important¸ dense population did not characterize all state–organized societies¸ as the Mycenaean or Inca civilizations show.
The same theorists pointed out how the ecological diversity of local environments varied greatly from one area to another. Diversified agricultural economies tended to focus on fewer¸ more productive crops¸ but the ultimate subsistence base remained wide. For instance¸ the Egyptians farmed wheat and barley on a large scale¸ but also raised large herds of cattle and goats. The highland Andean states relied heavily on their lowland neighbors for fishmeal¸ cotton¸ and other recourse. The resulting diversity of food recourse protected the people against famine and stimulated trade and exchange for food and other products¸ as well as the growth of distributive organizations that encourage centralized authority.
The adoption of irrigation agriculture was also considered a major factor in the rise of civilization since it supported far higher population densities. Early ecological theories were closely tied to the apparent widespread use of irrigation agriculture by early states to enhance agricultural output. Anthropologists Julian Steward and historian Karl Wittfogel argued during the 1950s that irrigation lay behind the development of socially stratified societies in Egypt¸ Mesopotamia¸ and elsewhere¸ which Wittfogel famously called “hydraulic civilizations.” In areas where irrigation was practiced, both scholars argued, the relationship between the environment, food production, and social institutions was identical. Wittfogel was a Chinese specialist¸ who owed their despotic control over densely populated areas by large–scale water control projects in areas of scant rainfall. Thus¸ the social requirements of irrigation led to the development of states and urban societies in several parts of the Old World¸ and the same requirements led to remarkable similarities in their economic and social structure.
A mass of new data¸ including large–scale surveys¸ has sharpened our perceptions of early irrigation. For example¸ archaeologist Robert Adams carried out major field surveys of ancient irrigation works in Mesopotamia in the 1960s. Adams found that early Mesopotamian irrigation consisted of cleaning natural river channels and building just a few smaller feeder canals. Most settlements lay near major rivers and make the most of the natural hydrology of the water ways. Each community controlled its own small–scale irrigation schemes on a massive scale. The same was true of Egypt¸ where the greatest irrigation works were undertaken during the New Kingdom¸ using thousands of laborers fulfilling tax obligations to the state. In contrast¸ early Egyptian agriculture relied on natural basins to hold back Nile water¦ a village–level¸ small–scale operation requiring no official supervision.
While some form of irrigation was a necessary precondition for the settlement of the southern Mesopotamia plains¸ where the world's first cities arose¸ large scale–irrigation dose not everywhere appear to have been a factor in the rise of early civilizations. However¸ by some token¸ modern researchers have shown that ecology was only one component in a mosaic of many changes that led to state–organized societies.
Technology and Trade
The origins and evolution of complex societies have long been linked to technological innovations and to growing trade in raw materials like obsidian¸ copper¸ and luxuries of all kinds. Gordon Childe considered metallurgy an important component in the Urban Revolution¸ but¸ in fact¸ copper and other exotic materials were at first used in southwest Asia for small–scale production of cult objects and jewelry. In many cases the technological innovations that did appear¸ like the wheel in Mesopotamia and the sailing ship in Egypt¸ were of more benefit in transportation that production. Not until several centuries after civilizations started were copper and bronze more abundant as demands for transportation and military needs burgeoned. Technology did evolve¸ but only in response to developing markets¸ new demands¸ and the expanded needs of a tiny segment of the population—the elite.
Any form of trade involves two elements¸ both the goods and commodities being exchanged and the people doing the exchanging. People make trade connections when they need to acquire goods and service that re not available to them with their local area. This trade (more conventionally called “exchange”) can be gift giving, the exchange of gifts that reinforce a social relationship between both individuals and groups as a whole. The gifts serve as gestures that place obligations on both parties and are often a preliminary to bartering for all manner of commodities. This kind of preliminary gift exchange is commonplace in New Guinea, and the Pacific and was widespread in Africa during the past 2¸000 years. Bartering¸ the exchange of common commodities or goods¸ was another basic trading mechanism for man thousands of years¸ often sporadic¸ and usually based on motions of reciprocity¸ the mutual exchange of commodities or objects between individuals or groups. Redistribution of these good through society lay in the hands of chiefs¸ religious leaders¸ or kin groups. As we have seen¸ such redistribution was a basic element in chiefdoms. The change from redistribution to impersonal market economy trade¸ often based on regulated commerce¸ involving perhaps fixed process¸ even currency¸ was a change closely tied to growing political social complexity and hence to the development of the state.
In the 1970s¸ a number of archaeologists gave trade a primary role in the rise of states. In the Aegean area, British archaeologists Colin Renfew attributed the dramatic flowering of Minoan civilization on Crete and through the Aegean to intensified trading contacts and to the impact of olive and vine cultivation on local communities. As agricultural economies became more diversified and local food supplies could be purchased both locally and over long distances¸ a far–reaching economic interdependence resulted. Eventually¸ this led to redistribution systems for luxuries and basic commodities¸ system that were organized and controlled by Minoan places and elsewhere in the Aegean where there were major centers of olive production.
Now that we know much more about ancient exchange and commerce¸ we know that trade can never be looked upon as a unifying factor or as a primary cause of ancient civilization¸ simply because no one aspects of it was an overriding cause of cultural change or evolution in trading practices. Extensive long–distance trade¸ like large–scale irrigation¸ was a consequence rather than a cause of civilization.
