Pestilence and Plague

"In China's traditional calendar system, which is commonly known as the lunar calendar..."

Su Ziyang turned around, wrote the words "lunar calendar" on the blackboard, and then wrote the words "leap month".

"The Chinese lunar calendar includes leap months. For example, 2020 was the Gengzi year, and it had a leap fourth month, meaning that the traditional China calendar had 13 months, or two fourth months in the lunar calendar."

As Su Ziyang spoke, he gave an example, specifically an example of a leap month.

"Therefore, the number of days in a year actually varies, and this difference in the number of days in a year leads to changes in the overall environment each year. If the difference is too large, infectious diseases will occur (what the Yellow Emperor's Inner Canon calls epidemic diseases)."

This is what the "Treatise on the Root of Diseases" in the Yellow Emperor's Inner Canon's Inner Classic refers to as "those who lose their proper place, meaning that although they are in the correct year, they are not in the correct position of their authority, which leads to the disorder of the four seasons and the outbreak of a major epidemic."

Su Ziyang quoted a couple of classic texts, getting increasingly into the mood.

Previously, when Su Ziyang spoke, he admired people like Mr. Mengfei who could use classical Chinese phrases in their speech. Now, feeling inspired, Su Ziyang suddenly found himself speaking them as well, and the feeling was exceptionally satisfying.

Upon hearing Su Ziyang mention the key point, both Qi Chu and Mr. Mengfei couldn't help but smile.

"Each epidemic that occurred was categorized in the * Yellow Emperor's Inner Canon * into five types: 'metal, wood, water, fire, and earth,' which are named after the Five Elements resulting from the combination of the ten Heavenly Stems."

The ten Heavenly Stems combine as follows: Jia and Ji combine to form Earth, which governs Earth's fortune; Yi and Geng combine to form Metal, which governs Metal's fortune; Bing and Xin combine to form Water, which governs Water's fortune; Ding and Ren combine to form Wood, which governs Wood's fortune; and Wu and Gui combine to form Fire, which governs Fire's fortune.

As Su Ziyang spoke, he wrote the Five Movements in the order of mutual generation on the blackboard.

"Here, I'll recite a passage from the original text and give you an example to help you better understand the theoretical basis here."

The "Treatise on Root Diseases" in the * Yellow Emperor's Inner Canon * discusses in detail the consequences of five types of failed combinations. Here is an example, as detailed below. "For instance, if the Yang energy of the Renwu year is excessive, and the Heavenly Stem of the Xinsi year is also excessive, even after the Renwu year, the Jueyin still governs Heaven, while Earth has already shifted to its proper position, and Yangming is in the Earthly Branch. Last year, the Bingshen year, the Shaoyang acted as the right intermediary, meaning Heaven is Jueyin and Earth is Yangming, hence Earth does not obey Heaven. When Ding and Xin combine, the Wood element Great Void, and Metal prevails over Wood, therefore it is not..." Excessive, that is, the tube of Ruibin, too horn does not respond, metal moves dry and prevails, fire transforms into heat and relapses rapidly, slightly, it is a plague that spreads to all sizes, good and bad, the year the plague arrives is determined by the celestial number and Taiyi. Also, just like Ren to Wu, it should be handed over to the official to govern, that is, Dingyou below has not been transferred to the correct position, that is, Bingshen below the lesser yang has not been withdrawn, seeing that Ding and Ren are not in harmony, that is, Ding is soft and the stem loses its strength, also the wood element is slightly weak, there is a small victory and a small relapse. Three years later, it transforms into a plague, called wood plague, its appearance is like a wind plague, the treatment is as before.

Su Ziyang put in a lot of effort to memorize this passage. After lunch, Qi Chu and Mr. Mengfei went for their afternoon nap.

Su Ziyang didn't have much time, so Su Ziyang had to rely on his exceptional memory accumulated over the years to barely manage to impress his two masters.

"Yes, you're a promising student!"

Qi Chu gave Su Ziyang a very high evaluation in his heart.

To better understand this passage, the sixty-year cycle is listed below, and an image is created:

To better understand this passage, the sixty-year cycle is listed below.

Su Ziyang began writing the sixty-year cycle diagram on the blackboard.

Actually, counting the sixty Jiazi cycles is very easy. Here's a simple method for you.

First, write the ten heavenly stems "A, B, C, D, Wu, Ji, Geng, Xin, Rengui" into six rows.

Then write the Earthly Branches under each Heavenly Stem. Since there are ten Heavenly Stems and twelve Earthly Branches, two Heavenly Stems will be written in the next row. But that's okay, just keep writing them in a loop.

Continue writing until all six rows are filled.

Below, look at the two characters side by side: Jiazi, Yichou...

