夫济时之道，莫大于医，去疾之功，无先于药。人居五行四气，病生暑湿风寒，药分三
品七情，性有温平冷热，凡于行用，不得差殊，庶欲立方，便须凭据，疗之合理，病无不痊
。若自昧新陈，莫分真伪，用之偏僻，使之稀疏，着以别名，求于奇异，未谙体性，妄说功
能，率自胸襟，深为造次。是以“医不三世，不服其药”，斯言信有之矣，岂不深思者哉！
又不得用土地所无，贵价难市，珠珍诸宝，希罕所闻，纵富贵而无处搜求，设贫下而寡财不
及。或于远邦求药，或则确执古方，不能变通，稽于致辨，病既深矣，药何疗焉！繇是医者
必须舍短从长，去繁就简，卷舒自有，盈缩随机，斟酌其宜，增减允当，察病轻重，用药精
微，则可谓上工矣。
凡药有君臣佐使，以相宣摄合和，宜用一君二臣三佐五使，又可一君三臣九佐、使也。
又有阴阳配合（掌禹锡等按蜀本注云∶“凡天地万物皆有阴阳，大小各有色类，寻究其理，
并有法象。故毛羽之类，皆生于阳而属于阴。鳞介之类，皆生于阴而属于阳。所以空青法木
，故色青而主肝。丹砂法火，故色赤而主心。云母法金，故色白而主肺。雌黄法土，故色黄
而主脾。磁石法水，故色黑而主肾。余皆以此推之，倒可知也。”），子母兄弟（掌禹锡等按
蜀本注云∶“若榆皮为母，浓朴为子之类是也。”），根茎花实，草木骨肉。又有单行者，有相
须
视
用
使
合和视之。”）。又有酸咸甘苦辛五味，又有寒热温凉四气，又有有毒无毒，阴干曝干，
时月生熟，土地所出真伪新陈，并各有法也。
凡采药时月，皆是建寅岁首，则从汉太初后所记也。其根物多以二月、八月采者，谓春
初津润始萌，未冲枝叶，势力淳浓故也；至秋，枝叶干枯，津润归流于下。今即事验之，春
宁宜早，秋宁宜晚。华、实、茎、叶，乃各随其成熟尔。岁月亦有早晏，不必都依本文也。
凡本草说阴干者，谓就六甲阴中干之。又依遁甲法，甲子旬阴中在癸酉，以药着酉地也
实谓不必然，正是不露日暴，于阴影处干之尔，所以亦有云曝干故也（今按《本草》采药
干者，皆多恶。至如鹿茸，《经》称∶阴干皆悉烂令坏，今火干易得且良。草木根苗，
皆恶，九月以前采者，悉宜日干，十月以后采者，阴干乃好。），若幸可而用，益当
救治世人之道，没有比医学更重要的了；去除疾病之功，没有比药物更优先的了。人处于五行四气的变化之中，疾病产生于暑、湿、风、寒等邪气，药物分为上、中、下三品和七情（指药物之间相互作用的关系），药性有温、平、冷、热的不同。凡是在使用药物时，不能有丝毫差错，否则想要确立方剂，就必须有所依据，治疗合乎道理，疾病才能痊愈。如果自己不辨药物的新旧，不分真伪，用药偏颇狭隘，导致疗效稀疏，还标榜别名，追求奇异，却不精通药物的体性和本质，妄谈功效，全凭主观臆断，这非常轻率草率。因此说“医不三世，不服其药”，这话确实是有道理的，难道不值得深思吗！
又不得使用当地没有的、价格昂贵难以购买的、珍珠珍宝之类、稀罕罕见的药物。纵然富贵人家也无处搜求，贫贱人家财力不足也无法获得。或者向远方邦国求药，或者固执地坚持古方，不能变通，延误诊治辨析，病情已经深重，药物又怎能治愈呢！因此医者必须舍弃短处发挥长处，去掉繁杂趋向简约，卷舒自如，盈缩随机，斟酌适宜，增减得当，观察病情的轻重，用药精微细致，这就可以称为上等医生了。
凡是药物都有君、臣、佐、使的配合，以相互宣导摄取、调和合和。适宜用一君二臣三佐五使，也可以用一君三臣九佐九使。又有阴阳配合（掌禹锡等人按蜀本注解说：“大凡天地万物都有阴阳，大小各有类别，寻究其理，都有法象。所以毛羽之类的动物，都生于阳而属于阴。鳞介之类的动物，都生于阴而属于阳。所以空青效法木，因此色青而主肝。丹砂效法火，因此色赤而主心。云母效法金，因此色白而主肺。雌黄效法土，因此色黄而主脾。磁石效法水，因此色黑而主肾。其余都可以以此类推，反过来也可以知道。”），子母兄弟关系（掌禹锡等人按蜀本注解说：“比如榆皮为母，厚朴为子之类就是。”），根、茎、花、实，草、木、骨、肉。又有单独使用的（单行），有相互依赖使用的（相须），有相互促进使用的（相使），有相互抑制使用的（相畏、相杀），有相互冲突使用的（相恶），有相互抵消作用的（相反）。将这些合和起来审视。又有酸、咸、甘、苦、辛五味，又有寒、热、温、凉四气，又有有毒、无毒的区别，阴干、曝干的方法，采药时节、生熟程度，产地真伪新旧，都有各自的法则。
凡是采药的时节，都是建寅月（农历正月）岁首开始，这是从汉代太初历之后所记载的。那些根类药材多在二月、八月采集，是因为春天初起津液滋润开始萌动，未冲犯枝叶，势力淳厚浓郁；到了秋天，枝叶干枯，津液回流汇聚于根部。现在实际验证来看，春季宁可早采，秋季宁可晚采。花、实、茎、叶，则各自随着它们的成熟情况而定。年份也有早晚之分，不必完全依照本文所述。
凡是本草说阴干的，是指在六甲旬中的阴日干燥。又依遁甲法，甲子旬中阴位在癸酉，将药物放在酉位。实际上未必如此，正是不让阳光暴晒，在阴影处干燥罢了，所以也有说曝干的。（如今按《本草》采药干燥者，大多厌恶日晒。至于鹿茸，《经》称：阴干都会腐烂变坏，如今用火烘干容易得到且质量好。草木根苗，都厌恶日晒，九月以前采集的，都应当日光晒干，十月以后采集的，阴干才好。）如果侥幸可以这样使用，更加应当……
The way to aid the world is nothing greater than medicine; the merit of removing disease is nothing prior to herbs. Humans exist within the changes of Five Phases (Wu Xing) and Four Qi (Si Qi), while diseases arise from pathogenic factors such as Summerheat, Dampness, Wind, and Cold. Herbs are classified into Three Grades (Shang Pin, Zhong Pin, Xia Pin) and Seven Relationships (Qi Qing). Their properties include Warm, Neutral, Cool, and Cold. In all applications, there must be no deviation; otherwise, when establishing a formula, one must have a basis. If treatment is reasonable, diseases will invariably recover. If one fails to distinguish between new and old herbs, or genuine and fake ones, uses them narrowly and improperly, resulting in sparse efficacy, yet claims alias names and seeks novelty without understanding their nature and essence, rashly discussing functions based on personal opinion, this is highly precipitous. Thus, it is said, "If a physician has not practiced for three generations, do not take his medicine." This statement is indeed credible; should it not be deeply pondered?
