Short answer
Islam teaches that every child is born pure, on the fitra: a nature made to know its Lord. The Prophet Muhammad (ﷺ) said it is the parents who make the child a Jew, a Christian or a Magian (a Zoroastrian). This answer is neither of the two famous Chinese ones. Mengzi (Mencius) taught that human nature tends to good, as water flows downwards. Xunzi taught that it is bad, and that goodness must be made by training. The Qur'an says God (﷾) showed every soul its wrong and its right. Whoever purifies the soul succeeds, and whoever corrupts it fails. No one is born guilty of another's sin, and no one is born bad. But goodness does not grow by itself: each person must choose. God's (﷾) message uncovers the fitra when life has covered it. The Qur'an asks to be read and weighed with care.
Full explanation
Confucius left the question open
Confucius (Kongzi) said that by nature people are nearly alike, and that practice makes them grow wide apart. He did not say whether that nature is good or bad. The English here is James Legge's. Confucius's followers argued over the question for centuries, and two answers became famous.
“The Master said, 'By nature, men are nearly alike; by practice, they get to be wide apart.'”
Mengzi: nature tends to good, as water flows down
Mengzi (Mencius) taught in the fourth century BCE. A thinker called Gaozi (Kao) said human nature is like whirling water. Open a channel to the east and it flows east; open one to the west and it flows west. Mengzi replied that water may go east or west, but it always flows down. He said human nature tends to good in the same way. When people do wrong, he said, their nature has been forced, as struck water leaps over your forehead. Zhu Xi (Chu Hsi) was a later Confucian teacher. He read this to mean the nature is good, and must be gone against before anyone does evil.
“Water indeed will flow indifferently to the east or west, but will it flow indifferently up or down? The tendency of man's nature to good is like the tendency of water to flow downwards. There are none but have this tendency to good, just as all water flows downwards.”
“Now by striking water and causing it to leap up, you may make it go over your forehead, and, by damming and leading it, you may force it up a hill;--but are such movements according to the nature of water? It is the force applied which causes them. When men are made to do what is not good, their nature is dealt with in this way.”
Mengzi: the virtues are in us from birth
Mengzi said that every person feels pity, shame, respect, and a sense of right and wrong. He said these feelings are the principles of four virtues. They are ren (benevolence, a kind heart), yi (righteousness), li (propriety, the proper rites and manners) and zhi (knowledge or wisdom). These are not put into us from outside, he said; we are born with them. But they must be sought, or they are lost.
“Benevolence, righteousness, propriety, and knowledge are not infused into us from without. We are certainly furnished with them. And a different view is simply owing to want of reflection. Hence it is said, "Seek and you will find them. Neglect and you will lose them."”
Xunzi: nature is bad, and goodness is made
Xunzi (Hsün K'ing), a Confucian of the third century BCE, argued against Mengzi by name. He said people are born loving gain, with envy and with the desires of the eyes and ears. Followed, these lead to strife. So goodness, he said, comes by deliberate effort (wei), as a crooked stick is pressed straight. It comes through teachers and through the rites made by the sages. Yet Xunzi also said that anyone on the road can become like Yu, a sage king of old. Every person, he said, can know what is right and is able to do it.
Xunzi says that human nature is bad, and that its goodness is the result of deliberate effort (wei). People are born loving gain, with envy and dislike, and with the desires of the eyes and ears. Followed, these lead to strife and disorder. So people need the transforming work of teachers and laws, and the way of the rites and righteousness. A crooked stick must be pressed in a frame before it is straight; so human nature must be put under teachers and laws. These were made by the deliberate effort of the sages, as a potter makes a pot; they did not come from human nature. Xunzi calls nature what is in people without being learned or worked for. In their nature, he says, the sages are no different from anyone else; what sets them apart is their deliberate effort. Xunzi argues against Mencius by name. He also says that any person on the road can become like Yu, a sage king of old, because every person has the capacity to know benevolence, righteousness, law and rectitude, and the means to practise them.
