74: The Great Calendar Reform: Science, Politics, and Dynastic Crisis in China

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Shunzhi (Shun jee) Emperor to Johann Adam Schall von Bell, 1661
“Your law [Christianity ] is already widely spread. Through your exertions the science of astronomy has become known. Thus, Jo-wang, do you labor for the empire. Should not the heart of the Emperor rejoice! You, Jo-wang, know how the empire should be governed. For this reason come to me and we will talk about it. Jo-wang, conserve my words in your heart.”

When Chinese astronomers failed dramatically to predict a solar eclipse on June 21, 1629, Emperor Chongzhen's (Chung jen) immediate response was to establish the Calendar Reform Bureau under Xu Guangqi.

The Calendar Reform Bureau became a battleground and testing site for Western astronomy. During this period, the Ming dynasty faced crises like rebellions, threats from the Manchus on the northern frontier, and institutional decline. Jesuit expertise offered practical solutions and diplomatic leverage. They presented their help as serving China, using their astronomy skills for religious and political access.

Johann Schreck's death in May 1630 was a significant loss to the mission's scientific efforts. This brilliant scholar had been a key member of the Calendrical Bureau. His passing put greater responsibility on Johann Adam Schall von Bell, who was already emerging as a rising figure in the astronomical reform project. 

Born in Cologne on May 1, 1592, Adam Schall von Bell received a Jesuit education emphasizing religious and scientific training. His studies equipped him with key mathematical and astronomical skills for his career in China. The perilous journey to China from 1618 to 1619 exposed him to plague, storms, and mutinies, but also provided important mathematical instruction from Schreck, whose lessons would directly influence Schall's later success in astronomy.

During the period of persecution of Jesuits in China, Schall and others were detained in Macao from 1619 to 1622. This turned out to be fortunate for Schall's understanding of Chinese culture, shaping his personal missionary approach. Guided by experienced missionaries who had experienced persecution and exile, Schall learned the vital lesson that "to preach Christ to the Chinese, the man of the West must himself become a Chinese." 

In 1623, Schall finally arrived in China, adopting the name Tang Jo-wang, wearing scholar's robes, and following Chinese customs. His early astronomical work, notably predicting the October 8, 1623 lunar eclipse, impressed officials, including the finance minister, who wanted to be his "pupil." However, this scientific success caused tensions with cautious mission leaders, who were concerned about the dangers, given recent persecutions of astronomer-minded missionaries.

Schall's personality blended intellectual talent with traits that both propelled and complicated his missionary efforts. Characterized by "boisterous humor" and being "too free and too critical," he was more a pioneer than a diplomatic leader. His wide-ranging intellect—encompassing mathematics, astronomy, law, biblical studies, and numerous languages—enabled him to connect with Chinese scholars on multiple levels. While stationed in Sianfu (Shee aan foe) from 1627 to 1630, he showed strong leadership in establishing a Christian community.

By 1630, Schall's superiors acknowledged his "uncommon character" and "tenacity," which earned him a return to Beijing with honors and a boost to his reputation. His expertise in science, cultural adaptability, and perseverance made him well-suited for the task of calendar reform during the final years of the Ming dynasty. 

By the 1630s, the Ming Dynasty faced an unprecedented convergence of devastating pressures that proved impossible to handle. The Little Ice Age reached its most severe stage during what historians call the "Chongzhen Slough"—the coldest temperatures in nearly 2,000 years, combined with a destructive 19-year megadrought from 1625-1644. The environmental disaster exacerbated the empire's economic weaknesses, particularly its severe reliance on imported silver from Spanish America and Japan.

When Spain's Philip IV cracked down on silver smuggling in the 1630s and Japan adopted its Sakoku isolation policy in 1639, China's silver supply shrank significantly. The silver-copper exchange rate plummeted, making tax collection impossible at a time when resources were most needed. The Single Whip Reform of 1580, which had simplified taxation into silver payments, proved disastrous when silver shortages led to the entire fiscal system collapsing. Peasants found themselves unable to pay taxes in silver while trading locally with increasingly worthless copper coins.

Despite genuine reform efforts after taking power in 1627, Emperor Chongzhen was hindered by deep-rooted institutional damage that no single ruler could undo. His authoritarian style and suspicious nature hindered the formation of stable coalitions necessary for effective crisis management. Additionally, his   decision to eliminate capable generals further eroded military leadership during the critical battles against the Manchu and rebel forces.

