Confucius inspired a humanistic and ethical outlook that was developed further by prime disciples Mencius and Xunzi. This development took place amidst the background of arguments against other thinkers or in response to their criticisms of Confucianism. However, there was a disagreement within the Confucian school, as well, as shown by Xunzi’s critique of Mencius. It may be perceived that Mencius has the dominant position in the Confucian tradition as Mencius’s belief that human nature is originally good has often been interpreted into certain sayings of Confucius. Additionally, Xunzi’s claim that human nature is “evil” and that people can be transformed to become good may be inconsistent, as they imply Mencius’s claim that human nature is inherently good. For this reason, it is crucial to analyze both thinkers separately as integration of one thinker’s original thought to another may obscure the important aspects of the assimilated thinker’s position. Secondly, this method of analysis will show that the debate is not one conducted from extreme opposites as it may seem at first sight, for both Mencius and Xunzi agreed that man must cultivate his goodness consciously regardless of whether he is born with it or acquires it from the state. The differences in their views on human nature lead to the ultimate difference of interpretation of the betterment of human nature. Although both philosophers had differences, their ultimate goal was to suggest that human beings can be good and this is what the state needed in such a crucial time in China’s history. To elaborate further on human nature, it is crucial to look at its development within each philosopher’s teachings.
Mencius, being the idealist that he was, believed in the innate goodness of man. He believed that man's ability to learn how to be a good and responsible citizen stems from and thrives upon his innate goodness. If man were not innately good, Mencius argued, how could he possibly learn to be a good citizen? (De Bary 142) Mencius nevertheless maintained that the individual must cultivate and the state must nurture, guide, and help maintain his goodness (De Bary 123). For Mencius, the “great person is one who does not lose the child’s mind” (De Bary 141). Thus, in order to be a worthy nobleman, man should carry his childlike innocence and simplicity into his adulthood. Mencius believes that in the original nature of man there are tendencies that would prompt him to act in a moral way:
The goodness of human nature is like the downward course of water. There is no human being lacking in the tendency to do good, just as there is no water lacking in the tendency to flow downward. Now by striking water and splashing it, you may cause it to go over your head, and by damming and channeling it, you can force it to flow uphill…It is the force that makes this happen. While people can be made to do what is not good, what happens to their nature is like this (De Bary 147).
Additionally:
The trees on Ox Mountain were once beautiful. But being situated on the outskirts of a large state, the trees are hewn down by axes. Could they remain beautiful? Seeing this barrenness, people suppose that the mountain was never wooded. But how could this be the nature of the mountain? So it is also, with what is preserved in a human being: could it be that anyone should lack the mind of humaneness and rightness?
These passages establish that Mencius regards human nature as innately good. To say that human nature is good; however, is not to say that all people behave well. To guide human beings toward goodness is like guiding a stream of water to flow downward. Just as the natural tendency of water is to flow downward, so the natural tendency of human beings is to be benevolent and good. Indeed Mencius agreed that he lived in decadent times rife with evil as various states competed violently against one another for mastery of China, however, the question is not whether evil flourishes; it is whether evil is “natural” or a perversion.

Xunzi was a skeptical thinker; known for his theory that human nature tends toward evil, he argued forcefully for the importance of ritual and education. Although Xunzi’s theory seems to directly contrast Mencius’s, they had much more in common than their differences. Xunzi’s most famous essay begins as follows:

Human nature is evil; goodness derives from conscious activity. Now it is human nature to be born with a fondness for profit…[o]ne is born with feelings of envy and hate, and, by indulging these, one is led into banditry and theft, so that the sense of loyalty and good faith with which one was born disappears. One is born with the desires of the ears and eyes and with a fondness for beautiful sights and sounds, and, by indulging these, one is led to licentiousness and chaos, so that the sense of ritual, rightness, refinement, and principle with which one was born is lost…[t]herefore one must be transformed by the example of a teacher and guided by the way of ritual and rightness before one will attain modesty and yielding, accord with refinement and ritual, and return to order. From this perspective it is apparent that human nature is evil and that its goodness is the result of conscious activity” (De Bary 180-1).

Noticeably, Xunzi does not refute Mencius’s claim that human beings are born with certain emotions that can lead to morality. The question is then, why he comes to the opposite conclusion about human nature:

Mencius said, the fact that human beings learn shows that their nature is good. I say this is not so; this comes of his having neither understood human nature nor perceived the distinction between the nature and conscious activity…[r]itual and rightness are created by sages: people learn them and are capable, through effort, of bringing them to completion. What cannot be learned or acquired by effort but is within us is called the nature. What can be learned and, through effort, brought to completion is called conscious activity” (De Bary 181).

