养生者之言曰∶天下之人，皆可以无死。斯言妄也，何则？人生自免乳哺以后，始而孩
，既
也。则绝嗜欲，可以无死乎？或者曰∶劳动贼之也。则戒劳动，可以无死乎？或者曰∶思虑扰
之也。则屏思虑，可以无死乎？果能绝嗜欲，戒劳动，减思虑，免于疾病夭札则有之。其老
而， 而死犹然也。况乎四十以前，未尝无嗜欲、劳苦、思虑，然而日生日长。四十以后
，虽无嗜欲劳苦、思虑，然而日减日消。此其故何欤？盖人之生也，顾夏虫而却笑，以为是
物之生死，何其促也，而不知我实犹是耳。当其受生之时，已有定分焉。所谓定分者，元气
也。视之不见，求之不得，附于报导血之内，宰乎气血之先。其成形之时，已有定分焉。所
谓定分者，元气也。视之不见，求之不得，附于气血之内，宰乎气血之先。其成形这时，已
有定数。譬如置薪于火，始燃尚微，渐久则烈，薪力既尽，而火息矣。其有久暂之殊者，则
薪之坚脆异质也。故终 无病者，待元气之自尽而死，此所谓终其天年者也。至于疾病之人
，若元气不伤，虽病甚不死；元气或伤，虽病轻亦死。而其中又有辨焉。有先伤元气而病者
，此不可治者也；有因病而伤元气者，此不可不预防者也；亦有因误治而伤及元气者；亦有
元气虽伤未甚，尚可保全之者，其等不一。故诊病决死生者，不视病之轻重，而视元气之存
亡，则百不失一矣。至所谓元气者，何所寄耶？五脏有五脏之真精，此元气之分体者也。而
其根本所在，即《道经》所谓丹田，《难经》所谓命门，《内经》所谓节节之旁中有小心，
阴阳合辟存乎此，呼吸出入系乎此。无火而能令百体皆温，无水而能令五脏皆润。此中一线
未绝，则生气一线未亡，皆赖此也。若夫有疾病而保全之法何如？盖元气虽自有所在，然实
与脏腑相连属者也。寒热攻补，不得其道，则实其实而虚其虚，必有一脏大受其害。邪入于
中，而精不能续，则元气无所附而伤矣。故人之一身，无处不宜谨护，而药不可轻试也。若
夫预防之道，惟上工能虑在病前，不使其势已横而莫救，使元气克全，则自能托邪于外；若
邪盛为害，则乘元气未动，与之背城而一决，勿使后事生悔，此神而明之之术也。若欲与造
化争权，而令天下之人终不死，则无是理矣。
养生的人说：“天下的人，都可以做到不死亡。”这种说法是荒谬的。为什么呢？人从断奶以后开始成长，先是孩童，接着成年。那么，杜绝嗜好和欲望，就可以不死亡吗？有人说：“是因为过度劳累伤害了身体。”那么，避免劳累，就可以不死亡吗？又有人说：“是因为思虑过多扰乱了心神。”那么，摒弃思虑，就可以不死亡吗？如果真的能做到杜绝嗜好欲望、避免劳累、减少思虑，免除疾病和早夭或许还有可能。但是年老体衰而自然死亡的情况依然无法避免。况且人在四十岁以前，并非没有嗜好、劳苦和思虑，然而身体却日益生长壮大；四十岁以后，即使没有嗜好、劳苦和思虑，身体却依然日渐衰退消瘦。这是什么原因呢？大概人的生存，就像夏虫一样短暂，人们嘲笑它生命短促，却不知道其实人的生命也是如此。当人受孕形成生命之时，就已经有了既定的定数。所谓既定的定数，就是元气（维持生命活动的根本能量）。它看不见，摸不着，依附于气血之中，主宰在气血运行之前。当形体形成之时，也已有既定的定数。所谓既定的定数，就是元气。它看不见，摸不着，依附于气血之内，主宰在气血之先。当形体形成这时，已经有了定数。这就好比把柴火放在火上，刚开始燃烧时火势微弱，时间久了火势就猛烈，柴火的精力耗尽后，火也就熄灭了。之所以有长久和短暂的差别，是因为柴火的坚硬与脆弱质地不同。所以，终身无病的人，是等待元气自然耗尽而死，这就是所说的享尽天然寿命的人。至于患病的人，如果元气没有受损，即使病情严重也不会死；如果元气已经受损，即使病情轻微也会死亡。其中又有区别：有先损伤元气而后患病的，这是不可治疗的；有因病而损伤元气的，这是必须预防的；也有因为误治而损伤元气的；也有元气虽然受损但还不严重，还可以保全的，情况不一。所以诊断疾病判断生死的人，不看病的轻重，而看元气的存亡，这样就能百无一失。至于所谓的元气，寄托在哪里呢？五脏各有五脏的真精，这是元气的分部体现。而其根本所在，就是《道经》所说的丹田，《难经》所说的命门，《内经》所说的“节之旁中有小心”，阴阳的开合存乎于此，呼吸的出入系乎于此。这里没有火却能令全身温暖，没有水却能令五脏滋润。此中一线生机未绝，则生命的活力一线未亡，都依赖于此。至于有病时如何保全元气的方法呢？大概元气虽然自有其所在，但实际上与脏腑是相连属的。寒热攻补等治疗方法，如果不掌握正确的方法，就会导致实证更实、虚证更虚，必然有一脏受到严重伤害。邪气侵入体内，精气不能接续，那么元气就没有依附之处而受伤了。所以人的全身，无处不应当谨慎保护，药物不可以轻易尝试使用。至于预防之道，只有高明的医生能在病势形成之前进行预判，不让病势已经猖獗而无法救治，使元气能够保全，那么自然能将邪气排斥在外；如果邪气盛大有害，就要趁着元气尚未动摇，与之背城借一决一胜负，不要使后来产生悔恨，这是神妙高超的技术。如果想要与造化争夺权力，让天下的人都最终不死，那是没有道理的。
Proponents of health preservation claim: "All people in the world can achieve immortality." This statement is absurd. Why? After weaning, human beings begin to grow, first as infants and children, then as adults. Would eliminating desires and passions lead to immortality? Some might say: "It is labor that harms the body." Would avoiding labor lead to immortality? Others might say: "It is excessive thinking that disturbs the mind." Would abstaining from thinking lead to immortality? If one could truly eliminate desires, avoid labor, and reduce thinking, it might be possible to avoid disease and premature death. However, natural death due to old age would still occur. Moreover, before the age of forty, people are not devoid of desires, toil, and worry, yet their bodies continue to grow and strengthen; after the age of forty, even without desires, toil, or worry, the body continues to decline and wither. What is the reason for this? Essentially, human life is fleeting, like a summer insect. People laugh at its brevity, unaware that human life is similarly finite. At the moment of conception, a fixed destiny is already established. This so-called