A, B, C, D, E, F, G, H, I, G.

Zichou Yin Mao Chen Si Wu Shen You

A, B, C, D, E, F, G, H, I, G.

Xuhaizi Chou Yinmao Chen Si Wu Wei

A, B, C, D, E, F, G, H, I, G.

Shen Youxu Haizi Chou Yinmao Chensi

A, B, C, D, E, F, G, H, I, G.

Wu, Wei, Shen, You, Xu, Hai, Zi, Chou, Yin, Mao

A, B, C, D, E, F, G, H, I, G.

Chen Si Wu Wei Shen Youxu Hai Zi Chou

A, B, C, D, E, F, G, H, I, G.

Yin Mao Chen Siwu Wu Shen Youxuhai

Su Ziyang wrote the sixty-year cycle on the blackboard and then continued his lecture.

"In our base area, we'll first write down the Five Movements and Six Qi of a year using the sixty-year cycle, and then we'll continue our analysis."

Su Ziyang wrote several years on the blackboard, "Xin Si, Ren Wu, Gui Wei, Jia Shen, Yi You, Bing Xu, Ding Hai" (seven years).

The analysis based on the original text is as follows:

Xin Ren Gui Jia Yi Bing Ding

Si, Wu, Wei, Shen, You, Xu, Hai

The combination of Ding and Ren transforms into Wood, which governs the Wood element. Yang represents excess, while Yin represents deficiency.

The year of Xin Si: Jueyin Wind Wood governs the heavens, Water Movement (Shaoyu), and Shaoyang Ministerial Fire resides in the earth.

Renwu Year: Lesser Yin Fire governs the heavens, Wood element (Taijiao), Yangming Dry Metal resides in the earth.

After writing down these basic facts, Su Ziyang began to explain the content and calculation methods.

"When the year preceding Renwu (壬午) is Xinsi (辛巳), which is a leap year as mentioned earlier, then Xinsi (辛巳) is considered to have an excess of days."

"This means that his ruling qi will not normally hand over on the day of the Great Cold solar term. His ruling qi, Jueyin Wind Wood, will then take over in the Renwu year. Therefore, the ruling qi of the Renwu year, Shaoyin Sovereign Fire, will not have its function, that is, it will not be properly transferred."

This resulted in the Heavenly Stem "Xin" of the Xin Si year replacing "Ren" of the Ren Wu year to combine with "Ding". The normal combination should have been "Ding and Ren combine to form Wood", but because the Xin Si year had more days, the combination of "Xin" and "Ding" was incorrect.

"This result produced what is known as plague. Therefore, because it lacks the wood element that would otherwise be produced, it is called 'wood plague.'"

"If we had this diagram, it would be easier to understand the two sentences in the second paragraph: why 'it is the Dingyou year' and why it is said 'last year, the Bingshen year'."

"As can be seen from the diagram, in the year of Renwu, the year directly opposite it was Dingyou. If we understand it in three dimensions, Renwu is above and Dingyou is below, hence the saying 'below Dingyou'."

"And to the right of Dingyou in Quanzhou is Bingshen, hence the saying that the previous year of Renwu was Bingshen."

As Su Ziyang spoke, he wrote down a few more years next to him and began explaining the next paragraph.

"Let's arrange these years as follows: Bing Shen, Ding You, Wu Xu, Ji Hai, Geng Zi, Xin Chou, Ren Yin, Gui Mao."

Bing Ding Wu Ji Geng Xin Ren Gui

Shen, You, Xu, Hai, Zi, Chou, Yin, Mao

"This situation is similar to the one before, except this time it's Ding Rougan who lost her defenses, and what she lost was transformed into a wood pestilence."

Su Ziyang pointed to the content on the blackboard. "So I won't go into too much detail about this here. By the way, the 'softness' and 'strength' refer to Yin and Yang, with Yin being soft and Yang being strong."

"As can be seen by consulting the perpetual calendar, the Dingyou year had a leap month in the sixth month, which is similar to everything that happened before, so the plague subsided after three years."

According to the Yellow Emperor's Inner Canon's Inner Classic, the symptoms of epidemic diseases are similar, and the key to distinguishing them lies in whether, during the combination of the ten Heavenly Stems, a Yang Stem loses a Yin Stem, or a Yin Stem loses a Yang Stem. The so-called epidemic disease is actually a pair of Yin and Yang. For example, when Xin and Ding combine, Ren (Yang) loses Ding (Yin), meaning Yang losing Yin results in an epidemic; when Bing and Ren combine, Ding loses Ren, meaning Yin losing Yang results in a plague.

After Su Ziyang finished speaking fluently, Qi Chu stood up abruptly, patted Su Ziyang on the shoulder, and whispered, "You did it!"