Science
OBSIDIAN SOURCING
Scientists studied the sources of toolmaking stone before the advent of spectrographic analysis¸ relying both on petrology and on distinctive rocks, like the butter–colored and easily recognized Grand Pressigny flint¸ widely used in France by Stone Age farmers. Hi–Tech analytical methods have revolutionized sourcing since the 1960s¸ when British archaeologists Colin Renfrew and others used spectrographic analysis to identify no fewer than 12 early farming villages that had obtained from the Ciftlik area of central Turkey. This pioneer study showed that 80% of the chipped stone villages within 186 miles (300 Kilometers) of Ciftlik was obsidian. Outside this “supply zone¸” the percentages of obsidian dropped away sharply with distance¸ to 5% in a Syrian village and 0.1% in the Jordan valley. If these calculations were correct¸ each village was passing about half its imported obsidian further down the line. Renfew and his colleagues identified no fewer than nine obsidian “interaction zones”
Between Sardinia and Mesopotamia¸ each of them linked to well–defined sources of supply¸ each yielding obsidian with its own distinctive trace elements identifiable spectrographically.
Warfare
In the 1970s¸ anthropologists Robert Carneio used the archaeology of coastal valleys in Peru to argue that warfare played a key role in state formations. His “coercive theory” of state origins argued that the amount of agricultural land in these valleys was limited and surrounded by desert. So a series of predictable events led to the development of states. At first¸ autonomous farming villages flourished in the valley landscapes. However¸ as the population grew and more land was taken up, the communities started fighting over land and raided each other´s fields as they competed for limited acreage. Some of the village leaders emerged as successful warlords¸ became chieftains¸ and presided over large tribal polities. The valley population continued to grow¸ and warfare intensified until the entire region fell under the sway of a single¸ successful warrior¸ who presided over a single state centered on the valley. Then this ambitious ruler and his successors start raiding neighboring valleys. Eventually a multi–valley state developed¸ creating a much larger civilization.
Carneio´s theory is hard to test in the field¸ but an attempt to do so in Peru´s Santa valley showed no sign of autonomous villages. Rather¸ it depicted a much more complex¸ evolving settlement pattern over many centuries. Archaeologist David Wilson points out that the only “coercive” process came about around 400 A.C.E.¸ when the Moche people carved out a multi–valley state by military conquest of neighboring valleys. The conquest took place long after complex irrigation–based societies flourished in the Santa valley. As with irrigation hypotheses¸ reality is more complex than the straightforward Carnerio.
Warfare also can be rejected as a primary cause of civilization on other grounds. In earlier times¸ the diffuse social organizations of village communities had not yet led to the institutional warfare that resulted from the concentration of wealth and power in a few hands. There was raiding and violent conflict between kingdoms almost everywhere before state formations¸ which may have had a profound effect on peoples´ lives, but other powerful factors were simultaneously at play. Only when absolute and despotic monarchs came into power did warfare become endemic¸ with standing armies to control important resources¸ solve political questions¸ and ensure social inequality. This type of warfare presupposes authority and is a consequence of civilization.
Cultural Systems and Civilization
Most archaeologists agree that urban life and pre–industrial civilization came into existence gradually¸ during a period of major social and economic change. Everyone agrees¸ also¸ that linear explanations invoking irrigation, trade¸ or warfare are inadequate. Recent theories of the rise states invoke multiple¸ and often intricate¸ causes and are frequently based on systems models.
In the 1960´s¸Robert Adams¸ an expert on ancient Mesopotamia, introduced a new generation of complex theories when he argued that irrigation agriculture¸ increased warfare¸ and “local resource variability” were three factors vital in newly appearing urban civilizations. Each affected society and the other factors with positive feedback¸ helping to reinforce each other. The creation of food surpluses and the emergence of a stratified society were critical developments. Irrigation agriculture could feed a bigger population. Larger populations¸ an increase impermanent settlement¸ and trade with regular centers for redistributing goods were all pressures for greater production and increased surpluses actively fostered by dominant groups in society. The greatly enlarger surpluses enabled those who controlled them to employ larger numbers of artisans and other specialists who did not themselves grow crops.
Adams argued that some societies were better able to transform themselves into states because of the favorable variety of resources on which they could draw. Higher populations led to monopolies over strategic resources. These communities eventually were more powerful than their neighbors¸ expanding their territories by military campaigns and efficiently exploiting their advantages over other peoples. Such cities became early centers of major religious activities¸ of technological and artistic innovations¸ and of writing. Literacy¸ a skill confined to a few people¸ became an important source of power.
Archaeologists like Kent Flannery¸ who works in Mesopotamia¸ now saw the state as a very complicated “living” system, the complexity of which could be measured by the internal differentiation and intricacy of its subsystems¸ such as those for agriculture¸ technology, or religious beliefs. The way these subsystems were linked¸ and the controls that society imposed on the system¸ were vital. This model seemed to work well with Mesoamerican states¸ where pervasive religious beliefs formed close links between public architecture¸ the economy¸ and other subsystems of civilizations.
The management of a state is a far more elaborate and central undertaking than that of a small chiefdom. Indeed¸ the most striking difference between states and less–complicated societies is the degree of complexity in civilizations´ ways of reaching decisions and in their hierarchic organizations¸ not necessarily in their subsistence activities. Systems models of early states are bound to be complex¸ for they have to distinguish between mechanisms and processes of cultural change¸ and the socio–environmental pressures by which we have sought to explain in the regulations of environmental and economic variables in early civilizations¸ and indeed in any human society.
Environmental Change
Ecologically based theories, which also rely heavily on systems approaches, have enjoyed a relatively long life compared with many other hypotheses. For example¸ in a classic study of the Valley of Mexico¸ William Sanders and a group of archaeologists showed how the Aztec state created and organized huge agricultural systems that spread over the shallow waters of the lakes that once filled the valley. The variability of the local environment meant that the Aztecs had to exploit every environmental opportunity afforded them. Thus¸ Sanders argues the state organized large–scale agriculture to support a population of up to 250¸000 in and close to the Aztec capital¸ Tenochtitlán. Environmental factors were decisive in each area where civilizations began, he believes. Another important factor was centralized leadership.
