When millions of people produce goods for each other’s use, they must have some way of notifying each other of their desires. Moreover, people’s desires and preferences are fluctuating, complex and delicate. James Joyce could have filled a fat volume in describing the half-formed inclinations in the mind of a woman setting out on a shopping expedition. No words could completely define her potential desires. Consumers cannot therefore be expected to present shopkeepers with an adequate psychological analysis of their needs. Money comes to their rescue. Their offer to buy certain things at certain prices completely reveals what they have in mind.

Michael Polanyi (1951). The Logic of Liberty, p 139