The most popular and most fundamental truths, principles, and methodologies tend to be expressed in simple words and are easy to understand. Dadao (大道) means great truth, or universally applicable laws governing nature and society, or the fundamental principles for people to follow in treating nature and governing society. The Chinese character jian (简) means simple, concise, and easy. The term is often used to describe the governance of a state and management of society. It has two primary meanings. First, it means that the most popular and fundamental truths should be expressed in simple words so that ordinary people can easily understand and put them into practice. Second, dadao is not something separate and far away from reality. Rather, it is a practical ethical principle which is easy for people to follow in their daily lives. As long as one sees through the seemingly complicated superficialities and traces the source of things, one will be able to grasp the fundamental truths, discover the basic rules, and comprehend them in spite of the complexity.

He is able to keep himself to the right path if he has an excellent command of extensive literary knowledge, constrains himself with ritual propriety, and starts from the most obvious point to arrive at the most convenient situation. (Zhang Zai: Enlightenment Through Confucian Teachings)

All great truths are most plain and easy to understand and most common in people’s everyday life... as such, people do not think them as truths. (Yang Jian: Cihu’s Commentary on The Book of Songs)

The Book of Changes is boundless and limitless, through the ever changing nature it offers. The reason why The Book of Changes offers infinite changes is attributable to the two kinds of qi: yin and yang. The reason why everything can be traced to the two kinds of qi, yin and yang, is that the theory of yin and yang is easy to understand and implement. (Xiang Anshi: Expounding the Theories of The Book of Changes)