The ecological approach has serious problems. How, for example, does one tell which environments would foster state formations? Fertile food plains like those in Mesopotamia and Egypt. Coastal rivers valleys like those in Peru? Highland plateaus like those of Mesoamerica. Or areas where land is in short supply (also coastal Peru)? States have arisen in regions where there are few geographic constraints, like Maya lowlands of Mesoamerica. Further¸ pre–industrial civilization developed without any sign of rapid population growth¸ in Iran (Persia) and other parts of southwest Asia. However¸ there can be no doubt those environmental factors were major factors in a very complex process of cultural change and response.
Theories of the Origins of States
Few developments in the world prehistory have generated as much theoretical debate as the origins of states. Modern hypotheses build on theories developed as early as the 1930´s.
The "Urban Revolution"
The Victorians¸ like the Greeks and Romans before them, assumed that civilization had originated along the Nile¸ in the “Land of the Pharaohs.” Eventually, early theorizing used a broader canvas¸ embracing all of the Fertile Crescent.
Vere Gordon Childe of “Neolithic Revolution” fame formulated the first relatively sophisticated theories about the origins of civilizations. He wrote of a later “Urban Revolution¸” which saw the development of metallurgy and the appearance of a new social class of full–time artisans´ and specialists¸ who lived in much larger settlements cities. However¸ the artisans´ products had to be distributed¸ and raw materials obtained¸ often from long distances away. Both needs reduced the self–sufficiency of peasant communities¸ Childe argued. Agricultural techniques became more sophisticated¸ as a higher yield of food per capita was needed to support a growing nonagricultural population. Irrigation increased productivity¸ leading to centralization of food supplies¸ production¸ and distribution. Taxation and tribute led to the accumulation of capital. Ultimately¸ said Childe¸ a new class–stratified society came into being¸ based on economic classes rather than traditional ties of kin. Writing was essential for keeping records and for developing exact and predictive sciences. Transportation by land and water was part of the new order. A unifying religious force dominated urban life as priest kings and despots rose to power. Monumental architecture testified to their activities. Gordon Childe considered technology and the development of craft specialization in the hands of full–time artisans a cornerstone of the Urban Revolution.
Early Ecological Models
With much more data to work with, modern scholars now agree that three elements of Gordon Childe´s “Urban Revolution” were of great importance in the development of all the world´s early civilizations ¦ large food surpluses¸ diversified farming economics¸ and irrigation agriculture.
The Fertile Crescent model assumed that the exceptional fertility of the Mesopotamian flood plain and the Nile Valley was the primary cause for the appearance of cities and states in these regions larger grain surpluses resulted from increased agricultural efficiency¸ as well as social and cultural changes. Some scholars¸ among them the economist Ester Boserup¸ took the opposite tack. They believed that population growth¸ not food surplus¸ was the incentive for the intensified agriculture and eventually more complex societies. However¸ through important¸ dense population did not characterize all state–organized societies¸ as the Mycenaean or Inca civilizations show.
The same theorists pointed out how the ecological diversity of local environments varied greatly from one area to another. Diversified agricultural economies tended to focus on fewer¸ more productive crops¸ but the ultimate subsistence base remained wide. For instance¸ the Egyptians farmed wheat and barley on a large scale¸ but also raised large herds of cattle and goats. The highland Andean states relied heavily on their lowland neighbors for fishmeal¸ cotton¸ and other recourse. The resulting diversity of food recourse protected the people against famine and stimulated trade and exchange for food and other products¸ as well as the growth of distributive organizations that encourage centralized authority.
The adoption of irrigation agriculture was also considered a major factor in the rise of civilization since it supported far higher population densities. Early ecological theories were closely tied to the apparent widespread use of irrigation agriculture by early states to enhance agricultural output. Anthropologists Julian Steward and historian Karl Wittfogel argued during the 1950s that irrigation lay behind the development of socially stratified societies in Egypt¸ Mesopotamia¸ and elsewhere¸ which Wittfogel famously called “hydraulic civilizations.” In areas where irrigation was practiced, both scholars argued, the relationship between the environment, food production, and social institutions was identical. Wittfogel was a Chinese specialist¸ who owed their despotic control over densely populated areas by large–scale water control projects in areas of scant rainfall. Thus¸ the social requirements of irrigation led to the development of states and urban societies in several parts of the Old World¸ and the same requirements led to remarkable similarities in their economic and social structure.
A mass of new data¸ including large–scale surveys¸ has sharpened our perceptions of early irrigation. For example¸ archaeologist Robert Adams carried out major field surveys of ancient irrigation works in Mesopotamia in the 1960s. Adams found that early Mesopotamian irrigation consisted of cleaning natural river channels and building just a few smaller feeder canals. Most settlements lay near major rivers and make the most of the natural hydrology of the water ways. Each community controlled its own small–scale irrigation schemes on a massive scale. The same was true of Egypt¸ where the greatest irrigation works were undertaken during the New Kingdom¸ using thousands of laborers fulfilling tax obligations to the state. In contrast¸ early Egyptian agriculture relied on natural basins to hold back Nile water¦ a village–level¸ small–scale operation requiring no official supervision.
While some form of irrigation was a necessary precondition for the settlement of the southern Mesopotamia plains¸ where the world's first cities arose¸ large scale–irrigation dose not everywhere appear to have been a factor in the rise of early civilizations. However¸ by some token¸ modern researchers have shown that ecology was only one component in a mosaic of many changes that led to state–organized societies.
