The ages of human history

As a custom, historians divide eras of people according to the material from which they made their tools. The earliest tools were made of stone, and so we have the Stone Age. Then follow the Bronze Age and the Iron Age. More recently, a finer alloy of iron allowed greater expansion of industry, so we can refer to a Steel Age. Then, around the middle of the twentieth century, we entered the Plastic Age.

Here is a trick question: when does one age end and another begin? The question cannot be answered until we specify the area in question and even which group within that area. The Bible describes a time, when Saul was king of Israel, that the Israelites were in the Bronze Age while the Philistines were in the Iron Age. This gave the Philistines advantages over the Israelites—military advantages and agricultural advantages—because the Philistines were using better tools.

Each of these ages is further divided into various segments, often very detailed in their descriptions. Pottery, basket weaving, and other early industries help to define these segments; they also indicate when two or more groups of people exchanged items they had made. The larger ages are sufficient for a general discussion of history, although the Stone Age is generally divided. When I was younger, we learned about the Paleolithic Age, or Old Stone Age; and the Mesolithic, or Middle Stone Age, and the Neolithic, or New Stone Age. I never learned all the distinctions among the three stone ages, aside from the fact that the Paleolithic came first and the Neolithic is most recent. Now books only separate the Paleolithic and Neolithic ages. The distinction is easy: Paleolithic people have no set home; they travel to hunt and harvest their food. Neolithic people have settlements; they raise flocks and herds of animals, and they plant seeds and tend the plants that grow and harvest the crops when they are ripe.

Extremely useful tools are made from stones. Flint and obsidian are especially helpful because sharp blades can be chipped from these stones. Sharp stones became knives that cut food, axes that cut wood, and weapons that helped when hunting animals or when battling other groups of people for resources. Many North Americans have gathered what are commonly called “arrowheads.” Most of these shaped stones are too large for arrows; they were used instead on short spears that were thrown at a target, such as deer or bison. Professional historians and archaeologists classify these tools as “projectile points.”

Back to the trick question: speaking on a world-wide basis, the Paleolithic Age has never ended. Some people today still choose to live in a Paleolithic pattern. Not only are their tools made of stone; they travel to hunt and to harvest their food. They have no permanent settlements. They are aware of newer possibilities in civilization—bronze and iron and steel and plastic. They choose to perpetuate the ways of their ancestors. Australia, Siberia, and many other parts of the world are home to Paleolithic groups that preserve their ancient customs and choose not to adapt to newer ways.

No written records describe the discovery of bronze. Bronze is an alloy, a mixture of copper and tin. (Some parts of the world had a Copper Age before they entered the Bronze Age.) Copper and tin ores exist naturally in some rocks; historians assume that people who gathered rocks to line their fire pits found a new substance in the morning when the fires had gone out. This new substance, bronze, could be shaped more easily than stone. Bronze blades on weapons and other tools lasted longer than stone blades. The advantage of bronze tools made them the choice of most civilized groups that encountered them, either by their own discovery or through trade with other groups.  

Iron is even more durable than bronze. Iron does not melt in a normal fire, which is why many campers use cast iron pots and skillets. Pure iron is a powder, but a mixture of iron and carbon produces an alloy which is extremely useful. Once people learned how to blow air into a fire to make it hotter, they were ready for the Iron Age. The earliest appearance of that industry seems to have occurred among the Hittites, living in what now is the country called Turkey. The technology spread to neighboring civilizations. It appears to have arisen spontaneously in China and in central Africa as well. Iron technology caused a great gap between “haves” and “have-nots” in the ancient world. Some civilizations, including the Philistines, attempted to preserve a monopoly on iron technology, but they were only able to hold that monopoly for a few years, never for long.

About a thousand years ago, chemists in China found a new way of combining iron and carbon which made a finer version of iron, which we call steel rather than cast iron. Once again, this new technology offered advantages over the older iron tools. Gradually, this chemical knowledge moved along the trade routes called the Silk Roads, until it reached the British Isles in western Europe. The British had advantages which had not existed in China or in other civilizations on the Silk Roads: they had iron deposits, coal deposits, and running water for generating power all located near one another. Chinese inventors made the first water wheels—wheels turned by a flowing stream of water, generating power to operate machinery such as grain mills. Europeans improved this Chinese invention by positioning the water wheels vertically instead of horizontally in the streams of water. This allowed gravity to add to the energy of the moving water, generating even more power. The Industrial Revolution began in Great Britain a few centuries ago because of the use of these Chinese discoveries—the recipe for finer steel, and the power that comes from a wheel turned by water.

Now most of the tools we use are made, at least in part, from plastic. Plastic is made from petroleum, so people will need to continue mining and refining petroleum even if it ceases to be a source of energy to operate vehicles and to generate electricity. Plastic is extremely useful for tools, but plastic can cause more damage to the environment than stones or metal, since it does not exist as such in nature. People have shown in the past that we can be inventive, finding new materials to improve older technologies. Perhaps even now researchers in a laboratory somewhere are experimenting with a new substance that will replace plastic and move humanity into yet another age. J.

