The Tang Dynasty contributed important ideas to the world that have endured. The notion that government officials should be selected based on ability and educational merit was adopted in China during the Tang dynasty. The idea of a civil service exam system allowed China to have a firm foundation of government. The selection of people for the government was based on the principles of Confucianism. The Tang made tremendous advancements in health and science that led to the understanding of diabetes. Their experimentation with urine allowed them to realize that diabetes was related to sugar. The Chinese invented gunpowder during this period as well. The Tang Dynasty was a period of innovation and creativity. Wood block printing and clock making were important inventions that enhanced the lives of their citizens. The period was also marked by increased commerce and trade with the civilizations to the west. The Tang demonstrated that through a skilled bureaucracy, strong military, and interest in science and the arts, a civilization can be prosperous and peaceful.