Islam's answer: every child is born on the fitra
The Prophet Muhammad (ﷺ) said every child is born on the fitra. It is the parents who make the child a Jew, a Christian or a Magian (a Zoroastrian). He compared this to an animal born whole, with no part cut off. The Qur'an calls the fitra the pattern on which God (﷾) made mankind. It joins it to turning one's face to the true faith. So at the heart of the fitra is a nature turned towards its Lord. It is not a set of lessons: the Qur'an says we came from our mothers' wombs knowing nothing. Nor is any child born guilty of another's sin. No bearer of burdens bears the burden of another. Islam does not say that people never sin. Each person has desires to master and a real choice, and sin comes from these. Adam and his wife did wrong, then turned to God (﷾), and God (﷾) turned to Adam. His children do not inherit his guilt. They may take the same way back, for God (﷾) is Oft-Returning, Most Merciful. The page "Are children born in sin? Does Islam believe in original sin?" says more.
Abu Hurayra reports that the Prophet (ﷺ) said every child is born upon the fitra, the true faith, and it is his parents who make him a Jew, a Christian or a Magian, just as an animal gives birth to a whole young one: do you see any of them born mutilated?
“So set thou thy face steadily and truly to the Faith: (establish) Allah's handiwork according to the pattern on which He has made mankind: no change (let there be) in the work (wrought) by Allah: that is the standard Religion: but most among mankind understand not.”
“It is He Who brought you forth from the wombs of your mothers when ye knew nothing; and He gave you hearing and sight and intelligence and affections: that ye may give thanks (to Allah).”
“Say: "Shall I seek for (my) Cherisher other than Allah, when He is the Cherisher of all things (that exist)? Every soul draws the meed of its acts on none but itself: no bearer of burdens can bear the burden of another. Your goal in the end is towards Allah: He will tell you the truth of the things wherein ye disputed."”
“They said: "Our Lord! We have wronged our own souls: If thou forgive us not and bestow not upon us Thy Mercy, we shall certainly be lost."”
“Then learnt Adam from his Lord words of inspiration, and his Lord Turned towards him; for He is Oft-Returning, Most Merciful.”
Shown its wrong and its right, with both paths open
The Qur'an says God (﷾) gave the soul its proportion and order, and its enlightenment as to its wrong and its right. The Arabic word for "its wrong" is fujur, wickedness. Al-Tabari, with Ibn Abbas, reads it to mean that God (﷾) made clear to the soul both evil and good. Then the Qur'an says that whoever purifies the soul succeeds, and whoever corrupts it fails. It says God (﷾) showed man the Way, whether he be grateful or ungrateful. It says God (﷾) has shown him the two highways. Ibn Mas'ud said these are good and evil. The Qur'an also names real weaknesses. It says man was created very impatient, fretful when evil touches him and stingy when good comes. Then it says, "Not so those devoted to Prayer". It says the soul is prone to evil, unless God (﷾) bestows His mercy. Yet it does not call human nature wicked: it says man was created in the best of moulds. So a person is made to know God (﷾). He has desires to master. And he will answer for what he chooses.
“By the Soul, and the proportion and order given to it; And its enlightenment as to its wrong and its right;-”
On "and inspired it with its wickedness (fujur) and its righteousness (taqwa)", al-Tabari says God made clear to the soul what it should do and what it should leave: good or evil, obedience or disobedience. He gives the same reading from Ibn Abbas ("He made clear the good and the evil"), Mujahid, Qatada and al-Dahhak.
“Truly he succeeds that purifies it, And he fails that corrupts it!”
“We showed him the Way: whether he be grateful or ungrateful (rests on his will).”
“And shown him the two highways?”
“Truly man was created very impatient;- Fretful when evil touches him; And niggardly when good reaches him;- Not so those devoted to Prayer;-”
“"Nor do I absolve my own self (of blame): the (human) soul is certainly prone to evil, unless my Lord do bestow His Mercy: but surely my Lord is Oft-forgiving, Most Merciful."”
“We have indeed created man in the best of moulds, Then do We abase him (to be) the lowest of the low,- Except such as believe and do righteous deeds: For they shall have a reward unfailing.”
“So set thou thy face steadily and truly to the Faith: (establish) Allah's handiwork according to the pattern on which He has made mankind: no change (let there be) in the work (wrought) by Allah: that is the standard Religion: but most among mankind understand not.”
