“Where there is good, there must be evil.” – Lu Wang, 13th century Chinese metaphysician.
In summing up the place of good and evil in a personal philosophical program, the following points are worth emphasis.
You will have to choose an understanding of the words ‘good’ and ‘evil’ that is comprehensive enough to encompass their full meaning; an error in definition may have later consequences. My definition of ‘good’ is that which contributes to the happiness, well-being, longevity, pleasure, or knowledge of oneself and others or at least does not diminish these for others; or which promotes existing non-human reality in the universe . Notice that omitting the latter meaning neglects the value of other living things. Evil then is the opposite.
Goods and evils can be classified as I have done in Table 1 in the Appendix, but the reader may have other thoughts, and the exercise of writing them down is likely to be helpful. Goods can be intrinsic, that is, good in themselves; or instrumental, that is valuable as means to other goods. They can also be internal to the individual and/or external, that is, outside the individual or shared. Intrinsic and internal goods are likely to be more vital to personal meaning and fulfillment. Goods can be ranked, albeit inexactly, but the summum bonum or highest good for most of us is likely to be the dual hope of happiness and meaning.
Evil can be natural or due to free agency; the latter being caused by accident or human imperfections of immaturity, error (especially mistaken certainty), weakness, selfishness (especially self-aggrandizement), and malice. Therefore the twin goals of self-perfection and humility are potent means to limit evil.
Humanity tends to view the universe as the stage for a conflict between Good and Evil, and this mythology has great power in our lives. Varied philosophical sources tell us the best way to defeat evil and separate oneself from it is to be a force for good; that is, good will – the commitment to do good – is the means to both defeat evil and transcend it. Traditionally the ‘saint’ and the ‘hero’ are the two apex manifestations of the self-perfection, humility, sacrifice, and selflessness that allow humans to side with goodness in the universe, and achieve apotheosis.