Plato remarks in passing that money is a ‘symbol’ devised for the purpose of facilitating exchange (Politeia II, 371; Jowett translated σύµβоλоν by ‘money-token’). Now such an occasional saying means very little and does not justify the attribution to Plato of any definite view on the nature of money. But it must be observed that his canons of monetary policy—his hostility to the use of gold and silver, for instance, or his idea of a domestic currency that would be useless abroad— actually do agree with the logical consequences of a theory according to which the value of money is on principle independent of the stuff it is made of. In view of this fact it seems to me that we are within our rights if we claim Plato as the first known sponsor of one of the two fundamental theories of money, just as Aristotle may be claimed as the first known sponsor of the other (sec. 5b below). It is highly unlikely, of course, that these theories originated with them, but it is certain that they taught them and that they attached exactly the same meaning to them as did the authors who again took them up from the late Middle Ages on. We may assume this with confidence because those authors display both Platonic and Aristotelian influences clearly enough. In fact, filiation can be strictly proved.
1. Schumpeter, Joseph A. History of Economic Analysis. New York: Oxford UP, 1954. Print. 56.