I've read Plato.
I refer to Plato's Symposium, specifically what he philosophized regarding soulmates, in my novel "Julianne's Wish".
It comes across as rather romantic for my novel.
But the guy's thinking is actually weird.
He claims that mankind used to have two heard, four arms, four legs, and both male and female genitalia. And the gods fearing our strength cut us in half.
That's why we now only have one head, two arms, two legs, and only one sex.
Now to hook up with our soul mate.