fixed destiny is Yuanqi (Primordial Qi, the fundamental energy sustaining life). It is invisible and intangible, residing within Blood and Qi, and governing them prior to their movement. When the physical form is shaped, a fixed destiny is also established. This fixed destiny is Yuanqi. It is invisible and intangible, residing within Blood and Qi, and governing them prior to their movement. When the form is complete, there is already a set number. This is like placing firewood on a fire: initially, the flame is small; over time, it grows fierce; when the fuel is exhausted, the fire extinguishes. The difference in duration depends on whether the wood is hard or brittle. Therefore, those who remain healthy throughout their lives die only when their Yuanqi naturally exhausts itself; this is what is meant by fulfilling one's natural lifespan. As for those who are ill, if Yuanqi is unharmed, severe illness will not cause death; if Yuanqi is damaged, even mild illness may prove fatal. There are distinctions among these cases: some have their Yuanqi damaged prior to contracting disease, which is incurable; some damage their Yuanqi due to disease, which requires prevention; some damage their Yuanqi due to misdiagnosis or improper treatment; and some have slightly damaged Yuanqi that can still be preserved. Thus, physicians diagnosing disease and determining life and death should focus not on the severity of the disease but on the presence or absence of Yuanqi, thereby achieving near-perfect accuracy. Where does Yuanqi reside? Each Zang organ possesses its own True Essence (Zhen Jing), which represents a part of Yuanqi. Its root lies in what the Daoist scriptures call Dantian (Elixir Field), what the Nanjing (Classic of Difficult Issues) calls Mingmen (Gate of Life), and what the Neijing (Inner Canon) describes as "the careful heart beside the joints." Yin-Yang opening and closing depend on this, and respiration enters and exits through this. Without fire, it warms all parts of the body; without water, it moistens the five Zang organs. As long as this thread of vitality remains unbroken, life persists, relying entirely on this. How, then, should one preserve Yuanqi when diseased? Although Yuanqi has its specific location, it is intrinsically connected to the Zang-Fu organs. If cold, heat, purgative, or tonifying treatments are applied incorrectly, excess conditions become more excessive and deficiency conditions more deficient, inevitably causing severe harm to one Zang organ. Pathogenic factors enter internally, and Essence cannot replenish, leaving Yuanqi without attachment and thus injured. Therefore, every part of the human body must be carefully protected, and medicinal drugs should not be taken lightly. Regarding prevention, only skilled physicians can anticipate disease before it manifests, preventing the pathogen from becoming rampant and incurable. If Yuanqi is fully preserved, it will naturally expel pathogens outward; if pathogens are abundant and harmful, one must strike decisively while Yuanqi remains intact, avoiding future regret. This is the divine and illuminating art of medicine. To contend with Nature (Zaohua) and ensure no one ever dies is simply impossible.