Evil is the root of all money

I was reading this fantastic paper by Nobuhiro Kiyotaki ,London School of Economics and John Moore Edinburgh University and London School of Economics. Their theory tries to answer the question "Why we do have money?". The essence of the argument is that we need money simply because we do not trust each other. In an ideal world, I would say get the service of someone (e.g doctor) and promise him to pay back by something I do when he needs it. But the doctor does not trust me, so I pay him with rupee notes. A money note is essentially a promise by the central bank. So if I pay the doctor 100 Rs, the doctor essentially has got a promise that when he needs something he can trade this 100Rs to get the service/commodity. A central bank is more credible entity for a doctor than me. This argument applies to everyone. A pretty interesting read !!