"A coin, like a human being, is the material embodiment of an invisible essence (value, the soul) present also in other coins or human beings. And just as the individual unitary human soul may seem self enclosed, separate from the social process by which it is in fact formed, so the coin may seem to enclose within itself the unitary invisible value that in fact depends entirely on circulation."
Richard Seaford Money and the Early Greek Mind 2004 p.298