1 Dual cultivation of one’s self- nature and physical body, as mentioned in the last chapter, is the fundamental method of cultivation, as passed down in China from generation to generation for over 4,000 years.
2 While speaking about one’s nature and physical body, we must first understand that there is a distinction between “innate” and “acquired.”
3 From the time of their parents’ union, humans are endowed with a small amount of perfect qi, which has been given a physical frame. This perfect qi is innate and has no physical form or substance.
4 The sperm of the man unites with the ovum of the woman to form a fetus, which is the acquired body. It is physical and it is made of substance.
5 While in the mother’s womb, the perfect qi and the acquired body are originally united. As it is said, “without one’s own nature, life cannot exist; without life, one’s nature cannot become.”
6 After ten lunar months, the developed fetus has sufficient qi. As soon as the fetus leaves its mother’s womb, they separate. Thenceforth, one’s nature loses sight of the physical body, and physical body loses sight of one’s nature. This division persists from youth to middle age and continues through old age, until death.
7 Thus, ancient Daoists put great emphasis on one’s self-nature and physical body. They proposed dual cultivation of one’s self-nature and physical body. They proposed to return to the source, by tempering jing, qi, and shen, in order to remake the self-nature and the living body.
8 They also said: “To cultivate only the physical body but not one’s nature is a fatal flaw; to cultivate only one’s nature but not life sets the spirit adrift for a thousand eons, with no hope to enter the sacred.”
9 The life of a person in an acquired body can exist solely depends on the three treasures: jing, qi and shen.
10 Qi is refined out of jing, and when jing is full, qi will be replete. When qi is replete, shen becomes sufficient.
11 When shen and qi become sufficient, a person will become quick-thinking, acute of hearing, sharp in vision, and sound of limb.
12 The mating of male and female is the worldly Dao. The dual cultivation of one’s self-nature and physical body is the immortal Dao.
13 The worldly Dao follows nature’s course, which allows people to be born and thus there is life and death. The immortal Dao is the reversal of the worldly Dao. Cultivation that reverses the flow attains the Dao, so that existence would span a myriad eons.
14 Humans eat the five grains,  which are converted to yin jing [essence]. Un-tempered jing accumulates and creates disturbance in the body. Thus sexual desires arise and create havoc for the mind and spirit.
15 It is said that when a person is warm and fed, lustful thoughts will arise. Because life energy is limited, indulgence without restraint is sure to cause an early death.
16 Ancient Chinese Daoists had a great wish to temper spirit and flesh, to go beyond restraints of the physical world, in order to gain life without death. This is why Daoist cultivation begins with “purifying the heart and reducing desires.”
17 All in all, the inner refining of jing, qi and shen, which is realized through a gradual learning process, is normally divided into three stages based on practical experiments: refining jing into qi, refining qi into shen, and refining shen back to emptiness.
18 However, according to orthodox Daoist cultivation techniques, it is divided into five stages:
1) Preserving jing, qi and shen
2) Stabilizing jing, qi and shen
3) Nurturing jing, qi and shen
4) Replenishing jing, qi and shen
5) Transforming jing, qi and shen. Finally, there is the replenishment of jing, bone marrow and brain [to nourish the spiritual body].
19 During cultivation, if we can follow these five stages, it will help us at least get rid of illness and extend our lives. With modest level of attainments, we can reverse the aging process (recover the pure yang bodies of chaste youth).
20 With higher levels of attainment, we can gain everlasting life. When the body and the spirit have been transformed, we smash the void and become one with nature.
21 Of course, it has never been easy for one while in the chaste body of youth to nurture his primal energy by bypassing worldly passions. Should he follow this method of cultivation, he can yield results very quickly. He could bring great attainments within three years.
22 Most middle-aged people are physically compromised. Their blood and qi are failing, and their bodies are depleted. They must hurry to adopt a practice that will allow them to graft on or restore that which has been lost.
23 For the elderly, this is even more difficult, so they must begin by replenishing their jing, qi and shen:
1) Do not have outflows of jing, qi, or shen
2) Do not injure jing, qi, or shen
3) Do not agitate jing, qi, or shen.