Why a message from God (﷾) is still needed
A good start can be covered over. Mengzi himself said the virtues are lost by neglect. A conscience tells us that right and wrong are real. But people fill in the details from their own time and wants, and Xunzi's rites were made by men. Islam teaches that the One who made human nature has also spoken to it. The Qur'an calls the faith that fits the fitra "the standard Religion". God (﷾) speaks by inspiration, from behind a veil, or by sending a messenger. The page "If we have a conscience, why do we need a message from God?" says more.
“Benevolence, righteousness, propriety, and knowledge are not infused into us from without. We are certainly furnished with them. And a different view is simply owing to want of reflection. Hence it is said, "Seek and you will find them. Neglect and you will lose them."”
“So set thou thy face steadily and truly to the Faith: (establish) Allah's handiwork according to the pattern on which He has made mankind: no change (let there be) in the work (wrought) by Allah: that is the standard Religion: but most among mankind understand not.”
“It is not fitting for a man that Allah should speak to him except by inspiration, or from behind a veil, or by the sending of a messenger to reveal, with Allah's permission, what Allah wills: for He is Most High, Most Wise.”
A whole way of life, and an invitation
Islam is a deen, a complete way of life: belief, worship, law, family and character together. God (﷾) says He has perfected it and chosen it for us. The Qur'an tells believers to enter it whole-heartedly. It asks you to consider the Qur'an with care: had it come from anyone but God (﷾), you would find much discrepancy in it. Its Messenger, Muhammad (ﷺ), was sent to all people, and he is the Seal of the Prophets, the last of them. The page "What is Islam?" shows the whole in one place.
“This day have I perfected your religion for you, completed My favour upon you, and have chosen for you Islam as your religion.”
“O ye who believe! Enter into Islam whole-heartedly; and follow not the footsteps of the evil one; for he is to you an avowed enemy.”
“Do they not consider the Qur'an (with care)? Had it been from other Than Allah, they would surely have found therein Much discrepancy.”
“Say: "O men! I am sent unto you all, as the Messenger of Allah, to Whom belongeth the dominion of the heavens and the earth: there is no god but He: it is He That giveth both life and death. So believe in Allah and His Messenger, the Unlettered Prophet, who believeth in Allah and His words: follow him that (so) ye may be guided."”
“Muhammad is not the father of any of your men, but (he is) the Messenger of Allah, and the Seal of the Prophets: and Allah has full knowledge of all things.”
Three replies answered
Mencius 6A.2 — Book 6, part 1, chapter 2, para 2
“Water indeed will flow indifferently to the east or west, but will it flow indifferently up or down? The tendency of man's nature to good is like the tendency of water to flow downwards. There are none but have this tendency to good, just as all water flows downwards.”
Cited for
Mengzi showed that our nature is good. Keep it and grow it, and you need no prophet.
The response
Islam's answer is the fitra: a nature made to know its Lord (30:30). Mengzi himself says the good in us can be forced aside (6A.2) and lost by neglect (6A.6). He says that whoever knows his nature knows Heaven (7A.1). But he also says that Heaven does not speak; it shows its will through conduct and affairs (5A.5). So, on his own account, no word comes from Heaven to say how to worship, or what comes after death. The Qur'an says God (﷾) has spoken, by sending messengers (42:51). It calls the faith that fits our nature "the standard Religion" (30:30).
Where it lands — Even a sound nature can be covered over. God's (﷾) message calls it back, and tells us what the nature alone cannot.
Qur'an 70:19-22 — Surat al-Ma'arij (The Ascending Stairways), verses 19-22
“Truly man was created very impatient;- Fretful when evil touches him; And niggardly when good reaches him;- Not so those devoted to Prayer;-”
Cited for
Your own Qur'an says man was created very impatient and stingy (70:19-21), and that the soul is prone to evil (12:53). So Islam really holds Xunzi's view: human nature is bad.
The response
Islam's answer is that the Qur'an names weaknesses, not a bad nature. Each verse carries its exception: "Not so those devoted to Prayer" (70:22); "unless my Lord do bestow His Mercy" (12:53). The Qur'an also says, "We have indeed created man in the best of moulds" (95:4). For Xunzi, goodness is not in the nature at all; the sages made it. For the Qur'an, God (﷾) made clear to the soul both its wrong and its right (91:8). Xunzi's cure is the rites the sages made. The Qur'an's cure is turning to God (﷾).
