After sitting upright on a chair, what would Cheng Yi do next to continue his practice of quiet-sitting meditation? Because there are many methods of beholding the vivacity of the myriad things, as discussed earlier, Cheng Yi seemed to have choices to answer this question. However, given the prevalence of contemplative breathing as a method to deepen meditation across various traditions, it is worth asking whether Cheng Yi used this method as well. The following three passages provide evidence that Cheng Yi did ascribe a certain significance to meditative breathing:

The genuine origin (真元) is where vital-energy is born and does not mix with external vital-energy (外氣), although it can be nourished (涵養) by it. This is similar to how fish live in water; their life is not created by the water but rather nourished and sustained by it. Humans also live in the midst of the vital-energies of heaven and earth, no different from how fish live in water. The nourishment we receive from food and drink also comes from external vital-energy. Breathing involves the closing and opening [of the transformative mechanism of the universe]. The air that is exhaled is not the same as the air that is inhaled. It is the genuine origin that generates the air, and when the cosmic mechanism opens, external air enters accordingly. The creativity of the genuine origin does not require assistance from these external vital-energies.[61]

By examining one’s own body, all the pattern-principles of the universe can be discovered. The contraction and expansion [of the transformative mechanism of the universe] are evident in the intervals between breaths (鼻息之間). Contraction and expansion are merely derivatives of pattern-principle, and there is no need to turn exhaled, contracted air into inhaled, expanded air. The pattern-principle of constant creativity (生生之理) implies that contraction and expansion do not naturally cease.[62]

The phrase “One yin and one yang is called Dao”[63] refers to a pattern-principle that is deeply profound and cannot be fully expressed in words. Dao explains why there are yin and yang: whenever we speak of Qi (vital-energies), it always involves two forms. The opening and closing [of the transformative mechanism of the universe] already implies mutual affection (感). Whenever there are two forms of Qi, mutual affection follows. Dao explains why there is the opening and closing mechanism, and what is opening and closing is the yin and yang Qi. It is not accurate for Laozi to say that the vacuum can generate Qi. There is no priority between the interplay of the opening yang and the closing yin, and it is impossible to say that there is yin today and yang tomorrow. This is like a person’s shadow, which appears simultaneously with the person. It cannot be said that the person exists today and their shadow emerges tomorrow; they arise together.[64]

For Cheng Yi, the significance of meditative breathing consists in its role in absorbing external vital-energies to nourish, rather than generate, the genuine origin (真元) of human life. The genuine origin refers to the universal pattern-principle of constant creativity, or simply the Dao, which creates yin and yang vital-energies. The constant interplay of yin and yang comprises the generative and restorative mechanism of cosmic transformation, and this mechanism can be contemplated when one focuses on breathing.

While the term 真元was present in Daoist texts,[65] Cheng Yi rejected the idea of a temporal sequence between yin and yang vital-energies, thus challenging Laozi’s Daoist cosmology that posits a primeval stage of the vacuum (虚) or formless vital-energy (元氣) that eventually gives rise to concrete vital-energies.[66] Cheng Yi’s cosmology, rooted in the Ruist commentarial tradition of the Classic of Change, has a distinct ontological orientation: the Dao, or supreme pattern-principle, which nontemporally creates yin, yang, and other forms of vital-energies. Once created, the interplay of yin and yang persists without temporal beginning or end.

In this Ruist metaphysics, when contemplating one’s breath, the focus is not on the sequence of inhalation and exhalation. Instead, it is on the closing and opening of the transformative mechanism of the entire universe, which allows one to contemplate the supreme cosmic pattern-principle of constant creativity. While human life requires nourishment from breathed air, food, and drink, all these originate from the genuine origin of the entire universe. Meditative breathing serves as a reminder of the genuine origin of our life.