Whether the human character is good or evil depends on which one of the Li-xing, Qi-xing, and Zhi-xing 14 dominates.
The Li-xing is the essence of Tao as well as the soul of a human. It is all good and has no evil.
The Qi-xing is the yang side of the Tai-ji, 12 which is evolved from Tao, and the property of a human’s Hun. 16 It sometimes is pure and sometimes contaminated. Therefore, it can be good or evil.
The Zhi-xing is the yin side of the Tai-ji and the property of a human’s Po. 16 It is all desires for materialism and all evils without any goodness.
If one’s Li-xing dominates, he will act in accordance with the five virtues of Tao. Everything he does will always conform to the “center and harmony”.
If his Qi-xing dominates, he may be good sometimes and evil at other times.
If his Zhi-xing dominates, he will be deeply pulled by materialism and the consequence is that his temperament will is almost all evil and hardly any good.
When Mencius said that the original human character is all good, what he described is the Li-xing of the soul.
When Gao-zi said that the original human character can be good or evil, what he described is the Qi-xing of the Hun.
When Xun-zi said that the original human character is all evil, what he described is the Zhi-xing of the Po.
By stressing the Li-xing over the Qi-xing, Mencius is honored as a Saint.
Stressing the Qi-xing, Gao-zi did not understand the Li-xing, and could only be honored as a Sage.
Stressing the Zhi-xing and the desires for materials, Xun-zi did not understand either the Li-xing or the Qi-xing, and he was neither a Saint nor a Sage, but an ordinary person.
the three Confucian scholars expressed their concepts regarding the original human character differently because of the different level of understanding of Tao.