Conversation

Where does the idea of "2 hearts beating as one" originally come from? google turns up a U2 song, and I recall a "one heart and one purse between them" quote from Merchant of Venice. It's right on the edge between a commodity sentiment and something that feels like a quote.
Replying to
Plato? “Every heart sings a song, incomplete, until another heart whispers back”. Tie that to the two halves of a single whole story and you seem to have all the elements.