A live-streamed Chinese language lesson under the sky—the ancients were taken aback.

After the sky darkened, Li Shimin did not return to his bedchamber, but instead found an old memorial.

Wei Zheng's "Ten Gradual Failures to Achieve a Complete End" was submitted in the thirteenth year of the Zhenguan era. It was very harsh, saying that he was not as good as he was in the early years of the Zhenguan era, that his acceptance of advice was declining, and that he had begun to enjoy himself.

He read it and was somewhat displeased, but he still wrote the four characters "Know your mistakes and correct them" and rewarded Wei Zheng.

Reading it again tonight, every word and sentence suddenly carries a different weight.

"Is Minister Fang here?" Li Shimin asked the eunuch beside him.

"The Chamberlain is on duty tonight and is waiting outside the palace."

"Let him in."

When Fang Xuanling entered the palace, he saw the emperor sitting behind a desk with two items spread out beside him.

On the left was an old memorial to the throne, which he immediately recognized as being written by Wei Zheng. On the right was the content recorded by the sky tonight, densely covered with words he couldn't quite understand.

"Sit down." Li Shimin went straight to the point. "I've been thinking about this all night, and I have a feeling that Tianmu is saying that no matter what I do now, there will be problems in the future."

Fang Xuanling opened his mouth, but did not reply.

"I am not doubting what I am doing now," Li Shimin's voice was unusually calm. "I am thinking about a more difficult question. If everything I am doing is right, but the result is still collapse, then the problem is not what I did wrong, but..." He paused for a moment, "but the 'right' itself."

Fang Xuanling finally spoke: "Does Your Majesty mean... that even the right system can become wrong?"

"Yes, Tianmu calls this path dependence. I thought about it for a long time and came up with a word: decay."

It's not bad, it's rotten. When a tree is alive, its wood is tough, but after it dies, even if no one cuts it down, it will slowly rot away.

Not because it did anything wrong, but because time is the enemy of all systems.

He stood up and walked to the map hanging on the wall, the map of the Tang Dynasty glowing dark red in the candlelight.

"My equal-field system is working well now, but what about a hundred years from now? Land is limited, and the population is constantly growing. One day, there won't be enough land to go around."

At that time, the equal-field system will become a dead letter, no longer the foundation of the country.

My Fubing system is not bad now. Where there is land, there are soldiers. The soldiers provide their own clothing and food, and the state hardly spends money to support them. But once the Equal-Field System collapses, the Fubing system will collapse as well.

By then, the imperial court would have no choice but to switch to a conscription system, where soldiers would be professional and loyal to their commanders, not the court.

He stopped.

"Then came the military governors."

Fang Xuanling's face turned pale. He realized that the path the emperor had deduced did not require a foolish ruler or treacherous officials at any step; it only required time.

"I understand now," Li Shimin's voice suddenly lowered, "The hardest thing is not discovering the problem, but finding that you can't solve it at its root after you've discovered it. You can delay it, you can fix it, but you can't stop it."

He turned to look at Fang Xuanling.

Fang Xuanling asked uncertainly, "Is this the inevitable course of history that Tianmu spoke of?"

Li Shimin nodded, then walked back to his desk. "I also saw something in the comments section."

He picked up the notebook, which was filled with words he couldn't quite understand.

"If the changes in production relations cannot keep up with the development of productive forces, it will explode sooner or later," said an observer named Teacher Ma. Another said, "Quantitative change leads to qualitative change, and contradictions drive development." Yet another said, "Things always turn to their opposite."

"I can roughly guess the meaning of these words. The production relations should refer to systems such as the equal-field system and the military system."

Productivity should include agricultural tools, farming methods, population, and land. What Professor Ma meant was that while the system remains unchanged, the underlying factors are changing, and sooner or later the system will be unable to contain these changes.

Fang Xuanling frowned and thought for a long time: "That is indeed a very novel way of putting it."

"It's not just novel." Li Shimin tapped his fingers on the table. "It provides an explanation for why something right can become wrong."

It's not because people have become bad, but because the world itself is changing.

The right thing I did was for the country during the Zhenguan era.

By the time of the Kaiyuan era, the world had changed, and what was right was no longer right.

But at that time, the rulers and their ministers dared not or were unwilling to change the established laws of their ancestors.

As Tianmu said, it's like treating a temporary expedient as a universally applicable eternal truth.

He stopped, looked at Fang Xuanling, and there was a rare hint of earnestness in his eyes.

"What I want to know most right now is not why the Tang Dynasty perished, I have roughly figured that out. What I want to know is how future generations will solve this problem."

"The future?"

"Yes, in the barrage comments on the screen, the viewers didn't seem shocked by the rise and fall of dynasties."

The way they discussed these issues was like a royal physician discussing a common disease.

They have a language I can't understand, things like "contradiction," "quantitative change leading to qualitative change," and "relationships of production."

In their time, there might have been a method I was unaware of.

Fang Xuanling remained silent for a long time.

He stood up and walked back to the map. This time, he didn't look at the frontier, but at Chang'an, the city he had personally planned and expanded.

"Minister Fang, tell me, have I considered my life a success?"

"Your Majesty ushered in the prosperous reign of Zhenguan, which will be admired by all generations."

Li Shimin turned to look at Fang Xuanling.

"In my life, I do not want to be an ordinary emperor. I do not want to be Emperor Yang of Sui, nor do I want to be a ruler who only maintains the status quo. I want to be a great emperor for all time and let the glory of the Tang Dynasty illuminate the world."

I succeeded, but the heavens told me that too much light would bring another kind of danger: light itself would make people unable to see the darkness beyond it.

The most frustrating thing right now is this: I cannot be timid and delay things now just because I am worried about future generations relying on the same path, nor can I abolish the equal-field system just because I am worried that it will collapse in the future.

I can only do what is most right in the present moment, and then hand over a system destined to decay to future generations, hoping they can change it.

Fang Xuanling's tears suddenly welled up; he understood the helplessness in the emperor's unspoken words.

We expect them to be able to change.

But Tianmu said that future generations couldn't change it, or rather, by the time they wanted to change it, it would be too late.

"Your Majesty," Fang Xuanling's voice trembled slightly, "the story of the Heavenly Curtain is not yet finished. Perhaps there will be a turning point later, perhaps future generations will find a solution..."

"I hope so." Li Shimin walked back to his desk, sat down, and picked up his pen.

He unfolded a blank imperial edict and slowly wrote a few lines.

"I have heard that the relationship between Heaven and humanity must be carefully examined. The governance of the three dynasties each had its gains and losses. The Zhou dynasty, learning from the two dynasties, was rich in culture and culture. This was not merely about maintaining the status quo, but about making improvements and additions. Therefore, I have ordered the Imperial Academy to compile the 'Study on the Gains and Losses of Institutions,' which will record the evolution of institutions from ancient times to the present, detail their gains and losses, and trace their origins and development."

He lowered his head again and added another line at the end of the edict.

"A ruler must be ignorant of Heaven and must fear history. Knowing Heaven means knowing the times, and fearing history means knowing the signs of change. Knowing the times and knowing the signs of change, even if one cannot rule forever, one can at least leave no shame before posterity."