Stepping back to see the big picture (socialism, continued)

The idea of socialism arose as a response to the Industrial Revolution and to some of the problems within that Revolution. In turn, the Industrial Revolution was a consequence of several large historical movements that came together in a particular time and place to shape human history.

When historians seek to understand and explain an event or a movement, they must take a step back and look at the broader picture. Often this requires further steps back, sometimes to view the entire panorama of history. Analyzing the causes of the Industrial Revolution includes such steps and such a view.

The Persian Empire, Mauryan Empire, Han Empire, and Roman Empire each constructed roads to facilitate government communication across their stretches of land and to accommodate the travel of armies. As a result of those roads (and associated waterways), merchants and merchandise began to flow through and beyond these empires. Imperial governments favored the exchange of merchandise, since it could be taxed every time it changed hands. Two thousand years ago, Italian glass could be bought in China, and Chinese silk could be bought in Italy. Anything that could be moved, bought, and sold traveled along these roads and waterways: fabrics, spices, precious metals and gems, artwork, food, livestock, and slaves. Over the centuries, travel and trade ebbed and flowed because of other political and economic conditions. Along the same routes traveled ideas—religious ideas, political and economic ideas, and technology—and disease also spread from culture to culture along the same roads.

Genghis Khan’s Mongolian Empire sparked additional travel and trade along these routes. Asian produce and technology traveled into Europe. Bubonic plague (the Black Death) began somewhere in inland China but spread to the cities of China and to Mediterranean cities, and from there to all the populated areas of Europe. This disease had a devastating consequence upon commerce and economic activity, both because of the high death rate of the disease and because of the fear of disease that spread throughout the population.

Disruption of trade, caused by disease and by political developments in the eastern Mediterranean, caused western European governments to seek a shortcut to African and Asian goods, eliminating some of the middlemen. Using Asian technology, including the Chinese compass and the Arabian astrolabe, Portuguese mariners set sail down the coast of Africa and into the western ocean. Spain, England, and the Netherlands eventually followed. Early results of the Portuguese expeditions included expansion of the sugar industry and development of the African slave trade. But Columbus’ abortive attempts to cross the ocean between Spain and east Asia revealed an expanse of islands and continents in the western hemisphere. Soon commerce between the Old World and the New World brought new foods to Europe; those new foods helped to support a growing population, recovering from the plague.

As the population grew, though, landowners found that they could enclose their land for more specific use, such as the grazing of sheep to produce wool. This removed peasants from the land and from their agricultural activities, sending them into the towns and cities. The growing urban population disrupted the guilds and other work that the tradespeople had developed over centuries. More new technology met this change in population dispersion to ignite the Industrial Revolution in England.

A Chinese inventor had learned how to harness the power of a flowing river with a wheel, channeling that energy to other uses. Europeans improved the water wheel by installing it vertically instead of horizontally, effectively letting the power of gravity increase the power generated by the moving water of the river. Later, the same idea was converted to generation of power from steam, which no longer needed the immediate presence of a river.

Around the same time, a Chinese chemist found a new recipe for steel. Iron technology had begun in Anatolia (the location of modern Turkey) about three thousand years ago. Pure iron is a powder, but iron combined with carbon makes cast iron, which produced tools stronger and more durable than the stone and bronze tools used previously. (Ironworking was discovered independently in central Africa around the same time.) About a thousand years ago, a new recipe for iron and carbon produced steel, a great improvement over cast iron. The new recipe used coal instead of burnt wood as a carbon source. Coal and iron deposits both exist in China, but not near each other. In England, iron and coal and running water are found in close proximity. Deforestation of England also provided greater interest in coal, both as fuel and as an ingredient for making steel. The Industrial Revolution was ready to emerge.

As the urban population grew, new businesses began to exploit the work force to get around the guild economy of Europe. Shepherds and shearers would sell the raw wool from their sheep to moneyed peasants. These peasants would then hire some families to card the wool in their homes. The carded wool was then returned to the business owners, who hired other people to spin the wool into thread. The spinners returned the thread, which the business owners then sent to weavers, who used looms to change the thread into cloth. The cloth was chemically treated by fullers, and the improved cloth was sent to tailors, who cut the cloth into pieces and sewed it into garments. Shepherds, Shearers, Carders, Spinners, Weavers, Fullers, and Tailors were each paid for their labor, and afterward they all bought clothing from the businesses that had paid them for their work. Today many family names reflect the role of their ancestors in this industry.

Steel tools and steam power made factories possible. No longer did the work have to be sent into homes and brought back to the businesses: the businesses could own the buildings and machines where the work was done. These machines could produce far more clothing from far fewer laborers. The Industrial Revolution began in England, spread into other European countries and then to North America, and eventually filled the world. The impact of this revolution changed the lives of many people, from wealthy business owners to impoverished workers. J.