The immortal of the Tang Dynasty, but the game starts at Xuanwu Gate?

Let's rewind a little bit, to outside the school.

Two unexpected people met here.

"Erlang, what are you doing here?" Changsun Wugou looked at the person opposite her with surprise in her eyes.

Li Shimin coughed and said, "I came to see how Huai'an is doing with his teaching. After all, Chengqian is the future crown prince, so I have to be careful... But you, Guanyinbi, what brings you here?"

Empress Zhangsun raised her eyebrows slightly, pursed her lips, and gave an intriguing expression.

"Erlang, are you truly concerned about Chengqian's studies?"

Li Shimin said earnestly, "Of course, Guanyinbi, you know my expectations for Chengqian, and with Huai'an taking Chengqian to do those things... how could I not pay attention?"

Empress Zhangsun pressed, "Really?"

"really!"

Empress Zhangsun remained silent, only gazing meaningfully at Li Shimin with her lips tightly closed.

Li Shimin pretended for a while, but couldn't keep it up any longer. His lips curled down as he tried his best to suppress his laughter.

The two exchanged a silent glance, and then, in perfect unison, began eavesdropping.

At that moment, they happened to hear Li Chengqian asking Chen Huai'an about the social classes of scholars, farmers, artisans, and merchants.

After listening carefully to the first two answers, the couple nodded in unison.

Changsun Wugou lowered her voice and said, "Second Brother, Chen Huai'an has profound insights into scholars and farmers, and he has pointed out their respective importance almost incisively."

"Not bad." Li Shimin couldn't help but nod.

To be honest, Chen Huai'an's insight was not surprising. What surprised him was that Li Chengqian actually remembered what he had said back then.

This greatly pleased Li Shimin.

He secretly made up his mind that he would definitely raise Chengqian to be a perfect successor.

"Wrong, the importance of labor is no less than that of scholars and farmers..."

Inside the school, Chen Huai'an's resounding words echoed, causing Li Shimin and Empress Zhangsun to simultaneously become serious.

"Erlang, is craftsmanship just as important as agriculture?"

Li Shimin pondered and said, "I do not deny the importance of craftsmanship, but to say that craftsmanship is no less important than that of scholars and farmers... I find it hard to agree."

"Agriculture is the foundation of the nation. Although industry is useful, it is not as essential to the people's livelihood as agriculture."

"Confucianism also emphasizes that a gentleman is not a tool; although it is indispensable, it is ultimately a 'minor skill'."

Empress Zhangsun first nodded in agreement with Li Shimin's words, then said, "But Chen Huai'an seems to have a different opinion."

"He seems to highly value work."

Li Shimin hesitated for a moment: "Let's hear it first!"

"Industry is essential for the benefit of the people and the foundation of a strong nation..."

Inside the school, Chen Huai'an's words came again, and Li Shimin's eyes narrowed, somewhat puzzled.

Was Chen Huai'an's statement too harsh?

If industry is the foundation of a strong nation, what are scholars and farmers?

Despite thinking this, Li Shimin didn't question anything; he still had that much patience.

Until Chen Huai'an asked that question.

Why did the Stone Age end? What appeared that rendered it obsolete? And what rose to prominence?

This question not only made Li Chengqian and others in the school ponder, but also stunned Empress Zhangsun and Li Shimin, who were eavesdropping outside the window.

However, Li Shimin quickly figured out the answer to the question.

"Is it bronze, sir?"

Li Chengqian tilted his head back and voiced his conjecture.

"good!"

Chen Huai'an was very pleased: "It was bronze that rendered the Stone Age obsolete!"

"This is the second major advancement in technology. The first was the advent of stone tools, which gave humankind the ability to change the world."

"And what revolutionary changes did the emergence of bronze bring?"

Another question was raised.

Li Chengqian pondered for a long time but still couldn't come up with an answer, not to mention Cheng Chumo and the others.

Outside, Li Shimin was initially puzzled, but then, as if struck by a sudden thought, he became breathless, gripped the windowsill tightly, and his face flushed with excitement.

"So that's how it is! So that's how it is!"

"Erlang, what are you thinking about?" Changsun Wugou, who was standing to the side, asked immediately upon seeing this.

Li Shimin's voice trembled slightly: "I'm not sure if I'm right. I've never looked at this issue from this perspective before, but now I think I understand. I want to hear what Huai'an has to say!"

"If it's really as I think, then Huai'an's words are true!"

"Industry is a resource that benefits the people and is the foundation of a strong nation!"

"..."

"Sir, I don't understand." Li Chengqian lowered his head in shame.

"It's okay if you don't understand. A person who admits they don't understand and humbly seeks knowledge is far superior to someone who pretends to know," Chen Huai'an explained patiently with a faint smile.

Stone tools are heavy, difficult to shape, not tough enough, not sharp enough, and not durable enough.

"The appearance of bronze solved these problems instantly."

"Production capacity thus saw a leap forward. Bronze agricultural tools, such as sickles and hoes, were several times sharper and more durable than stone tools. People could use these tools to cultivate more farmland and harvest more grain."

"When there is a food surplus, the population begins to rise rapidly!"

"At the same time, the emergence of bronze also led to an absolute monopoly on military power..."

Correct!

That's it!

Li Shimin was thrilled that his conjecture had been confirmed.

Empress Zhangsun, standing nearby, found it amusing, unsure whether Li Chengqian or Li Shimin was the student.

Why does Li Shimin now seem so much like a student receiving praise from his teacher?

"Guanyinbi," Li Shimin said in a low voice as he listened, "I was right after all. Next, Huai'an should be talking about bronze weapons."

"The first empire was born at the same time as the invention of bronze weapons."

"It was indeed an absolute monopoly of military power, because at that time, whoever controlled the raw materials and casting techniques possessed absolute military power."

"Huai'an is right, this is a revolutionary change."

"Why didn't I think of that before?"

Li Shimin suddenly felt as if the fog of history was dissipating before his eyes, and he had finally glimpsed a corner of the truth.

This feeling... is so captivating.

Seeing her husband's delighted expression, Empress Zhangsun couldn't help but chuckle softly, "Second Brother, are you secretly learning, or are you attending lessons for Chengqian?"

Li Shimin came to his senses, his old face flushed slightly, and he said seriously, "I was just... too eager to have a son, and also too eager to have talent."

"Is that so?" Empress Changsun smiled, not exposing his lie any further, and turned to look into the classroom. "Shall we continue listening?"

Li Shimin did not answer, but simply put his ear closer.

In the classroom, Chen Huai'an continued, "...The emergence of bronze weapons allowed a small group of people to wield martial power far exceeding that of ordinary people."

"They used these weapons to conquer tribes and establish city-states, and thus the first dynasties and states were born."

"Think about it, would all of this have happened without the breakthrough in bronze-making technology?"

"Or did it happen that quickly?"

"......"