Technology and Trade
The origins and evolution of complex societies have long been linked to technological innovations and to growing trade in raw materials like obsidian¸ copper¸ and luxuries of all kinds. Gordon Childe considered metallurgy an important component in the Urban Revolution¸ but¸ in fact¸ copper and other exotic materials were at first used in southwest Asia for small–scale production of cult objects and jewelry. In many cases the technological innovations that did appear¸ like the wheel in Mesopotamia and the sailing ship in Egypt¸ were of more benefit in transportation that production. Not until several centuries after civilizations started were copper and bronze more abundant as demands for transportation and military needs burgeoned. Technology did evolve¸ but only in response to developing markets¸ new demands¸ and the expanded needs of a tiny segment of the population—the elite.
Any form of trade involves two elements¸ both the goods and commodities being exchanged and the people doing the exchanging. People make trade connections when they need to acquire goods and service that re not available to them with their local area. This trade (more conventionally called “exchange”) can be gift giving, the exchange of gifts that reinforce a social relationship between both individuals and groups as a whole. The gifts serve as gestures that place obligations on both parties and are often a preliminary to bartering for all manner of commodities. This kind of preliminary gift exchange is commonplace in New Guinea, and the Pacific and was widespread in Africa during the past 2¸000 years. Bartering¸ the exchange of common commodities or goods¸ was another basic trading mechanism for man thousands of years¸ often sporadic¸ and usually based on motions of reciprocity¸ the mutual exchange of commodities or objects between individuals or groups. Redistribution of these good through society lay in the hands of chiefs¸ religious leaders¸ or kin groups. As we have seen¸ such redistribution was a basic element in chiefdoms. The change from redistribution to impersonal market economy trade¸ often based on regulated commerce¸ involving perhaps fixed process¸ even currency¸ was a change closely tied to growing political social complexity and hence to the development of the state.
In the 1970s¸ a number of archaeologists gave trade a primary role in the rise of states. In the Aegean area, British archaeologists Colin Renfew attributed the dramatic flowering of Minoan civilization on Crete and through the Aegean to intensified trading contacts and to the impact of olive and vine cultivation on local communities. As agricultural economies became more diversified and local food supplies could be purchased both locally and over long distances¸ a far–reaching economic interdependence resulted. Eventually¸ this led to redistribution systems for luxuries and basic commodities¸ system that were organized and controlled by Minoan places and elsewhere in the Aegean where there were major centers of olive production.
Now that we know much more about ancient exchange and commerce¸ we know that trade can never be looked upon as a unifying factor or as a primary cause of ancient civilization¸ simply because no one aspects of it was an overriding cause of cultural change or evolution in trading practices. Extensive long–distance trade¸ like large–scale irrigation¸ was a consequence rather than a cause of civilization.
Science
OBSIDIAN SOURCING
Scientists studied the sources of toolmaking stone before the advent of spectrographic analysis¸ relying both on petrology and on distinctive rocks, like the butter–colored and easily recognized Grand Pressigny flint¸ widely used in France by Stone Age farmers. Hi–Tech analytical methods have revolutionized sourcing since the 1960s¸ when British archaeologists Colin Renfrew and others used spectrographic analysis to identify no fewer than 12 early farming villages that had obtained from the Ciftlik area of central Turkey. This pioneer study showed that 80% of the chipped stone villages within 186 miles (300 Kilometers) of Ciftlik was obsidian. Outside this “supply zone¸” the percentages of obsidian dropped away sharply with distance¸ to 5% in a Syrian village and 0.1% in the Jordan valley. If these calculations were correct¸ each village was passing about half its imported obsidian further down the line. Renfew and his colleagues identified no fewer than nine obsidian “interaction zones”
Between Sardinia and Mesopotamia¸ each of them linked to well–defined sources of supply¸ each yielding obsidian with its own distinctive trace elements identifiable spectrographically.
Warfare
In the 1970s¸ anthropologists Robert Carneio used the archaeology of coastal valleys in Peru to argue that warfare played a key role in state formations. His “coercive theory” of state origins argued that the amount of agricultural land in these valleys was limited and surrounded by desert. So a series of predictable events led to the development of states. At first¸ autonomous farming villages flourished in the valley landscapes. However¸ as the population grew and more land was taken up, the communities started fighting over land and raided each other´s fields as they competed for limited acreage. Some of the village leaders emerged as successful warlords¸ became chieftains¸ and presided over large tribal polities. The valley population continued to grow¸ and warfare intensified until the entire region fell under the sway of a single¸ successful warrior¸ who presided over a single state centered on the valley. Then this ambitious ruler and his successors start raiding neighboring valleys. Eventually a multi–valley state developed¸ creating a much larger civilization.
Carneio´s theory is hard to test in the field¸ but an attempt to do so in Peru´s Santa valley showed no sign of autonomous villages. Rather¸ it depicted a much more complex¸ evolving settlement pattern over many centuries. Archaeologist David Wilson points out that the only “coercive” process came about around 400 A.C.E.¸ when the Moche people carved out a multi–valley state by military conquest of neighboring valleys. The conquest took place long after complex irrigation–based societies flourished in the Santa valley. As with irrigation hypotheses¸ reality is more complex than the straightforward Carnerio.
Warfare also can be rejected as a primary cause of civilization on other grounds. In earlier times¸ the diffuse social organizations of village communities had not yet led to the institutional warfare that resulted from the concentration of wealth and power in a few hands. There was raiding and violent conflict between kingdoms almost everywhere before state formations¸ which may have had a profound effect on peoples´ lives, but other powerful factors were simultaneously at play. Only when absolute and despotic monarchs came into power did warfare become endemic¸ with standing armies to control important resources¸ solve political questions¸ and ensure social inequality. This type of warfare presupposes authority and is a consequence of civilization.
Cultural Systems and Civilization
Most archaeologists agree that urban life and pre–industrial civilization came into existence gradually¸ during a period of major social and economic change. Everyone agrees¸ also¸ that linear explanations invoking irrigation, trade¸ or warfare are inadequate. Recent theories of the rise states invoke multiple¸ and often intricate¸ causes and are frequently based on systems models.
