As told by Richard Davies of The New York Times in his article “The Fiction That Makes the World Go Round“, he explored the “evolving paradox” of money as explained by Jacob Goldstein in his book “Money”. Goldstein explains that money is “unalterably social”. In relation to the leader of the Mongol Empire, Kublai Khan, his “treasure exchange vouchers”, similar to paper money, were a form of currency that was a “pure abstraction” and “backed by nothing”. Money didn’t circulate through their economy unless everyone agreed that it would.