Offering salt and sugar aroused suspicion among the court officials.

Liu An gladly accepted Li Zhi’s proposal. He found himself increasingly fond of studying natural philosophy with Li Zhi, especially relishing the tension that came with exploring the unknown.

After their success with refined salt, extracting white sugar became a remarkably simple task. By merely repeating the process of filtering brine several times, they obtained some snow-white sugar. During this endeavor, they also produced a considerable amount of brown sugar.

When Li Zhi presented refined salt, brown sugar, and white sugar to Emperor Taizong, Li Shimin was so astonished and delighted that he was at a loss for words to express his joy. These two commodities were essential to the livelihood of the people; for the citizens of the Great Tang, being able to use high-quality, affordable sugar and salt was a great blessing.

Li Shimin could not wait to take the refining method from Li Zhi’s hands and immediately shared the good news with Fang Xuanling and the others. What Li Zhi did not know was that, due to the Tang Dynasty’s backward sugar-making techniques, Li Shimin had been preparing to send envoys to distant India to learn the craft. Yet, even Indian methods could not produce the granulated sugar that Li Zhi had made.

Fang Xuanling and his peers, upon seeing the refined salt and sugar, marveled at Li Zhi’s talent. In just over ten days, Li Zhi had already contributed three remarkable inventions for the benefit of the nation and its people, not even counting his outstanding work on revising the legal code.

After a brief moment of joy, Fang Xuanling’s face grew serious as he voiced his concerns. He said to Li Shimin, “Your Majesty, I do not know if I should speak, but I have something to say.”

Li Shimin, still in high spirits, waved his hand dismissively and replied, “Fang, if you have something to say, speak freely.”

Fang Xuanling spoke, “Your Majesty, His Highness the Prince of Jin’s recent outstanding performance has provoked much discussion in the court. Some officials are now questioning the security of the Crown Prince’s position.”

After these words, he glanced at Wang Gui and Li Jing, and saw that both had furrowed their brows upon hearing this.

Li Shimin's expression immediately darkened. He spoke with a hint of anger, “What does Zhinü’s excellence have to do with the Crown Prince’s position? Do they think I would replace the Crown Prince because of this?”

Fang Xuanling replied, “Your Majesty, forgive my frankness, but His Highness the Prince of Jin’s achievements have far surpassed what is expected of any child prodigy. This is beyond anything anyone could have imagined.”

Li Shimin gave a cold snort. “So what? My gifted child has always been exceptional—should I deliberately suppress him for it?”

Fang Xuanling hastily denied this, “Your Majesty misunderstands. The only reason the officials are concerned is that they cannot believe that His Highness the Prince of Jin truly possesses such abilities.”

Li Shimin sneered, “Absurd. Which of Zhinü’s achievements was not unprecedented? Does someone think I am secretly helping him?”

With that, he shook his sleeve and cast a sharp glance over the three ministers.

He continued, “If I truly had such capable people by my side, would I not have rewarded their merit rather than let them be overshadowed by my youngest son?”

Upon hearing this, the three quickly voiced their denial. Everyone knew that Li Shimin was renowned for recruiting talent and rewarding merit, which was precisely why so many of the empire’s talents flocked to his side. He would never do anything to destroy his own reputation.

Wang Gui spoke, “Your Majesty, since some ministers already doubt the Prince of Jin’s abilities, why not give His Highness a chance to demonstrate his prowess before the court? That would silence the rumors.”

Li Shimin retorted angrily, “How should he demonstrate? Should we have someone supervise every aspect of Zhinü’s life?”

Wang Gui quickly clarified, “That is not what I meant.” He continued, “Since His Highness is so passionate about natural philosophy, why not let him guide the craftsmen at the Directorate of Works…”

He was about to say more, but Li Shimin interrupted him furiously, “Absolutely not. Zhinü’s interest in natural philosophy is only a passing fancy. Should I send him to labor at the Directorate of Works for that?”

Wang Gui tried to persuade him, “Your Majesty, please do not be angry. I only suggest this to silence the rumors, lest idle gossip disrupt the harmony between the Crown Prince, Your Majesty, and the princes.”

Li Shimin’s expression changed instantly. The thing he most dreaded these days was any mention of fraternal strife. The shadow of the Xuanwu Gate Incident still lingered, its repercussions not yet settled. Even his own father had yet to forgive him.

Li Shimin felt a deep sense of helplessness. How closely did Li Zhi’s current situation resemble his own youth? Both had displayed extraordinary talent among their brothers early on, only to become the target of powerful factions in court, and eventually to be suppressed by their own brothers. In the end, driven to the brink, he himself had launched the Xuanwu Gate Incident.

Thinking of this, he turned to the three ministers and asked, “Zhinü is not yet three years old—a mere child, precocious perhaps, but does that warrant such censure from the entire court?”

He drew a deep breath and said through clenched teeth, “I will not allow anyone to sow discord among my sons. Anyone who dares to spread malicious rumors—I will have them executed.”

The three ministers’ faces changed at these words. Li Jing, who had been silent until now, quickly interjected, “Your Majesty, please calm yourself. The matter is not so severe. All that is needed is for His Highness the Prince of Jin to prove his abilities.”

Li Shimin sneered, “How ridiculous. Even if Zhinü proves himself, what then? Will it be as it was with me in the past?”

He continued, his face clouded with memory, “Will they say Zhinü is heaven’s chosen? That he is more suited to be Crown Prince than Gaoming?”

All three present had lived through the Xuanwu Gate Incident. Hearing Li Shimin’s words, they fell into silence. Strictly speaking, the events of that time were indeed greatly exacerbated by the machinations of the ministers. It was their relentless suppression of Li Shimin and his loyalists that had pushed him to launch the Xuanwu Gate Incident.

Fang Xuanling was the first to break the silence. “Your Majesty, in my opinion, it would be best to allow His Highness the Prince of Jin to demonstrate his abilities. Only then can it be shown that Your Majesty has never favored him.”

Wang Gui added, “Once the Prince of Jin’s talents are proven, those who are ignorant of the truth will naturally be silenced.”

Li Jing joined in, “At that point, if there are still those who dare to gossip, Your Majesty can then punish them severely.”

Hearing their words, Li Shimin forced a bitter smile. Though their advice sounded reasonable, he knew well that the reason such rumors had taken hold was because even they themselves doubted Li Zhi’s abilities. Even Fang Xuanling, who had spent days in close contact with Li Zhi, was not entirely convinced that these ideas truly originated with the young prince himself.