In the 1960´s¸Robert Adams¸ an expert on ancient Mesopotamia, introduced a new generation of complex theories when he argued that irrigation agriculture¸ increased warfare¸ and “local resource variability” were three factors vital in newly appearing urban civilizations. Each affected society and the other factors with positive feedback¸ helping to reinforce each other. The creation of food surpluses and the emergence of a stratified society were critical developments. Irrigation agriculture could feed a bigger population. Larger populations¸ an increase impermanent settlement¸ and trade with regular centers for redistributing goods were all pressures for greater production and increased surpluses actively fostered by dominant groups in society. The greatly enlarger surpluses enabled those who controlled them to employ larger numbers of artisans and other specialists who did not themselves grow crops.
Adams argued that some societies were better able to transform themselves into states because of the favorable variety of resources on which they could draw. Higher populations led to monopolies over strategic resources. These communities eventually were more powerful than their neighbors¸ expanding their territories by military campaigns and efficiently exploiting their advantages over other peoples. Such cities became early centers of major religious activities¸ of technological and artistic innovations¸ and of writing. Literacy¸ a skill confined to a few people¸ became an important source of power.
Archaeologists like Kent Flannery¸ who works in Mesopotamia¸ now saw the state as a very complicated “living” system, the complexity of which could be measured by the internal differentiation and intricacy of its subsystems¸ such as those for agriculture¸ technology, or religious beliefs. The way these subsystems were linked¸ and the controls that society imposed on the system¸ were vital. This model seemed to work well with Mesoamerican states¸ where pervasive religious beliefs formed close links between public architecture¸ the economy¸ and other subsystems of civilizations.
The management of a state is a far more elaborate and central undertaking than that of a small chiefdom. Indeed¸ the most striking difference between states and less–complicated societies is the degree of complexity in civilizations´ ways of reaching decisions and in their hierarchic organizations¸ not necessarily in their subsistence activities. Systems models of early states are bound to be complex¸ for they have to distinguish between mechanisms and processes of cultural change¸ and the socio–environmental pressures by which we have sought to explain in the regulations of environmental and economic variables in early civilizations¸ and indeed in any human society.
Environmental Change
Ecologically based theories, which also rely heavily on systems approaches, have enjoyed a relatively long life compared with many other hypotheses. For example¸ in a classic study of the Valley of Mexico¸ William Sanders and a group of archaeologists showed how the Aztec state created and organized huge agricultural systems that spread over the shallow waters of the lakes that once filled the valley. The variability of the local environment meant that the Aztecs had to exploit every environmental opportunity afforded them. Thus¸ Sanders argues the state organized large–scale agriculture to support a population of up to 250¸000 in and close to the Aztec capital¸ Tenochtitlán. Environmental factors were decisive in each area where civilizations began, he believes. Another important factor was centralized leadership.
The ecological approach has serious problems. How, for example, does one tell which environments would foster state formations? Fertile food plains like those in Mesopotamia and Egypt. Coastal rivers valleys like those in Peru? Highland plateaus like those of Mesoamerica. Or areas where land is in short supply (also coastal Peru)? States have arisen in regions where there are few geographic constraints, like Maya lowlands of Mesoamerica. Further¸ pre–industrial civilization developed without any sign of rapid population growth¸ in Iran (Persia) and other parts of southwest Asia. However¸ there can be no doubt those environmental factors were major factors in a very complex process of cultural change and response.
Early Ecological Models
With much more data to work with, modern scholars now agree that three elements of Gordon Childe´s “Urban Revolution” were of great importance in the development of all the world´s early civilizations ¦ large food surpluses¸ diversified farming economics¸ and irrigation agriculture.
The Fertile Crescent model assumed that the exceptional fertility of the Mesopotamian flood plain and the Nile Valley was the primary cause for the appearance of cities and states in these regions larger grain surpluses resulted from increased agricultural efficiency¸ as well as social and cultural changes. Some scholars¸ among them the economist Ester Boserup¸ took the opposite tack. They believed that population growth¸ not food surplus¸ was the incentive for the intensified agriculture and eventually more complex societies. However¸ through important¸ dense population did not characterize all state–organized societies¸ as the Mycenaean or Inca civilizations show.
The same theorists pointed out how the ecological diversity of local environments varied greatly from one area to another. Diversified agricultural economies tended to focus on fewer¸ more productive crops¸ but the ultimate subsistence base remained wide. For instance¸ the Egyptians farmed wheat and barley on a large scale¸ but also raised large herds of cattle and goats. The highland Andean states relied heavily on their lowland neighbors for fishmeal¸ cotton¸ and other recourse. The resulting diversity of food recourse protected the people against famine and stimulated trade and exchange for food and other products¸ as well as the growth of distributive organizations that encourage centralized authority.
The adoption of irrigation agriculture was also considered a major factor in the rise of civilization since it supported far higher population densities. Early ecological theories were closely tied to the apparent widespread use of irrigation agriculture by early states to enhance agricultural output. Anthropologists Julian Steward and historian Karl Wittfogel argued during the 1950s that irrigation lay behind the development of socially stratified societies in Egypt¸ Mesopotamia¸ and elsewhere¸ which Wittfogel famously called “hydraulic civilizations.” In areas where irrigation was practiced, both scholars argued, the relationship between the environment, food production, and social institutions was identical. Wittfogel was a Chinese specialist¸ who owed their despotic control over densely populated areas by large–scale water control projects in areas of scant rainfall. Thus¸ the social requirements of irrigation led to the development of states and urban societies in several parts of the Old World¸ and the same requirements led to remarkable similarities in their economic and social structure.
