It's simply a medium that makes bartering easier. Don't think a piece of paper is what makes people get up everyday and go to work because it's not. Everyone would still be slaving away if money didn't exist.
It's only slaving when the currency is controlled by a ruling authority. It's not slaving for me to trade you two hours of work for a pair of shoes that you made. It's slaving for me to have to pay someone a currency that they created just to exist in this country.