Actually, you missed something important, Ethan. Semantic opposition is a huge deal as something that has to be accounted for in brain computation. The way we do this is to notice a) oppositions are fairly rare (sparse semantically) and b) indicative of things that we monitor in everything said in natural language to each other. 'What he said was good not bad', 'where he is is up north, not down south'. These are dualities. But as you point out, the earth is quartite (N,E,S,W). We don't naturally discriminate and classify this way. We discriminate and classify in opposites. So, I would suggest, we will never give up our definitions of north and south because, as opposites on where something can be found is going to stick. An interesting question for a survey of people is to see if they think "latitude" and "longitude" are opposites. My bet is that people who know what they are, won't. People who are not thinking about what they actually are, will. Just like the probability, by how the brain computes, is that if I ask someone if "This sentence is a lie" is true, they will say yes, until they think harder and their brain explodes. Opposites are interesting and stick around as linguistic universals.