A mass of new data¸ including large–scale surveys¸ has sharpened our perceptions of early irrigation. For example¸ archaeologist Robert Adams carried out major field surveys of ancient irrigation works in Mesopotamia in the 1960s. Adams found that early Mesopotamian irrigation consisted of cleaning natural river channels and building just a few smaller feeder canals. Most settlements lay near major rivers and make the most of the natural hydrology of the water ways. Each community controlled its own small–scale irrigation schemes on a massive scale. The same was true of Egypt¸ where the greatest irrigation works were undertaken during the New Kingdom¸ using thousands of laborers fulfilling tax obligations to the state. In contrast¸ early Egyptian agriculture relied on natural basins to hold back Nile water¦ a village–level¸ small–scale operation requiring no official supervision.
While some form of irrigation was a necessary precondition for the settlement of the southern Mesopotamia plains¸ where the world's first cities arose¸ large scale–irrigation dose not everywhere appear to have been a factor in the rise of early civilizations. However¸ by some token¸ modern researchers have shown that ecology was only one component in a mosaic of many changes that led to state–organized societies.
Technology and Trade
The origins and evolution of complex societies have long been linked to technological innovations and to growing trade in raw materials like obsidian¸ copper¸ and luxuries of all kinds. Gordon Childe considered metallurgy an important component in the Urban Revolution¸ but¸ in fact¸ copper and other exotic materials were at first used in southwest Asia for small–scale production of cult objects and jewelry. In many cases the technological innovations that did appear¸ like the wheel in Mesopotamia and the sailing ship in Egypt¸ were of more benefit in transportation that production. Not until several centuries after civilizations started were copper and bronze more abundant as demands for transportation and military needs burgeoned. Technology did evolve¸ but only in response to developing markets¸ new demands¸ and the expanded needs of a tiny segment of the population—the elite.
Any form of trade involves two elements¸ both the goods and commodities being exchanged and the people doing the exchanging. People make trade connections when they need to acquire goods and service that re not available to them with their local area. This trade (more conventionally called “exchange”) can be gift giving, the exchange of gifts that reinforce a social relationship between both individuals and groups as a whole. The gifts serve as gestures that place obligations on both parties and are often a preliminary to bartering for all manner of commodities. This kind of preliminary gift exchange is commonplace in New Guinea, and the Pacific and was widespread in Africa during the past 2¸000 years. Bartering¸ the exchange of common commodities or goods¸ was another basic trading mechanism for man thousands of years¸ often sporadic¸ and usually based on motions of reciprocity¸ the mutual exchange of commodities or objects between individuals or groups. Redistribution of these good through society lay in the hands of chiefs¸ religious leaders¸ or kin groups. As we have seen¸ such redistribution was a basic element in chiefdoms. The change from redistribution to impersonal market economy trade¸ often based on regulated commerce¸ involving perhaps fixed process¸ even currency¸ was a change closely tied to growing political social complexity and hence to the development of the state.
In the 1970s¸ a number of archaeologists gave trade a primary role in the rise of states. In the Aegean area, British archaeologists Colin Renfew attributed the dramatic flowering of Minoan civilization on Crete and through the Aegean to intensified trading contacts and to the impact of olive and vine cultivation on local communities. As agricultural economies became more diversified and local food supplies could be purchased both locally and over long distances¸ a far–reaching economic interdependence resulted. Eventually¸ this led to redistribution systems for luxuries and basic commodities¸ system that were organized and controlled by Minoan places and elsewhere in the Aegean where there were major centers of olive production.
Now that we know much more about ancient exchange and commerce¸ we know that trade can never be looked upon as a unifying factor or as a primary cause of ancient civilization¸ simply because no one aspects of it was an overriding cause of cultural change or evolution in trading practices. Extensive long–distance trade¸ like large–scale irrigation¸ was a consequence rather than a cause of civilization.
Science
OBSIDIAN SOURCING
Scientists studied the sources of toolmaking stone before the advent of spectrographic analysis¸ relying both on petrology and on distinctive rocks, like the butter–colored and easily recognized Grand Pressigny flint¸ widely used in France by Stone Age farmers. Hi–Tech analytical methods have revolutionized sourcing since the 1960s¸ when British archaeologists Colin Renfrew and others used spectrographic analysis to identify no fewer than 12 early farming villages that had obtained from the Ciftlik area of central Turkey. This pioneer study showed that 80% of the chipped stone villages within 186 miles (300 Kilometers) of Ciftlik was obsidian. Outside this “supply zone¸” the percentages of obsidian dropped away sharply with distance¸ to 5% in a Syrian village and 0.1% in the Jordan valley. If these calculations were correct¸ each village was passing about half its imported obsidian further down the line. Renfew and his colleagues identified no fewer than nine obsidian “interaction zones”
Between Sardinia and Mesopotamia¸ each of them linked to well–defined sources of supply¸ each yielding obsidian with its own distinctive trace elements identifiable spectrographically.
Warfare
In the 1970s¸ anthropologists Robert Carneio used the archaeology of coastal valleys in Peru to argue that warfare played a key role in state formations. His “coercive theory” of state origins argued that the amount of agricultural land in these valleys was limited and surrounded by desert. So a series of predictable events led to the development of states. At first¸ autonomous farming villages flourished in the valley landscapes. However¸ as the population grew and more land was taken up, the communities started fighting over land and raided each other´s fields as they competed for limited acreage. Some of the village leaders emerged as successful warlords¸ became chieftains¸ and presided over large tribal polities. The valley population continued to grow¸ and warfare intensified until the entire region fell under the sway of a single¸ successful warrior¸ who presided over a single state centered on the valley. Then this ambitious ruler and his successors start raiding neighboring valleys. Eventually a multi–valley state developed¸ creating a much larger civilization.
