Money, they say, does not buy happiness; but having none can make life extraordinarily hard. Whether we have a little or a lot, we are all familiar with how much money matters in our daily lives. But what exactly is money? Is it a commodity that evolved spontaneously from systems of barter? Or is it purely an invention of government, used as a means to pay off tax liability? What difference would the answer make to things like job creation, inflation, and government spending? And how do modern inventions like cryptocurrency fit into a theory of money? The philosophers go on a spending spree with Graham Hubbs from the University of Idaho, editor ofPragmatism, Law, and Language.