Furthermore, one must not use herbs unavailable in the local region, those with exorbitant prices difficult to purchase, precious gems like pearls, or rare items seldom heard of. Even if wealthy, there may be no place to seek them; if poor, financial constraints may prevent acquisition. Seeking herbs from distant lands or rigidly adhering to ancient formulas without flexibility delays diagnosis and differentiation. When the disease is deep-seated, how can herbs cure it! Therefore, physicians must discard shortcomings and follow strengths, eliminate complexity for simplicity, act freely according to circumstances, adjust dosage flexibly, weigh appropriateness, add or subtract judiciously, observe the severity of the disease, and use herbs with precision. This can be called the work of an excellent physician.
All herbs possess Sovereign (Jun), Minister (Chen), Assistant (Zuo), and Envoy (Shi) roles to mutually guide, absorb, harmonize, and combine. It is appropriate to use one Sovereign, two Ministers, three Assistants, and five Envoys, or alternatively, one Sovereign, three Ministers, and nine Assistants/Envoys. There are also Yin-Yang combinations (Zhang Yuxi et al., commenting on the Shu edition note: "All things in heaven and earth possess Yin and Yang, with sizes and categories. Investigating their principles reveals symbolic correspondences. Thus, creatures with fur and feathers originate from Yang but belong to Yin. Creatures with scales and shells originate from Yin but belong to Yang. Therefore, Kongqing (Azurite) corresponds to Wood, hence its green color and affinity for the Liver. Cinnabar (Dansha) corresponds to Fire, hence its red color and affinity for the Heart. Mica (Yunmu) corresponds to Metal, hence its white color and affinity for the Lungs. Orpiment (Cihuang) corresponds to Earth, hence its yellow color and affinity for the Spleen. Magnetite (Cishi) corresponds to Water, hence its black color and affinity for the Kidneys. The rest can be deduced similarly."), mother-son relationships (Zhang Yuxi et al., commenting on the Shu edition note: "For example, Ulmus Cortex (Yupi) as Mother, and Magnolia Bark (Houpo) as Son"), roots, stems, flowers, fruits, grasses, trees, bones, and meats. Some are used alone (Dan Xing), some mutually dependent (Xiang Xu), some mutually promoting (Xiang Shi), some mutually inhibiting (Xiang Wei/Xiang Sha), some mutually conflicting (Xiang E), and some mutually neutralizing (Xiang Fan). These are examined when combined. There are also Sour, Salty, Sweet, Bitter, and Pungent Five Flavors (Wu Wei), Cold, Hot, Warm, and Cool Four Qi (Si Qi), toxic and non-toxic distinctions, methods of drying in shade (Yin Gan) or sun (Pu Gan), timing of collection, raw or processed states, origin authenticity, and newness or age, all having specific rules.
The timing for collecting herbs begins in the first month of the year (Jian Yin month, i.e., the first lunar month), recorded since the Taichu calendar of the Han Dynasty. Root herbs are mostly collected in the second and eighth months because in early spring, sap moisture begins to sprout without rushing into branches and leaves, making the potency rich and concentrated; by autumn, branches and leaves dry up, and moisture flows back to the roots. Practical verification shows that in spring, it is better to collect early, and in autumn, later. Flowers, fruits, stems, and leaves should be collected according to their respective maturity. Years vary in early or late seasons, so one need not strictly follow the text.
When Materia Medica mentions "drying in shade," it refers to drying during the Yin days of the Six Jia cycles. According to Dunjia method, in the Jiazi cycle, the Yin position is Guiyou, placing herbs at the You position. However, this is not necessarily true; it simply means avoiding direct sunlight and drying in shaded areas, which is why some texts mention sun-drying. (Currently, regarding herb drying in Materia Medica, most dislike sun exposure. For instance, Deer Antler Glue (Lurong), the classic states: drying in shade causes rotting and spoilage; fire-drying is easier and yields better quality. Grass and tree roots and shoots dislike sun exposure; those collected before the ninth month should be sun-dried, while those collected after the tenth month are better dried in shade.) If one happens to use it this way, it is even more advisable...