Carneio´s theory is hard to test in the field¸ but an attempt to do so in Peru´s Santa valley showed no sign of autonomous villages. Rather¸ it depicted a much more complex¸ evolving settlement pattern over many centuries. Archaeologist David Wilson points out that the only “coercive” process came about around 400 A.C.E.¸ when the Moche people carved out a multi–valley state by military conquest of neighboring valleys. The conquest took place long after complex irrigation–based societies flourished in the Santa valley. As with irrigation hypotheses¸ reality is more complex than the straightforward Carnerio.
Warfare also can be rejected as a primary cause of civilization on other grounds. In earlier times¸ the diffuse social organizations of village communities had not yet led to the institutional warfare that resulted from the concentration of wealth and power in a few hands. There was raiding and violent conflict between kingdoms almost everywhere before state formations¸ which may have had a profound effect on peoples´ lives, but other powerful factors were simultaneously at play. Only when absolute and despotic monarchs came into power did warfare become endemic¸ with standing armies to control important resources¸ solve political questions¸ and ensure social inequality. This type of warfare presupposes authority and is a consequence of civilization.
Cultural Systems and Civilization
Most archaeologists agree that urban life and pre–industrial civilization came into existence gradually¸ during a period of major social and economic change. Everyone agrees¸ also¸ that linear explanations invoking irrigation, trade¸ or warfare are inadequate. Recent theories of the rise states invoke multiple¸ and often intricate¸ causes and are frequently based on systems models.
In the 1960´s¸Robert Adams¸ an expert on ancient Mesopotamia, introduced a new generation of complex theories when he argued that irrigation agriculture¸ increased warfare¸ and “local resource variability” were three factors vital in newly appearing urban civilizations. Each affected society and the other factors with positive feedback¸ helping to reinforce each other. The creation of food surpluses and the emergence of a stratified society were critical developments. Irrigation agriculture could feed a bigger population. Larger populations¸ an increase impermanent settlement¸ and trade with regular centers for redistributing goods were all pressures for greater production and increased surpluses actively fostered by dominant groups in society. The greatly enlarger surpluses enabled those who controlled them to employ larger numbers of artisans and other specialists who did not themselves grow crops.
Adams argued that some societies were better able to transform themselves into states because of the favorable variety of resources on which they could draw. Higher populations led to monopolies over strategic resources. These communities eventually were more powerful than their neighbors¸ expanding their territories by military campaigns and efficiently exploiting their advantages over other peoples. Such cities became early centers of major religious activities¸ of technological and artistic innovations¸ and of writing. Literacy¸ a skill confined to a few people¸ became an important source of power.
Archaeologists like Kent Flannery¸ who works in Mesopotamia¸ now saw the state as a very complicated “living” system, the complexity of which could be measured by the internal differentiation and intricacy of its subsystems¸ such as those for agriculture¸ technology, or religious beliefs. The way these subsystems were linked¸ and the controls that society imposed on the system¸ were vital. This model seemed to work well with Mesoamerican states¸ where pervasive religious beliefs formed close links between public architecture¸ the economy¸ and other subsystems of civilizations.
The management of a state is a far more elaborate and central undertaking than that of a small chiefdom. Indeed¸ the most striking difference between states and less–complicated societies is the degree of complexity in civilizations´ ways of reaching decisions and in their hierarchic organizations¸ not necessarily in their subsistence activities. Systems models of early states are bound to be complex¸ for they have to distinguish between mechanisms and processes of cultural change¸ and the socio–environmental pressures by which we have sought to explain in the regulations of environmental and economic variables in early civilizations¸ and indeed in any human society.
Environmental Change
Ecologically based theories, which also rely heavily on systems approaches, have enjoyed a relatively long life compared with many other hypotheses. For example¸ in a classic study of the Valley of Mexico¸ William Sanders and a group of archaeologists showed how the Aztec state created and organized huge agricultural systems that spread over the shallow waters of the lakes that once filled the valley. The variability of the local environment meant that the Aztecs had to exploit every environmental opportunity afforded them. Thus¸ Sanders argues the state organized large–scale agriculture to support a population of up to 250¸000 in and close to the Aztec capital¸ Tenochtitlán. Environmental factors were decisive in each area where civilizations began, he believes. Another important factor was centralized leadership.
The ecological approach has serious problems. How, for example, does one tell which environments would foster state formations? Fertile food plains like those in Mesopotamia and Egypt. Coastal rivers valleys like those in Peru? Highland plateaus like those of Mesoamerica. Or areas where land is in short supply (also coastal Peru)? States have arisen in regions where there are few geographic constraints, like Maya lowlands of Mesoamerica. Further¸ pre–industrial civilization developed without any sign of rapid population growth¸ in Iran (Persia) and other parts of southwest Asia. However¸ there can be no doubt those environmental factors were major factors in a very complex process of cultural change and response.
Science
Warfare
In the 1970s¸ anthropologists Robert Carneio used the archaeology of coastal valleys in Peru to argue that warfare played a key role in state formations. His “coercive theory” of state origins argued that the amount of agricultural land in these valleys was limited and surrounded by desert. So a series of predictable events led to the development of states. At first¸ autonomous farming villages flourished in the valley landscapes. However¸ as the population grew and more land was taken up, the communities started fighting over land and raided each other´s fields as they competed for limited acreage. Some of the village leaders emerged as successful warlords¸ became chieftains¸ and presided over large tribal polities. The valley population continued to grow¸ and warfare intensified until the entire region fell under the sway of a single¸ successful warrior¸ who presided over a single state centered on the valley. Then this ambitious ruler and his successors start raiding neighboring valleys. Eventually a multi–valley state developed¸ creating a much larger civilization.
Carneio´s theory is hard to test in the field¸ but an attempt to do so in Peru´s Santa valley showed no sign of autonomous villages. Rather¸ it depicted a much more complex¸ evolving settlement pattern over many centuries. Archaeologist David Wilson points out that the only “coercive” process came about around 400 A.C.E.¸ when the Moche people carved out a multi–valley state by military conquest of neighboring valleys. The conquest took place long after complex irrigation–based societies flourished in the Santa valley. As with irrigation hypotheses¸ reality is more complex than the straightforward Carnerio.