Li Zicheng (Lee See chong) emerged amid this chaos, with his personal journey from loyal soldier to revolutionary leader symbolizing the empire's wider collapse. In 1631, he deserted the imperial army after the government failed to resupply his unit, reflecting the broader systemic failure that left hundreds of thousands of soldiers unpaid and abandoned. Originating from Shaanxi (Shaan see) province, Li personally witnessed the destructive impacts of drought, famine, and government neglect that spurred desperate peasants to rebel.

Li's shift from banditry to revolution began in 1635, when he joined twelve other rebel leaders in coordinating their efforts. The extent of popular support became clear as environmental disasters worsened—by 1640, 123 counties faced cannibalism during the worst famine in 500 years. Li adopted the title "Dashing King" in 1636, after his uncle's execution, marked his rise as a prominent rebel leader with real political goals.

The key turning point occurred in 1639 when scholar Li Yan joined the movement, providing the intellectual framework that transformed crude banditry into a systematic peasant revolution. Li Yan (lee yen) expressed the movement's central message: "Equalization of land ownership, exemption from land tax"—a message that resonated strongly with farmers facing impossible tax burdens during environmental disaster. This slogan offered not just relief from immediate hardship but a fundamental reorganization of rural social relations.

Li's conquest of Luoyang (low yong) in 1641 showcased the movement's increasing sophistication alongside its ongoing contradictions. Executing the despised Prince of Fu, who had neglected to supply famine relief despite his wealth, served as a symbol of popular justice against aristocratic indifference. However, Li's troops displayed restraint toward ordinary people while also exhibiting brutal violence toward officials and landlords. This exemplifies the movement's dual nature as both a social revolution and a violent uprising.

The conquest of Xi'an (Shee aan) in 1643, capital of Li's native Shaanxi, marked the apex of his regional power. From there, he proclaimed the Da Shun Kingdom and declared himself emperor, aiming to legitimize the rebellion. However, this revealed weaknesses in Li's leadership that would be fatal in the final campaign.

By early 1644, Li Zicheng led about 300,000 men toward Beijing. The Ming capital's defenses were weakened by decades of decay, corruption, and the purges of the 1620s. The hereditary military system had degraded, leaving only 845,000 actual troops from 3 million official posts, with unpaid soldiers often joining rebellions.

Li's forces reached Beijing on April 23, 1644, with little resistance. The city's fall was due to internal collapse, not siege warfare, as a eunuch, Cao Huachun (sow hwahchun), opened the western gate on April 25, showing the breakdown of imperial authority. The emperor's flight through the city, observed by Schall, ended with his suicide, marking the end of 276 years of Ming rule.

Li Zicheng's entry into Beijing exposed the fatal flaws of his movement. The systematic pillaging that followed demonstrated Li's inability to control his forces, as restraint and order were crucial for establishing a legitimate rule. The breakdown of military discipline alienated potential supporters among Beijing's population, who might have accepted rebel rule if it had offered stability and security.

The rebel administration's efforts to extract wealth from Ming officials through torture and extortion further eroded any chance of gaining the support of the educated classes, whose cooperation was crucial for effective governance. Li's forces turned Beijing into a city under hostile control rather than the capital of a new dynasty, creating the chaos that made Manchu intervention seem more like liberation than foreign conquest.

Most devastatingly, Li captured the father and beloved concubine of Wu Sangui (Woo Sang gway), the commander of the key Shanhai Pass.  This caused Sangui to ally with the Manchus. Shanhai Pass controlled the narrowest choke point in the strategic Liaoxi Corridor (lyou shee), an elongated coastal plain at the foot of the Yan Mountains, and the only easily accessible land route between North and Northeast China. The pass's strategic location meant that, without mounting a costly direct siege, the only way for an invading army to bypass the pass's defenses was to go around it through a few treacherously narrow mountain passes deep within the Yan Mountains. This would make it very difficult to maintain supply lines and any sizable invasion effort. 

Wu Sangui's choice was not just personal revenge but a calculated acknowledgment that Li's forces could neither effectively govern nor safeguard Chinese civilization from further decline.

The Battle of Shanhai Pass on May 27, 1644, shaped China's destiny for the next three hundred years. Although Li Zicheng's troops outnumbered the defenders, they could not withstand the united Manchu-Chinese forces commanded by Wu Sangui and Prince Dorgon. The rebels' military structure, which had been successful against the corrupt Ming army, fell apart when faced with the disciplined Manchu banner system, backed by seasoned Chinese leaders and artillery.

Li's retreat from Beijing was accompanied by orders to burn the city, leading to the destruction of the imperial palace and much of the capital. This final act of destruction symbolized the complete failure of his revolutionary vision—rather than establishing a new order, the rebellion had hastened China's slide into chaos and foreign domination.

