Thus, we can understand that everything requires for its existence a reciprocal relationship between the dual characteristics of yang and yin. However, there is another pair of dual characteristics in reciprocal relationship which are even more fundamental to existence than the dual characteristics of yang and yin.
Every entity possesses both an outer form and an inner quality. The visible outer form resembles the invisible inner quality. The inner quality, though invisible, possesses a certain structure which is manifested visibly in the particular outer form. The inner quality is called internal nature, and the outer form or shape is called external form.
Since internal nature and external form refer to corresponding inner and outer aspects of the same entity, the external form may also be understood as a second internal nature. Therefore, the internal nature and external form together constitute dual characteristics.
Let us take human beings as an example. A human being is composed of an outer form, the body, and an inner quality, the mind. The body is a visible reflection of the invisible mind. Because the mind possesses a certain structure, the body which reflects it also takes on a particular appearance. This is the idea behind a person’s character and destiny being perceived through examining his outward appearance by such methods as physiognomy or palm reading.
Here, mind is the internal nature and body is the external form. Mind and body are two correlative aspects of a human being; hence, the body may be understood as a second mind. Together, they constitute the dual characteristics of a human being. Similarly, all beings exist through the reciprocal relationships between their dual characteristics of internal nature and external form. |