Mr. Zongxuan's Theory of Profound Outlines: Chapter 12 - Yang Prevails Leads to Immortality

 When Yang and Yin combine, humans are born. The soul is the Yang spirit, and the魄 (po) is the Yin spirit. After conception, Qi circulates to nurture the body and form its shape. However, this state is not complete; if it were complete, each would return to its origin. Therefore, when Yin prevails, Yang is exhausted, leading to death; when Yang prevails, Yin is dissolved, leading to immortality. Softness, kindness, chastity, and purity belong to Yang. Rigidity, cruelty, jealousy of evil, licentiousness, and turbidity belong to Yin. When the mind is calm and empty, Yang harmony infiltrates the will; when it is restless and desirous, Yin Qi enters the clarity. The control of these two lies within ourselves. When Yang prevails and Yin is subdued, this is the gradual path to longevity. This gradual process is the beginning of ascending the Dao and the first step toward immortality.

 Explanation: Yin and Yang mix to produce humans. The soul is the Yang spirit, and the魄 (po) is the Yin spirit. After conception, Qi circulates throughout the body, forming the physical shape. However, this is not complete because if it were complete, it would return to the pre-heaven state. Thus, if Yin Qi is excessive, Yang will be exhausted leading to death; if Yang Qi is strong, Yin will be dissolved, resulting in immortality. The nature of Yang is soft, kind, chaste, and pure, while Yin is rigid, cruel, jealous of evil, licentious, and turbid. If the mind is indifferent, Yang harmony prevails; if one is anxious and indulges in desires, Yin Qi will have a destructive effect. The control of these two aspects lies within oneself. When Yang prevails and Yin is subdued, one can gradually achieve longevity. This is called the gradual path to longevity. Gradualness is the beginning of cultivating the Dao and the initial ladder to immortality.

 Analysis: The distinction here is that Mr. Zongxuan assigns the Yang spirit and Yin spirit to the soul and魄 (po) respectively. He defines the Qi of softness, kindness, and chastity as Yang, and the Qi of rigidity, cruelty, jealousy of evil, licentiousness, and turbidity as Yin. Through this distinction between Yin and Yang, he proposes that by making Yang prevail and Yin dissolve, one can achieve longevity. The reasoning is simple: softness, kindness, and chastity belong to the realm of life-generating Qi, while rigidity, cruelty, jealousy of evil, licentiousness, and turbidity belong to the realm of killing/dissipating Qi. The more life-generating Qi the human body absorbs, the stronger the vitality; the more killing/dissipating Qi is absorbed, the faster the consumption. Therefore, behind this Yin-Yang distinction lies a quantity of accumulation. This accumulation is referred to as the gradual path to longevity.