24 Though your external yang may be in abeyance, it could still be regenerated through tempering so that you could recover the pure yang body you had in your youth, and continue cultivating from that point on.
25 Compromised bodies, as stated earlier, need to replace what had been lost. This refers to a yin-yang union of the acquired body within you, going back to what is innate. It is the joining of ‘lead’ [yang] and ‘mercury’ [yin]. Do not get the wrong idea that I am speaking of sexual practices.
26 Whether the joining is done spiritually or energetically through qi, this is a concept that ordinary people are not sure about. To talk of replenishment by joining with the opposite sex is a deception, and an affront to higher truth and reason.
27 The genuinely transmitted Daoist style of Chinese Original Quiet Sitting, which is discussed in this book, is a matter of holding true yin and true yang in one’s own body.
28 To merge the true water and the true fire in one’s body is up to oneself to bring them into alignment. There is absolutely no need for yin or yang from somewhere else. In no way can it be replenished by someone of the opposite sex.
29 In urban setting is not the right place to induce your qi by guiding it through visualization. It is imperative to control your present bodily envelope to keep progressing continuously.
30 Paying attention to labor on tempering the mind and sweeping it clean of all delusive or vulgar thoughts. Going into a trance-like state and letting the workings of qi proceed naturally. In this way, we can become in accord with the workings of the heavenly body.
31 God’s creation of the universe is through natural laws.
32 Some scientists claim that the universe was created 280 million years ago.
33 Recently an American astronomer found that the space containing the universe is constantly expanding, not shrinking. Thus stars of galaxies throughout space will never collide, and the universe will not be destroyed.
34 These wonderfully profound laws of nature happen to be the same fundamental principles by which Daoists cultivate self-nature and physical body simultaneously.
35 A few years ago the Central Daily Newspaper printed an editorial: “Work to Save the World with a Spirit That Transcends the World.” In it is a passage that confirms what I say about the dual cultivation of self-nature and physical body.
36 The occasion for the editorial was when President Jiang Jingguo [aka Chiang Ching-kuo], received leaders of various religions. The passage said:
37 “Albert Einstein once made this pronouncement: ‘However great the inventions of the future, they cannot leap beyond the sphere of social morality and spiritual life.
38 Because our study of science has advanced to the natural laws outside our bodies, we should turn about and search for the inner laws of life.’
39 The inner laws of life are spirit, our own spirituality and our moral codes. These are also the principles of seeing into one’s original nature, of embracing the Dao and upholding benevolence to others.”
40 This shows that when science backs itself into a corner, we need inner cultivation that lifts us to a higher spiritual realm.
41 When Einstein spoke of the “inner laws of life,” perhaps he meant that the human physiology, psychology, spirit and flesh must be in harmony with each other. Their development should be in balance so that there is harmony between spiritual and material life.
42 This is the highest ideal of the Chinese people: the union of heaven and mankind.
43 The great Dao has always been perfectly even-handed, and does not allow selfishness.
44 Through the ages, people intented on studying the Dao have climbed mountains and forded streams, wandering like clouds in the sky and seeking out enlightened teachers.
45 Sometimes they were fortunate to find a lofty person who would instruct them and impart to them some memorable verses. Sadly, often they begin diligently, but tire in the end. Without a tough regimen of cultivation, all their earlier efforts would be in vain.
46 This is why the personal rewards of quiet sitting can only be savored by oneself, according to the extent of one’s own effort. They cannot be described with words.
47 And that is the idea behind the saying: “The drinker of water knows if the water is warm or cold.”
 Jing, qi, and shen can be roughly translated as "bodily essence, vital force, and animating spirit." These three should not be viewed as separate substances. Rather, they can be seen as functions of a living unity. According to Lu Hsi-hsing's commentary on the Heart Seal Scripture, "What is numinous and aware is called shen; what energizes and works in cycles is called qi and what gives moist richness to cause growth is called jing." Briefly, shen regulates, qi operates and jing generates.
 Five grains refer to rice, beans, wheat, soybean and yellow millet.