The Xiongnu problem had long been a persistent headache for the Central Plains states, and since the founding of the Han Dynasty, countless battles were fought against them, with conflicts intensifying during Emperor Wu's reign. Years of military campaigns had gradually drained the Han treasury, leaving the national economy unable to cover its expenses. Emperor Wu urgently needed to increase state revenue, but he could not put additional pressure on the common people, leaving him deeply troubled and uncertain about what to do.
At this time, Sang Hongyang petitioned Emperor Wu, saying he had a way to help the state weather its difficulties and also cover military expenses. Emperor Wu of Han was overjoyed and eagerly asked Sang Hongyang what his good plan was.
Sang Hongyang was exceptionally business-minded. His family had been merchants for generations and was the wealthiest household in Luoyang, so from a young age he absorbed knowledge of wealth creation through constant exposure. Despite his family's riches, Sang Hongyang did not inherit the family business but chose to become an official instead. At the age of thirteen, he was selected as a Palace Attendant and entered the court, serving by Emperor Wu of Han's side. He told Emperor Wu that there were many profitable trades among the people, such as salt and iron.
Since the founding of the Han Dynasty, salt boiling and iron smelting were controlled by wealthy local merchants. Salt and iron were essential daily necessities for the people, so these merchants' businesses grew larger and larger, gradually monopolizing the salt and iron trade across the country and amassing countless fortunes. Sang Hongyang suggested to Emperor Wu of Han that the salt and iron trade be changed to state monopoly, which would not only curb the power of local wealthy families but also rapidly boost the state's fiscal revenue. Emperor Wu approved this reform and promoted Sang Hongyang several ranks in office; ultimately, Sang Hongyang, as Imperial Censor, took charge of the nation's economic development.
After Emperor Wu of Han passed away, Emperor Zhao of Han ascended the throne. Before his death, Emperor Wu entrusted Huo Guang and Sang Hongyang with assisting the young emperor in governing the state. Huo Guang and Sang Hongyang held vastly different ideologies; Huo Guang revered Confucianism and advocated for benevolent governance, while Sang Hongyang championed Legalism, leading them to form opposing factions during Emperor Wu's reign, irreconcilably at odds. By this time, Sang Hongyang's economic reforms had been implemented for a long while, and Huo Guang had repeatedly proposed abolishing the state monopoly on salt and iron, promoting policies of rest and recovery for the people with lighter taxes and corvée labor, which further strained their already tense relationship.
After arguing for a long time without reaching a consensus, Huo Guang simply summoned many virtuous scholars and held a meeting with Sang Hongyang's faction specifically to discuss the salt and iron issues. This became known as the Salt and Iron Debate.
Before convening the meeting, Huo Guang sent several officials to visit the common people, both to seek out virtuous and talented individuals and to investigate the people's living standards, hoping to gather more favorable evidence to prove the drawbacks of the salt and iron monopoly.
In 81 BCE, virtuous and learned scholars selected from across the country arrived in Chang'an, marking the official start of the Salt and Iron Debate. These scholars argued that the government monopoly on salt and iron would cause hardship for the common people, while Sang Hongyang and Prime Minister Tian Qianqiu firmly opposed abolishing the monopoly, leading to a fierce debate between the two sides.
Worthy scholars and literati argued that during the state monopoly on salt and iron, some officials deliberately raised prices or lowered quality to line their own pockets, with the common people bearing the brunt of the harm. Some government-sold salt had a bitter taste, so people refused to buy it and had to flavor their meals with plain water; iron tools were expensive, yet the knives made from them could barely cut through weeds, forcing farmers to pull weeds out by hand. These examples showed that the salt and iron monopoly essentially enabled the government to extort money from the people, and thus such state-controlled industries should be abolished and handed over to the people, which would truly benefit the nation and its citizens.
Sang Hongyang, however, believed that to increase national revenue, the state must firmly control the economy; otherwise, the dynasty would gradually decline and lack the ability to counter foreign invasions.
Beyond the discussion of salt and iron, the two sides also debated the national situation of the time. The first issue was the Xiongnu problem: whether to seek peace with the Xiongnu or use military force to suppress them. The virtuous scholars and literati argued that seeking peace was better than war, as war exhausted the people and drained resources. They advocated for a policy of marriage alliances (heqin) to ease relations between the two states, using benevolence, righteousness, and ritual to influence the Xiongnu. They also proposed lifting the heavy military presence in border towns to truly allow the people to rest. Sang Hongyang's faction disagreed, holding that the Xiongnu were naturally barbaric and unreasonable, that marriage alliances could only ensure temporary peace without fully subduing them, and that a firm crackdown was the best way to guarantee the safety of the Han Dynasty.
On the choice of governance methods, the two sides also disagreed. The virtuous scholars proposed that by the end of Emperor Wu of Han's reign, social conflicts had become very prominent, so a policy of appeasement and relief must be adopted to calm the people's grievances, ruling with virtue and benevolence, prioritizing ritual over force—this was the wise approach. Sang Hongyang's faction, on the other hand, insisted on ruling by law, implementing strict punitive measures, and never giving any opportunity to the wicked.
Huo Guang did not participate in the Salt and Iron Debate, but he undoubtedly supported the faction of virtuous scholars and literati. Although the two sides argued fiercely, their starting point was the same: to better govern the country. It can be said that while they differed in ideology, their goals were identical.
After the Salt and Iron Conference concluded, Emperor Zhao of the Han Dynasty did not completely abolish the government monopoly on salt and iron but instead banned a portion of the exclusive sales. Although the scope of reform was small, it still weakened the influence of landlords and wealthy merchants to some extent and helped ease social conflicts. Following the conference, the Han Dynasty's economy gradually began to recover, and the Confucian ideology promoted by Huo Guang gained further trust from the rulers.
At first glance, the state monopoly on salt and iron indeed brought many benefits to the country, not only increasing national treasury revenue but also curbing powerful local forces and strengthening central authority, while using military force to suppress the Xiongnu seemed a reliable way to ensure national stability. However, during the Han Dynasty, when social contradictions were acute, overly rigid adherence to these policies only worsened tensions, potentially triggering social unrest and causing the people to lose faith in the court. In contrast, the virtuous scholars and literati, deeply aware of the people's hardships and understanding the struggles of common life, mostly advocated policies aimed at easing social conflicts, which helped in governing the state. Yet it must be understood that everything has its pros and cons, and blindly implementing any policy could also bring adverse effects to the nation.