There must be a balance in good and evil. Just like the balance between day and night, there will be one in our mind and soul. For example, if the world had only ‘good’, then what is left to compare that ‘good’ to? If there is no comparison, then how are we certain that ‘good’ is ‘good’? Also, even if the society is ‘good’, there is always the ‘bad’ in people’s mind and souls. Examples are ‘greed’, ‘jealousy’, ‘lust’, ‘envy’, ‘heresy’, ‘hatred’, ‘gluttony’. There is no such thing as a throughly ‘good’ society, nor a throughly bad society. There is no such thing as perfect, as things can become better or worse the next second. If the world only contained ‘bad’, then why do they continue? Surely, if everyone’s soul contained ‘bad’, wouldn’t they start grabbing, killing, murdering, stealing, and seeking revenge? People would kill each other continuously and then the society would collapse because of the chaos. Why doesn’t it collapse then? It is because there are people who are weaker and those who are stronger will take advantage. The weaker ones cannot do anything and therefore can only hope and wait that they would stop. ‘Hope’ is a factor in ‘good’, and now we can see no matter how ‘good’ or ‘bad’ the society could be, there is always a balance. Just like Yin and Yang concept, ‘good’ and ‘bad’ are interdependent in the natural world and they give rise to each other in turn. Opposites only exist in relation to each other. If one vanishes, the balance would be lost. There are opposites that are interdependent like female and male(female were ‘Yin’, male were ‘Yang’), cold and hot, fire and water, earth and air, dark and light.
This picture here shows Yin and Yang. Yin, or 阴, meaning ‘dark’ or ‘shadow’ in Mandarin Chinese, represented on the diagram as the black twirl. The surface meaning of Yin represents nighttime, with the white circle illustrating the Moon. Its deeper meaning is that it represents the ‘dark force’ or ‘evil spirit’ in the society or in ones soul. Yang, or 阳, meaning ‘light’ or ‘joyful’ in Mandarin Chinese, represented on the diagram as the white twirl. The surface meaning of Yang represents daytime, with the black circle illustrating the Sun. Its deeper meaning is that it represents the ‘light force’ or ‘good spirit’ in the society or in ones soul.