Where it lands — The Qur'an names human weaknesses, and says the soul is prone to evil unless God (﷾) shows mercy. It does not call human nature wicked. Man is made in the best of moulds and shown right and wrong, and turning to God (﷾) masters the weakness.
Analects 17.2 — Book 17, chapter 2
“The Master said, 'By nature, men are nearly alike; by practice, they get to be wide apart.'”
Cited for
Confucius said people are alike by nature and grow apart by practice. So there is no inborn faith, only upbringing.
The response
Islam's answer is that the fitra comes first, and upbringing comes after. The Prophet (ﷺ) said every child is born on the fitra. Then the parents make the child a Jew, a Christian or a Magian (Bukhari 1385). The Qur'an says we were born knowing nothing (16:78). The fitra is not something learned: it is a nature made to know God (30:30). The page "Are children born believing in God?" gives the evidence.
Where it lands — People start from the fitra. Practice and upbringing then make them differ.
Perspectives
Mengzi: human nature is good
Mengzi and the teachers who follow him hold that human nature tends to good. People must keep and grow what they were born with, by learning and reflection.
Mengzi says human nature leans towards good, as water flows downhill. People do wrong only when their nature is forced (Mencius 6A.2).
Rebuttal
Islam's answer is the fitra: a nature made to know its Lord (30:30; Bukhari 1385). A tendency to good does not say what is right in every case. Mengzi says that whoever knows his nature knows Heaven (7A.1). But he also says that Heaven does not speak; it shows its will through conduct and affairs (5A.5). The Qur'an says God (﷾) has spoken, by sending messengers (42:51). It says the soul was shown its wrong and its right, and must choose (91:8-10).
Mengzi says the virtues are not put into us from outside. We are born with them, and we must seek them or lose them (Mencius 6A.6).
Rebuttal
Islam says God (﷾) showed every soul its wrong and its right (91:8). Mengzi says the virtues are lost by neglect, and found again by seeking them (6A.6). The Qur'an says that, but for God's (﷾) grace and mercy, not one believer would ever have been pure (24:21). So the cure is turning to God (﷾), who has spoken (42:51).
Xunzi: human nature is bad
Xunzi holds that people are born with desires that lead to strife. Goodness is made by effort, teachers and the rites of the sages.
Xunzi says people are born loving gain, with envy and with the desires of the senses. Following these leads to strife (Xunzi 23).
Rebuttal
The Qur'an says man was created with weaknesses (70:19-21). But it also says God (﷾) gave every soul the knowledge of wrong and right (91:8). Xunzi himself says every person has the capacity to know what is right, and the ability to do it (Xunzi 23). The Qur'an says this was given with the soul. And whoever makes the soul pure succeeds (91:9).
Xunzi says goodness is made by deliberate effort, through teachers and the rites the sages made. It does not come from human nature (Xunzi 23).
Rebuttal
Islam says the standard comes from the One who made human nature (30:30). The Qur'an asks, "Should He not know,- He that created?" (67:14). Xunzi says the sages had the same nature as everyone else (Xunzi 23). He roots the rites in Heaven and earth, the ancestors, and rulers and teachers (Xunzi 19). But the sages still made them, and what people made, other people may change.
The Islamic perspective
Every child is born pure, on the fitra: a nature made to know its Lord, guilty of no one else's sin. The soul has been shown its wrong and its right, and both paths are open. Upbringing can cover the fitra, and God's (﷾) message uncovers it. The Qur'an asks to be weighed with care, and its Messenger (ﷺ) was sent to all people.
The Prophet (ﷺ) said every child is born on the fitra, the natural faith. It is the parents who make the child a Jew, a Christian or a Magian (a Zoroastrian).
The Qur'an calls the fitra the pattern on which God (﷾) made mankind, and joins it to the true faith.
The Qur'an says God (﷾) showed the soul what is wrong for it and what is right. Whoever makes it pure succeeds, and whoever corrupts it fails.
The Qur'an names real human weaknesses, such as impatience. And it says those who are devoted to prayer are not ruled by them.
No child is born guilty of another's sin; no bearer of burdens bears the burden of another.
Islam is a complete way of life, and the Qur'an asks to be considered with care. Its Messenger (ﷺ), the last of the prophets, was sent to all people.