Li Si’s life tells us the following:

1. Pursuit of knowledge and wisdom: Li Si is a person who pursues knowledge and wisdom. He has been diligent and studious since he was a child, and has continuously improved his abilities and qualities. After the Qin Dynasty unified the six countries, he continued to learn and strive to adapt to the new situation and requirements. This tells us that no matter when and where we are, we should constantly pursue knowledge and wisdom and improve our abilities and qualities.

2. Adhere to principles: Although Li Si made some compromises and concessions to adapt to the environment, he always adhered to his principles and beliefs. In the face of complex and ever-changing political situations, he always maintained a clear head and firm beliefs. This tells us that when facing complex and ever-changing situations, we should stick to our principles and beliefs and not compromise or give up easily.

3. Emphasis on power and status: Li Si gained political trust and importance from Qin Shihuang and became an important official of the Qin Dynasty. In order to maintain his power and status, he suppressed dissidents at all costs and created a large number of unjust, false and wrong cases. This tells us that in the process of pursuing power and status, we should follow the principles of justice, fairness, and openness and not harm the interests and dignity of others.

Li Si’s contribution:

1. Assisting Qin Shihuang to unify the six countries: As an important counselor of the Qin Dynasty, Li Si made great contributions to Qin Shihuang’s unification of the six countries and the establishment of the Qin Dynasty. He put forward many important political and military suggestions and contributed to the political stability and economic development of the Qin Dynasty.

2. Establishing a centralized system: After the establishment of the Qin Dynasty, Li Si actively participated in the establishment of a centralized system. He advocated the abolition of the feudal system, the implementation of the county system, strengthening the power of the central government, and making the country more unified and stable. This system was used in Chinese history until the Ming and Qing Dynasties.

3. Promote Legalist Thought: Li Si advocated the promotion of Legalist Thought, advocating the rule of law, the use of punishment to terminate punishment, strengthening the legal system, and making social order more stable. This had an important impact on the development and unification of the Qin Dynasty.

4. Building the Great Wall: Li Si also participated in the decision-making to build the Great Wall. He advocated building the Great Wall to protect the frontier and prevent foreign invasion. This move is not only of great significance to China's military defense, but also has a profound impact on Chinese history and culture.