This passage holds the key to the disagreement between Mencius and Xunzi: they have different understandings of the general concept of nature. Mencius’s understanding of the nature of anything is that it is innate and unique to that species. Thus, human nature also constitutes moral inclinations or “moral potentials inherent in each person” (De Bary 115). These moral potentials are classified as the “four beginnings”

Mencius believes in the “four beginnings – natural tendencies within all human beings that, he believes, can be cultivated and developed into the capacities for humaneness, rightness, propriety, and wisdom” (De Bary 115). However, Xunzi defines the concept of nature as that which is innate and does not require effort to complete. For Xunzi, only innate and spontaneous developed traits can count as human nature, such as selfish and violent emotions rather than moral inclinations. Thus, the fundamental difference between Mencius and Xunzi on this point concerns their definitions of the word nature. Due to their different definitions of nature, the process by which man becomes good or maximizes the goodness within him is different. The difference between them on the score of individual betterment is that for Mencius it is a matter of cultivation or nourishment, while for Xunzi it is a matter of “transformation” (De Bary 182). Without the external influence of sages and teachers to effect that transformation, human beings continue to indulge their selfish and violent emotions.

Like bent wood that must be laid against a straightening board, steamed, and bent into shape before it can become straight, only exposure to the teachings and rituals of the sages and moral examples of teachers can counter the natural tendency towards “evil” and pave a path toward individual betterment (De Bary 161). Xunzi emphasizes such transformation through the system of education – he wants people to develop into good people, not just know the facts. The object of transformation is the nature that all persons are born with including the desires for benefit, sensory, and dispositions to feelings such as envy and hate. The sage kings therefore devised ritual principles to establish social order and keep desires in check (De Bary 181). Xunzi argues that every man has the ability to become a sage, but the reason an individual does not become a sage is because he does not exert himself to his full potential. Thus, Xunzi not only makes room for, but also accounts for, the fact that there are people who behave morally and people who behave immorally. Xunzi’s thesis that human nature is evil and that individual betterment comes about through transformation is based solely on the view that an analysis of human nature shows that if something is not done to it, it leads inevitably to strife.

Mencius highlights the innate goodness with human nature and therefore believes that human beings all have a sense of right and wrong and that it is possible for them to do the right thing by cultivating the natural tendencies that furnish human nature. However, Mencius believes that the senses are something that can lead one astray from betterment. The senses are impulsive and do not have the capacity to reflect on what is proper and improper. By contrast, the mind has the capacity to reflect on what is proper, and has the capacity to halt any course of action it regards as improper. The mind should constantly exercise these capacities to ensure that one progresses in an ethical direction (De Bary 129). Right actions may cause the vital energy of the human body to expand, but wrong actions may cause the vital energy of the human body to contract. Each person's vital energy may expand or contract, depending on whether he or she performs right or wrong actions. If a person allows his or her vital energy to expand through righteous action, then his or her vital energy may eventually become a “vast, flowing qi...born from an accumulation of rightness” which enables each person to follow the path of individual betterment (De Bary 127). However, there are other factors can interfere with one's ethical development.

Certain forms of problematic desires may also lead one astray. For example, in a series of dialogues between Mencius and King Xuan of the state of Qi, the king referred to his great desire to expand territories and even to his feverish desires for wealth and a display of valor. These desires not only led the king to harsh policies, but also led him to engage in rationalizations about how he lacked the ability to be caring toward his people. Mencius's response was to try to steer the king toward a more caring policy that was incompatible with the king’s desires but enables cultivation of the human nature (De Bary 122-123). Mencius’s purpose was only to show that men have natural motives to do good. These natural motives are literally a “beginning,” which need cultivation before they can become strong motive forces. Mencius’s idea of cultivation serves to show that although individuals may be corrupt to the extent of doing nothing when seeing a child fall into a well, they are not so corrupt as to feel nothing. Mencius referred to the “four beginnings” as “sprouts” (De Bary 127). These fragile moral capacities need considerable protection, attention and cultivation in order to mature to the point where they inform and direct a majority of our actions.

According to Mencius, we begin life with a minute moral understanding. Xunzi disagrees with the ideology of the “sprout” and denies that we are endowed with a moral sense. Xunzi believes that individuals should follow the sages who discovered and developed the human culture and moral ways. Unlike the sages, most people, in Xunzi’s opinion, would have to endure a transformation process such as learning. We do not know what morality is until we come to understand how we fit into the world at large. Such an understanding, according to Xunzi, is beyond our innate abilities; it is something we must acquire from tradition under the guidance of proper teachers. Regardless of Mencius’s and Xunzi’s contrasting views on human nature and individual betterment, they agree on many fundamental Confucian beliefs. Neither Mencius nor Xunzi endorsed the idea of a dominating government. A stable state was only possible as a reciprocal endeavor; the rulers provide the example to which the citizens respond positively by individual morality and good will. Amidst this great debate between Mencius and Xunzi on human nature, during the Warring States Period, the underlying goal was the restoration of a united China under a strong yet benevolent dynasty.