I am aware that ideas of good and evil are connected to socially constructs of moral values. Also, it is often bound with ideas about cosmic forces or battles. In Christianity, there was the question of evil as the absence of good. This was to be compared with the idea of good and evil as opposites. To what extent are they equal?
So much comes down to framing of opposites and divisions, ranging from ideas of cosmic battles between good and evil, and systems like Taoism, in understanding perspectives of duality. Are opposites to be regarded as metaphysical forces, or qualia, or aspects of human thinking? How may the human aspect of thinking of opposites and duality be understood?
To what extent are good and evil opposites completely or dual aspects of nature? Is ‘evil’ a necessity for understanding ‘goodness’? To what extent does religious thinking enhance or complicate the understanding of the duality of good and evil, as principles and as aspects of values, especially moral values?
It’s worth knowing that Augustine —probably the most influential Christian behind Jesus himself and the Apostle Paul — was originally a Manichee. This was a cult around the Persian prophet Mani, who taught a radical dualism and just such a ‘cosmic battle between good and evil’. But when Augustine converted to Christianity, he completely changed his view. He adopted the principle of ‘evil as the privation of the Good’. In this understanding, evil has no real, positive existence, but is a lack or deficiency. It can be compared to a shadow, which is the absence of light, or a hole, which is the absence of matter. But these are the kinds of things which can’t exist in their own right (causa sui).
To modern ears, it sounds a harsh idea, as there are so many obvious evils in the world (although in my view, those that are the work of humans are the worst). But still, there are natural calamities, epidemics and catastrophes, which cause untold suffering and death, and not only for humans but for all living creatures. So rationalising this in terms of ‘the absence of good’ is challenging, or downright impossible if we accept that the natural world is all that there is. But this gets into the whole issue of ‘the problem of evil’ and theodicy, if you view it in religious terms. If not, then evil and good are viewed as human constructs or social standards, and the task becomes trying to ameliorate or prevent evil and foster as much good as possible through any means at our disposal.