[sillysally]

This is a great thread to read. I have a hard time believing that opposites actually exist. So we think male and female is opposite but really we aren't, xy is not opposite to xx. The things we see and the way we understand them may appear opposite to us like up and down but we truly don't know the difference. Our perception is mostly based on visual, what we see, we don't know how accurate it is. A man looks different from a woman on the outside, but inside we know he has mammary glands like a woman and an appendix for child bearing, his penis is just an overgrown clit, give a woman enough steroids and she will grow one too.

I think the pairing comes when there is a change in structure of the same thing, not opposite. It's the exact same structure, just arranged differently. Up and down is the same depending on where you are arranged to see it.