very thought provoking. everything has an exact opposite. what about the opposite is actually a lack of the first thing?
light is light but dark exists because there is a lack of light, so much so that it is dark. evil exists because good is lacking. not so much of opposites, rather a conservation of matters & concepts. yin & yang. cold exists because there is no heat. switch off your light & your monitor in the middle of the night & u will say that it's dark. what about closing your eyes? it's dark as well! if dark is opposite of light, it's quantifiable. meaning, u can measure darkness as much as u can measure light. but u can't. just like cold & heat.
my 2 cents.