1. On Human Nature:Human nature is neither inherently good nor evil; self-interest is its fundamental nature.

If human nature were inherently good, then everyone would be good—where would evil come from? If human nature were inherently evil, then everyone would be evil—where would goodness come from? Since people exhibit both good and evil, then good and evil cannot be inherent in human nature.

So-called good and evil are merely different choices made by individuals when faced with interests. Those who pursue their own interests without harming others are ordinary people; those who sacrifice their own interests to help others are good people; those who harm others for their own gain, or harm others without gaining anything themselves, are evil people. People often judge whether someone is good or evil based on their choices regarding interests.

Human nature is neither inherently good nor evil; it is self-interested. There is no human who is not self-interested (here, self-interest is a neutral term, neither good nor bad). In an era of scarce resources, if humans were altruistic rather than self-interested, the limited food supply would lead to mutual deference causing mass deaths, thereby threatening the survival of the entire group. For a group to endure, every member must pursue self-interest; otherwise, humanity would have long since vanished. This explains why ancient sages declared that those who do not act for their own benefit invite the wrath of heaven and earth.

Self-interest is not only human nature but the nature of all living beings. For a creature incapable of self-interest cannot exist; every living thing that does exist is inherently self-interested.

Every living thing is driven by a force as constant as gravity, compelling all beings to strive relentlessly for their own survival. Let us call this force that compels all creatures to seek perpetual existence the "will to survive."

For animals, life boils down to two pursuits: finding food and finding mates. No matter the hardship, they never give up. The search for food sustains their physical existence, while the pursuit of mates ensures the continuation of their genetic legacy. All these behaviors are driven by the force of existence.

As a species of animal, humans are likewise driven by this force. The daily activities of people—seeking sustenance and seeking partners—are no different from those of animals. From this perspective, humans and animals share no fundamental distinction.

The difference lies in humanity's pursuit of existence beyond the biological realm, extending into the spiritual. Living on in people's hearts is another way to perpetuate one's existence. This explains why humans strive for immortality in history. For to achieve such immortality means to exist eternally in spirit. The Zuo Zhuan's assertion that one can attain immortality through "establishing virtue, achieving great deeds, and leaving behind words" offers humanity's finest interpretation of spiritual perpetuity.

Driven by the force of existence, humans instinctively strive to ensure their perpetual survival—both physical and spiritual. With this clarity, we better understand why all are captivated by fame and fortune. Seeking fame is the quest for spiritual immortality; pursuing wealth is the drive for physical continuity.

The force of existence compels people to seek food and mates, yet both seem perpetually scarce. Some inevitably vanish due to lack of sustenance or partners. Only when everyone pursues self-interest can each individual strive to survive, thereby ensuring the survival of the entire group.

Constantly driven by the force of existence, which inherently makes human nature self-serving, self-interest is thus the essence of humanity. This essence is neither inherently good nor evil.

Only by acknowledging and understanding this self-interest can we establish systems aligned with human nature to achieve fairness in society. When a system fundamentally contradicts the principle of self-interest, no matter how noble or beautiful its ideals, its practical outcomes will inevitably fall short of its goals—and may even produce entirely opposite social effects. For example, public ownership. When a system directly aligns with the principle of self-interest, it can be implemented smoothly and achieve its intended goals. For instance, private ownership. When a system fundamentally conforms to the principle of self-interest but superficially appears to violate it, its implementation will initially face resistance. However, if it is pursued and demonstrates societal benefits, it can gain widespread acceptance. For example, the abolition of inheritance.