The idea that all of nature is governed by yin/yang and the Five Elements (Figure 2.1) lies at the heart of Chinese medicine. Zhu Yen (some time between −350 and −270) wrote extensively on the subject and the Five Elements are mentioned in both the Book of History and the Book of Rites (the dates for these are uncertain). The Ling Shu states that: ‘Nothing on earth or within the universe is unrelated to the Five Elements and Man is no exception’ (Ling Shu Chapter 64; quoted in Liu, 1988, p. 48).

The Five Elements, which are Wood, Fire, Earth, Metal and Water, represent the fundamental qualities of all matter in the universe. The Chinese term for Element is xing. Xing means to walk or to move, and therefore the word ‘Element’ is somewhat misleading because it implies something more akin to a basic constituent of matter. For this reason, the translation ‘The Five Phases’ is often used. However, because the term ‘Element’ is so established, we continue to use it here, but the reader should be clear that an Element is a process, movement or quality of qi, not a fixed ‘building block’ (Rochat, 2009, p. 13; Kaptchuk, 2000, p. 437; Maciocia, 1989, p. 15; Needham, 1956, p. 244).

Each Element has its own particular quality of qi: ‘As soon as the Five Elements are formed, they have each their specific nature’ (Chou Tun-I; quoted in Needham, 1956, p. 461). One of the earliest texts describing the Five Elements outlined this emphasis on the different qualities of the Elements.

Above all, the Five Elements serve as a model for understanding the inexorable succession of the seasons. For many Daoists and Naturalists virtually no distinction was made between the nature of the seasons, the climate resonant with each season and the cyclical changes taking place in the human, animal and vegetable worlds. In plants the never-ending cycle of growth, flowering, harvest, decline and storing informed them of the differing qualities of each season. The behaviour of animals and humans in each season was also seen to be governed by the same laws.

Over the course of history there have been several different models of Five Element theory, some coming from its application to agriculture or politics (see, for example, Cheng, 1987, pp. 18–22; Maciocia, 1989, pp. 15–35; Matsumoto and Birch, 1983, pp. 1–8). Five Element Constitutional Acupuncture is based on the model of the Five Elements set out in the Nei Jing and Nan Jing. This model, which envisages the Five Elements in a cyclical creative cycle, has always been the dominant one used by acupuncture practitioners.

Chinese medicine, like any system of medicine, is predominantly concerned with understanding and alleviating physical and psychological suffering. The writers of the medical classics strove to understand how the Five Elements affected people and how physicians could observe this. The ‘resonances’ associated with each Element are how the condition of the Elements inside the person is revealed to the practitioner. ‘Associations’ or ‘correspondences’ are the usual words used in this context, but these words imply a relationship between separate entities. We have chosen to use the word ‘resonances’ as it implies an underlying sameness.

When people’s qi becomes either deficient (xu) or full (shi) within an Element, changes start to take place in various aspects of the physical body as well as in the mind and spirit. (This idea is present in both the Nei Jing and the Nan Jing, but is put most succinctly in Nan Jing, Chapter 16.)

The practitioner diagnoses the dysfunction by perceiving disharmony in patients’ odour, voice tone, facial colour and in the external expression of their inner state. It is not that the imbalanced qi ‘causes’ the changes to happen, but that the odour, colour, tone and emotion ‘resonate’ (ying) in harmony with the condition of the qi of the Element (see Birch and Felt, 1998, p. 93, for a description of how ‘resonance’ is a more understandable concept to the Chinese than to Westerners).

The Ling Shu states: ‘Between Heaven and Earth, the number five is indispensable. Man also resonates with it’ (Yang and Chace, 1994, p. 54). This concept of ‘resonance’, exemplified by sympathetic vibrations in gongs across a temple hall, was vital to early Chinese ideas concerning science and medicine (Needham, 1956, pp. 282–283). Indeed, ‘The fundamental idea of the Book of Changes (I Jing) can be expressed in one word – resonance’ (Shih Shuo Hsu Yu; quoted in Needham, 1956, p. 304).

The quality of qi resonant with the Wood Element in Heaven manifests as the season of spring, the climatic qi of wind and in a person as the emotion of anger. Humanity stands between Heaven and Earth and the Five Elements are present within us just as they are present throughout all the manifestations of the Dao.

There have been many resonances attributed to the Elements over the centuries, many not in a medical context. Table 2.1 sets out the resonances commonly used by practitioners of Five Element Constitutional Acupuncture (these resonances are often referred to in the classics, but Nan JingChapter 34 is devoted to this topic). They are the resonances that most clearly give us an understanding of how the Five Elements manifest in people. It is easy to say that the Wood Element plays the same role in people’s character as the spring plays in the annual cycle of the seasons. It requires considerable experience and depth of understanding, however, to be able to make an accurate diagnosis based on observation of how these resonances manifest in people. For example, when the Water Element is out of balance then a putrid odour, an imbalance in the person’s ability to deal effectively with fear, a groan in the voice tone and a blue facial colour also arise. Cultivating the ability to diagnose from such signs is one of the main challenges for the Five Element Constitutional Acupuncturist.

Human emotions in particular are seen as being equivalent to the different forms of qi present throughout Nature. Often they are the most overt manifestations of the Element that can be discerned in the person.