Harmony Between Yin and Yang
Yin and yang are two basic concepts of ancient Chinese philosophy. Their primary meanings came from the idea that "the sunny side is yang and the shady side is yin" in ancient times. The idea expressed the ancients' most intuitive understanding of those contrasting yet harmonious phenomena in nature such as the rotation between the sun and the moon, between day and night, between winter and summer, and between cloudy and sunny days, and the existence of two genders. Since the Warring States Period (475-221 BC), the meanings of yin and yang had been further extended, from being mere descriptions of natural phenomena to two highly abstract philosophical concepts in dichotomy. Yin and yang are thus not only concepts depicting the state of things in nature, but also basic concepts for describing social phenomena, becoming philosophical concepts regarding opposite phenomena in general. It can be said that the concepts of yin and yang constitute a basic way of thinking of the ancient Chinese and a basic framework for them to understand the world.
Harmony between yin and yang is the most optimal and ideal relationship between the two. The Chinese people often say that "yin or yang will not grow when they are isolated," indicating that it is their interaction that creates the entire world. According to the Chinese classic Lao Zi, "All things stand, facing yang and against yin. The interaction between yin and yang creates a state of harmony." It suggests that all things are generated from the interaction between yin and yang, and the balance or harmony between yin and yang is the most ideal state of this interaction. Therefore, the pursuit of harmony is actually pursuing the harmony between yin and yang.
阴阳和合
阴、阳，是中国古代哲学的基本范畴，其本意来自上古“向日为阳，背日为阴”观念，表达了上古先民对自然界天地百象、日月轮转、昼夜交接、寒暑更替、阴晴变换、男女雌雄等对立而和谐现象的直观体认。战国时期以来，阴阳概念得到进一步引申，从概括自然矛盾现象的概念高度抽象成一种二分法的哲学范畴。至此，阴阳不仅是表征自然万物状态的概念，也是描述社会现象的基本概念，成为泛指对立现象的一个哲学范畴。可以说，阴阳的观念代表着中国古人的一种基本思维方式和认识世界的基本框架。
阴阳和合，是对二者关系的最高揭示，也是对一种理想境界的塑造。中国人通言道“孤阴不生，孤阳不长”，意思是阴阳的共同作用造就了世界万物。《老子》提出“万物负阴而抱阳，冲气以为和”，认为万物由阴阳而来，其最理想状态就是阴阳之间的平衡、和谐。所以，对“和”的追求，实际上就是追求阴阳理想状态，即阴阳和合。
