Just as the opening of the chapter "The Chinese Tradition" states, there is no work that could ever completely cover the abundance of Chinese history. The earliest inhabitants of China tended to migrate southward along fertile areas near the river. The Han set themselves apart from others with their ingenious agricultural ways that were needed for wet rice cultivation and silk production. They also were very interested in history and chronology and were able to develop written language early in their history. The Hundred Schools era was a time from about 500 to 300 B.C. when there was much debate between the schools of thought. For example, while Mohism practiced universal love, Confucianism was associated with the idea of graded love, which means someone is expected to care more about those that are closer within the family, and less for those farther. Other popular philosophies included the Daoists, Legalists, Logicians, yin-yang, and feng-shui. Buddhism originated in India and since it came to China in the 2nd century it is not classified as part of the Hundred Schools. For the most part, Confucianism was considered the state philosophy, but it was influenced by the other schools. Of great notability was the governmental structure, which included supreme emperor at the top and the court structure, which consisted of the empress and her family. After the 14th century, a significant aspect of the imperial bureaucracy was the Six Boards: Board of Personnel, Board of Revenue, Board of Rites, Board of War, Board of Punishment, and Board of Works. The structure of local government was also intricate, with provinces divided into prefectures, subsequently divided into counties, townships, and villages. The county magistrate had to govern a vast area with scarce resources to do so, yet all local power was subject to that of higher levels of government. The competitive civil service examination was used to select prestigious Chinese officials and was based on Confucian classics.