Warfare also can be rejected as a primary cause of civilization on other grounds. In earlier times¸ the diffuse social organizations of village communities had not yet led to the institutional warfare that resulted from the concentration of wealth and power in a few hands. There was raiding and violent conflict between kingdoms almost everywhere before state formations¸ which may have had a profound effect on peoples´ lives, but other powerful factors were simultaneously at play. Only when absolute and despotic monarchs came into power did warfare become endemic¸ with standing armies to control important resources¸ solve political questions¸ and ensure social inequality. This type of warfare presupposes authority and is a consequence of civilization.
Cultural Systems and Civilization
Most archaeologists agree that urban life and pre–industrial civilization came into existence gradually¸ during a period of major social and economic change. Everyone agrees¸ also¸ that linear explanations invoking irrigation, trade¸ or warfare are inadequate. Recent theories of the rise states invoke multiple¸ and often intricate¸ causes and are frequently based on systems models.
In the 1960´s¸Robert Adams¸ an expert on ancient Mesopotamia, introduced a new generation of complex theories when he argued that irrigation agriculture¸ increased warfare¸ and “local resource variability” were three factors vital in newly appearing urban civilizations. Each affected society and the other factors with positive feedback¸ helping to reinforce each other. The creation of food surpluses and the emergence of a stratified society were critical developments. Irrigation agriculture could feed a bigger population. Larger populations¸ an increase impermanent settlement¸ and trade with regular centers for redistributing goods were all pressures for greater production and increased surpluses actively fostered by dominant groups in society. The greatly enlarger surpluses enabled those who controlled them to employ larger numbers of artisans and other specialists who did not themselves grow crops.
Adams argued that some societies were better able to transform themselves into states because of the favorable variety of resources on which they could draw. Higher populations led to monopolies over strategic resources. These communities eventually were more powerful than their neighbors¸ expanding their territories by military campaigns and efficiently exploiting their advantages over other peoples. Such cities became early centers of major religious activities¸ of technological and artistic innovations¸ and of writing. Literacy¸ a skill confined to a few people¸ became an important source of power.
Archaeologists like Kent Flannery¸ who works in Mesopotamia¸ now saw the state as a very complicated “living” system, the complexity of which could be measured by the internal differentiation and intricacy of its subsystems¸ such as those for agriculture¸ technology, or religious beliefs. The way these subsystems were linked¸ and the controls that society imposed on the system¸ were vital. This model seemed to work well with Mesoamerican states¸ where pervasive religious beliefs formed close links between public architecture¸ the economy¸ and other subsystems of civilizations.
The management of a state is a far more elaborate and central undertaking than that of a small chiefdom. Indeed¸ the most striking difference between states and less–complicated societies is the degree of complexity in civilizations´ ways of reaching decisions and in their hierarchic organizations¸ not necessarily in their subsistence activities. Systems models of early states are bound to be complex¸ for they have to distinguish between mechanisms and processes of cultural change¸ and the socio–environmental pressures by which we have sought to explain in the regulations of environmental and economic variables in early civilizations¸ and indeed in any human society.
Environmental Change
Ecologically based theories, which also rely heavily on systems approaches, have enjoyed a relatively long life compared with many other hypotheses. For example¸ in a classic study of the Valley of Mexico¸ William Sanders and a group of archaeologists showed how the Aztec state created and organized huge agricultural systems that spread over the shallow waters of the lakes that once filled the valley. The variability of the local environment meant that the Aztecs had to exploit every environmental opportunity afforded them. Thus¸ Sanders argues the state organized large–scale agriculture to support a population of up to 250¸000 in and close to the Aztec capital¸ Tenochtitlán. Environmental factors were decisive in each area where civilizations began, he believes. Another important factor was centralized leadership.
The ecological approach has serious problems. How, for example, does one tell which environments would foster state formations? Fertile food plains like those in Mesopotamia and Egypt. Coastal rivers valleys like those in Peru? Highland plateaus like those of Mesoamerica. Or areas where land is in short supply (also coastal Peru)? States have arisen in regions where there are few geographic constraints, like Maya lowlands of Mesoamerica. Further¸ pre–industrial civilization developed without any sign of rapid population growth¸ in Iran (Persia) and other parts of southwest Asia. However¸ there can be no doubt those environmental factors were major factors in a very complex process of cultural change and response.
Environmental Change
Ecologically based theories, which also rely heavily on systems approaches, have enjoyed a relatively long life compared with many other hypotheses. For example¸ in a classic study of the Valley of Mexico¸ William Sanders and a group of archaeologists showed how the Aztec state created and organized huge agricultural systems that spread over the shallow waters of the lakes that once filled the valley. The variability of the local environment meant that the Aztecs had to exploit every environmental opportunity afforded them. Thus¸ Sanders argues the state organized large–scale agriculture to support a population of up to 250¸000 in and close to the Aztec capital¸ Tenochtitlán. Environmental factors were decisive in each area where civilizations began, he believes. Another important factor was centralized leadership.
The ecological approach has serious problems. How, for example, does one tell which environments would foster state formations? Fertile food plains like those in Mesopotamia and Egypt. Coastal rivers valleys like those in Peru? Highland plateaus like those of Mesoamerica. Or areas where land is in short supply (also coastal Peru)? States have arisen in regions where there are few geographic constraints, like Maya lowlands of Mesoamerica. Further¸ pre–industrial civilization developed without any sign of rapid population growth¸ in Iran (Persia) and other parts of southwest Asia. However¸ there can be no doubt those environmental factors were major factors in a very complex process of cultural change and response.