Mencius said that human nature is good. I disagree with that.

The petty man is eager to make boasts, yet desires that others should believe in him. He enthusiastically engages in deception, yet wants others to have affection for him. He conducts himself like an animal, yet wants others to think well of him.

Man's nature is evil; goodness is the result of conscious activity.

In antiquity the sage kings recognized that men's nature is bad and that their tendencies were not being corrected and their lawlessness controlled.

When a man sees something desirable, he must reflect on the fact that with time it could come to involve what is detestable. When he sees something that is beneficial, he should reflect that sooner or later it, too, could come to involve harm.

Thus, anybody who follows this nature and gives way its states will be led into quarrels and conflicts, and go against the conventions and rules of society, and will end up a criminal.

Now it is human nature to want to eat to ones fill when hungry, to want to warm up when cold, to want to rest when tired. These all are a part of people's emotional nature.