Another important change can be seen from this time on. Under the feudal system of the Chou strict primogeniture among the nobility existed: the fief went to the oldest son by the main wife. The younger sons were given independent pieces of land with its inhabitants as new, secondary fiefs. With the increase in population there was no more such land that could be set up as a new fief. From now on, primogeniture was retained in the field of ritual and religion down to the present time: only the oldest son of the main wife represents the family in the ancestor worship ceremonies; only the oldest son of the emperor could become his successor. But the landed property from now on was equally divided among all sons. Occasionally the oldest son was given some extra land to enable him to pay the expenses for the family ancestral worship. Mobile property, on the other side, was not so strictly regulated and often the oldest son was given preferential treatment in the inheritance.

The technique of cultivation underwent some significant changes. The animal-drawn plough seems to have been invented during this period, and from now on, some metal agricultural implements like iron sickles and iron plough-shares became more common. A fallow system was introduced so that cultivation became more intensive. Manuring of fields was already known in Shang time. It seems that the consumption of meat decreased from this period on: less mutton and beef were eaten. Pig and dog became the main sources of meat, and higher consumption of beans made up for the loss of proteins. All this indicates a strong population increase. We have no statistics for this period, but by 400 B.C. it is conceivable that the population under the control of the various individual states comprised something around twenty-five millions. The eastern plains emerge more and more as centres of production.

The increased use of metal and the invention of coins greatly stimulated trade. Iron which now became quite common, was produced mainly in Shansi, other metals in South China. But what were the traders to do with their profits? Even later in China, and almost down to recent times, it was never possible to hoard large quantities of money. Normally the money was of copper, and a considerable capital in the form of copper coin took up a good deal of room and was not easy to conceal. If anyone had much money, everyone in his village knew it. No one dared to hoard to any extent for fear of attracting bandits and creating lasting insecurity. On the other hand the merchants wanted to attain the standard of living which the nobles, the landowners, used to have. Thus they began to invest their money in land. This was all the easier for them since it often happened that one of the lesser nobles or a peasant fell deeply into debt to a merchant and found himself compelled to give up his land in payment of the debt.

Soon the merchants took over another function. So long as there had been many small feudal states, and the feudal lords had created lesser lords with small fiefs, it had been a simple matter for the taxes to be collected, in the form of grain, from the peasants through the agents of the lesser lords. Now that there were only a few great states in existence, the old system was no longer effectual. This gave the merchants their opportunity. The rulers of the various states entrusted the merchants with the collection of taxes, and this had great advantages for the ruler: he could obtain part of the taxes at once, as the merchant usually had grain in stock, or was himself a landowner and could make advances at any time. Through having to pay the taxes to the merchant, the village population became dependent on him. Thus the merchants developed into the first administrative officials in the provinces.

In connection with the growth of business, the cities kept on growing. It is estimated that at the beginning of the third century, the city of Lin-chin, near the present Chi-nan in Shantung, had a population of 210,000 persons. Each of its walls had a length of 4,000 metres; thus, it was even somewhat larger than the famous city of Loyang, capital of China during the Later Han dynasty, in the second century A.D. Several other cities of this period have been recently excavated and must have had populations far above 10,000 persons. There were two types of cities: the rectangular, planned city of the Chou conquerors, a seat of administration; and the irregularly shaped city which grew out of a market place and became only later an administrative centre. We do not know much about the organization and administration of these cities, but they seem to have had considerable independence because some of them issued their own city coins.

When these cities grew, the food produced in the neighbourhood of the towns no longer sufficed for their inhabitants. This led to the building of roads, which also facilitated the transport of supplies for great armies. These roads mainly radiated from the centre of consumption into the surrounding country, and they were less in use for communication between one administrative centre and another. For long journeys the rivers were of more importance, since transport by wagon was always expensive owing to the shortage of draught animals. Thus we see in this period the first important construction of canals and a development of communications. With the canal construction was connected the construction of irrigation and drainage systems, which further promoted agricultural production. The cities were places in which often great luxury developed; music, dance, and other refinements were cultivated; but the cities also seem to have harboured considerable industries. Expensive and technically superior silks were woven; painters decorated the walls of temples and palaces; blacksmiths and bronze-smiths produced beautiful vessels and implements. It seems certain that the art of casting iron and the beginnings of the production of steel were already known at this time. The life of the commoners in these cities was regulated by laws; the first codes are mentioned in 536 B.C. By the end of the fourth century B.C. a large body of criminal law existed, supposedly collected by Li K'uei, which became the foundation of all later Chinese law. It seems that in this period the states of China moved quickly towards a money economy, and an observer to whom the later Chinese history was not known could have predicted the eventual development of a capitalistic society out of the apparent tendencies.

So far nothing has been said in these chapters about China's foreign policy. Since the central ruling house was completely powerless, and the feudal lords were virtually independent rulers, little can be said, of course, about any "Chinese" foreign policy. There is less than ever to be said about it for this period of the "Contending States". Chinese merchants penetrated southward, and soon settlers moved in increasing numbers into the plains of the south-east. In the north, there were continual struggles with Turkish and Mongol tribes, and about 300 B.C. the name of the Hsiung-nu (who are often described as "The Huns of the Far East") makes its first appearance. It is known that these northern peoples had mastered the technique of horseback warfare and were far ahead of the Chinese, although the Chinese imitated their methods. The peasants of China, as they penetrated farther and farther north, had to be protected by their rulers against the northern peoples, and since the rulers needed their armed forces for their struggles within China, a beginning was made with the building of frontier walls, to prevent sudden raids of the northern peoples against the peasant settlements. Thus came into existence the early forms of the "Great Wall of China". This provided for the first time a visible frontier between Chinese and non-Chinese. Along this frontier, just as by the walls of towns, great markets were held at which Chinese peasants bartered their produce to non-Chinese nomads. Both partners in this trade became accustomed to it and drew very substantial profits from it. We even know the names of several great horse-dealers who bought horses from the nomads and sold them within China.

3 Cultural changes

Together with the economic and social changes in this period, there came cultural changes. New ideas sprang up in exuberance, as would seem entirely natural, because in times of change and crisis men always come forward to offer solutions for pressing problems. We shall refer here only briefly to the principal philosophers of the period.

Mencius (c. 372-289 B.C.) and Hsün Tz[)u] (c. 298-238 B.C.) were both followers of Confucianism. Both belonged to the so-called "scholars", and both lived in the present Shantung, that is to say, in eastern China. Both elaborated the ideas of Confucius, but neither of them achieved personal success. Mencius (Meng Tz[)u]) recognized that the removal of the ruling house of the Chou no longer presented any difficulty. The difficult question for him was when a change of ruler would be justified. And how could it be ascertained whom Heaven had destined as successor if the existing dynasty was brought down? Mencius replied that the voice of the "people", that is to say of the upper class and its following, would declare the right man, and that this man would then be Heaven's nominee. This theory persisted throughout the history of China. Hsün Tz[)u]'s chief importance lies in the fact that he recognized that the "laws" of nature are unchanging but that man's fate is determined not by nature alone but, in addition, by his own activities. Man's nature is basically bad, but by working on himself within the framework of society, he can change his nature and can develop. Thus, Hsün Tz[)u]'s philosophy contains a dynamic element, fit for a dynamic period of history.