Li Zicheng died in 1645 in the Jiangxi mountains under uncertain circumstances, ending China's largest peasant uprising. His movement toppled the Ming Dynasty but failed to establish stable governance.

The Manchu conquest of China originated from centuries of tribal expansion in northeastern China. Nurhaci (Nor ha chi), a Jurchen (Jur jen) leader, unified the Jurchen tribes in Manchuria and formed a strong state in the late 1500s. He developed the Eight Banners military system, which structured Jurchen society around military principles. In 1617, he issued the “Seven Grievances” against the Ming, effectively declaring war. After Nurhaci won the Battle of Sarhu in 1619, the Ming's military strength along the northern border declined. Nurhaci established the Later Jin Dynasty in 1616. He died in 1626 and was succeeded by his son, Hong Taiji.   (Huang Tai ji)

Hong Taiji turned this tribal alliance into a sophisticated political power, declaring the Qing (Ching) dynasty in 1636 and adopting Chinese government models while keeping military dominance. Their plan aimed to legitimize foreign rule over the Chinese people by showing better governance and upholding traditional institutions.

As Li Zicheng's rebels captured Beijing and Emperor Chongzhen committed suicide, Schall faced the challenge of protecting the Christian community and Jesuit assets amid the chaos. He did receive warning notices that provided protection for the Jesuits during the pillage, and his scientific equipment and calendar materials survived systematic arson, which he regarded as miraculous preservation.

Schall made the decision to serve the Manchu rulers rather than flee.  This was a bold risk that would shape Jesuit influence in China. When Dorgon's forces took Beijing, Schall presented himself to the new regime, emphasizing his scientific expertise over his religious mission. The key test was the September 1, 1644 solar eclipse, which proved Western astronomical superiority. Schall's calculations were accurate to the minute, while Chinese astronomers erred by thirty minutes, and Muslim astronomers by an hour, publicly validating Western methods before the new Manchu rulers.

Dorgon recognized the political value of astronomical expertise and appointed Schall as Director of the Imperial Board of Astronomy, despite his initial refusals. This marked an unprecedented level of foreign integration into Chinese administration. Under the young Shunzhi (Shun jee) Emperor, Schall's influence reached extraordinary heights.  Shunzhi was the son of Hong Taiji.  Upon his father’s death, he became the second emperor of the Qing Dynasty and the first Qing to rule over China. He adopted Schall as "Mafa" (grandfather), fostering church building, preaching, and the protection of Christian communities.  

While the Ming Dynasty was falling apart, the Calendar Reform Bureau finished its work under Schall in 1644. Initially, the new calendar was dedicated to Emperor Chongzhen. Now, with new rulers in power, Schall had to navigate political sensitivities and renamed it the Shixian (She shee-en) Calendar ("Book of the Conformity of Time") to hide its connection to the Ming dynasty.  

The project, documented in over 100 volumes, offered an encyclopedic overview of advanced mathematical topics including Euclidean geometry, spherical geometry, and trigonometry. It also extensively translated and referenced foundational Western scientific works by Euclid, Copernicus, Kepler, Galileo, and Tycho Brahe, with the Tychonic astronomical system forming its theoretical basis. The work further included detailed mathematical tables and astronomical data. This calendar would be used from the early Qing period into modern times.

The death of Emperor Shunzhi in 1661 removed the primary protector of Christian missions, creating vulnerability during the regency for the child emperor Kangxi. The regency council, dominated by conservative Manchu nobles, was vulnerable to factional pressure and anti-foreign sentiment that grew during Schall's influence. This shift coincided with cultural anxieties about foreign influence and Chinese traditions.

Yang Guangxian (Yong Gwang shee-en), a seventy-year-old conservative scholar with a history of political failures, became the prominent leader of organized opposition to Jesuit astronomy. Yang's efforts gained dangerous speed when two missionaries published inflammatory writings claiming Christianity was China's original religion and Chinese civilization came from the West, direct violations of Ricci-Schall's careful strategy of cultural respect and adaptation.

Yang's three-pronged attack dismantled Jesuit credibility by accusing them of religious heterodoxy, astronomical incompetence, and political treason. He challenged Western ideas, such as the concept of a spherical Earth, and argued that Christianity was incompatible with Chinese moral values. The most damaging claim linked Schall's astronomical authority to imperial family welfare, alleging his choice of an inauspicious burial date for an imperial prince in 1658 caused the deaths of the prince's parents.

The trial revealed how scientific, political, and religious authority intersected in early Qing China. Schall's stroke in April 1664 left him paralyzed and barely able to speak, requiring fellow Jesuit Ferdinand Verbiest to act as spokesman during the legal proceedings. Despite initial court skepticism about conspiracy charges, ongoing political pressure and bribery gradually overshadowed the evidence and logical arguments. The court's focus shifted from technical astronomical expertise to broader issues of cultural loyalty and imperial security.

The 1665 death sentences—slow slicing for Schall and execution for five Chinese Christian astronomers—demonstrated the political victory of cultural conservatism over scientific merit. The unequal punishments reflected political strategy: foreign Jesuits received different sentences than Chinese converts, allowing the regency to assert authority over both foreign and domestic subjects while avoiding full responsibility for persecuting foreign experts.

In April 1665, a series of natural phenomena presented Chinese officials with a face-saving opportunity to ease the persecution without appearing to yield to Christian influence. A comet appeared on April 13, followed by an earthquake on April 16 and a palace fire on April 29. Jesuit accounts claimed the earthquake happened exactly when the emperor was about to sign Schall's death warrant, but this timing appears to be an embellishment. Both Chinese and Jesuits viewed these events as signs of heavenly disapproval of the persecution, fueling the belief that "God of Christians is upholding his servants." Whether due to real supernatural intervention or clever use of natural coincidences, these events gave political cover to commute the death sentences and allowed Yang Guangxian to take over the Astronomical Bureau.

Yang Guangxian's administration from 1665 to 1668 was a test of Chinese versus Western astronomy. While he removed Jesuit influence, he faced the same technical issues that prompted calendar reform. His admission that he "only knew the principles of calendar but not the mathematics" showed that cultural conservatism failed to handle complex, precise technical systems requiring math and observation.

Yang's failure to produce accurate calendars, including serious errors in his 1670 projection, showed that ideological opposition can't replace scientific skill. The old astronomer families' reluctance to support Yang, despite his efforts to restore traditional methods, revealed how institutional memory and networks had adapted to Jesuit-trained techniques over the course of two decades. Their refusal to abandon effective methods for traditional ones highlighted the practical limits of cultural restoration when it conflicted with technical effectiveness.

The young Kangxi (Kong she) Emperor's personal intervention marked a crucial turning point in the calendar controversy. Taking power at the age of fourteen in 1667, Kangxi strategically utilized the astronomical dispute to demonstrate imperial competence and authority while avoiding direct conflict with powerful regents. His order for systematic testing showed sophisticated political judgment, allowing the dispute to be resolved through empirical evidence rather than ideological decree, thereby establishing legitimacy for his eventual decision while seeming to favor neither Chinese nor foreign interests.

The December 1668 gnomon shadow test provided clear empirical proof of competition between Guangxian and Verbiest. Conducted with twenty high officials as witnesses to ensure transparency and legitimacy, the test required precise predictions of noon shadow lengths cast by a gnomon over successive days. Verbiest's accurate predictions starkly contrasted with complete failures by Chinese astronomers, demonstrating that practical accuracy could prevail over cultural conservatism when imperial needs demanded reliable knowledge.

The results could not be dismissed as foreign cultural imperialism or political manipulation—they represented objective mathematical and observational superiority that any educated observer could verify.

The final decision in 1669-1670 involved fully rehabilitating Schall and the executed Chinese Christians, removing Yang Guangxian, and appointing Verbiest as Director of the Imperial Astronomical Bureau.

This period established the first successful effort of sustained East-West scientific collaboration. Through the Jesuit accommodation strategy—positioning Western science as a service to the Chinese state rather than a means of cultural replacement—figures like Ricci, Schreck, and Schall achieved unprecedented foreign integration into imperial institutions while respecting Chinese frameworks

Beyond its success, the Chinese calendar reform also reflected the fundamental limitations of global knowledge transfer during the Scientific Revolution. While Jesuit missionaries successfully introduced Western astronomical methods to China and created a groundbreaking two-way scientific exchange between East and West, this episode ultimately showed that receiving advanced scientific knowledge did not automatically lead to indigenous scientific revolutions. The reform's emphasis on empirical testing, rather than cultural authority, anticipated the validation methods that would define European scientific societies. However, China remained reliant on European experts instead of building its own autonomous scientific institutions. This pattern—where the Scientific Revolution incorporated global knowledge while establishing European methodologies as the universal standard—demonstrated how 17th-century science was both internationally sourced and European in its institutional foundations. This model would influence global scientific development for centuries to come.

This concludes our series of episodes, not only on the Jesuit scientific exchange in 17th-century China, but also on the larger narrative of the nature of scientific revolutions and the paradigm shift in astronomy that began with Copernicus. In our next episode, we will travel back to Europe and explore aspects of daily life in the 16th century. Our first course will be food and the emergence of a global cuisine.

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