John-Baptiste Say, *Treatise on Political Economy; or the 
Production, Distribution, and Consumption of Wealth,* 1821, Chapter XV:

"It is common to hear adventurers in the different channels of industry 
assert, that their difficulty lies not in the production, but in the 
disposal of commodities; that produce would always be abundant, if there 
were but a ready demand, or vent. When the vent for their commodities 
is slow, difficult, and productive of little advantage, they pronounce 
money to be scarce; the grand object of their desire is, a consumption 
brisk enough to quicken sales and keep up prices...A man, who applies 
his labour to the investing of objects with value by the creation of 
utility of some sort, cannot expect that the value to be appreciated and 
paid for, unless where other men have the means of purchasing it. Now, 
of what do those means consist? Of other values, of other products, 
likewise the fruit of industry, capital and land. Which leads us to a 
conclusion, that may at first sight appear paradoxical; vis. that it is 
production which opens a demand for products...

"Wherefore, it is products that you want, and not money. The silver 
coin you will have received on the sale of your own products, and given 
in the purchase of those of other people, will the next moment execute 
the same office between other contracting parties, and so from one to 
another to infinity; just as a public vehicle successively transports 
objects one after another. If you cannot find a ready sale for your 
commodity, will you say, it is merely for want of a vehicle to transport 
it? For after all, money is but the agent of the transfer of values. 
Its whole utility has consisted in conveying to your hands the value of 
the commodities, which your customer has sold, for the purpose of buying 
again from you; and the very next purchase you make, it will again 
convey to a third person the value of the products you have sold to 
others. So that you will have bought, and everybody must buy, the 
objects of want or desire, each with the value of his respective 
products transformed into money for the moment only. Otherwise, how 
could it be possible, that there should now be bought and sold in France 
five or six times as many commodities, as in the miserable reign of 
Charles VI? Is it not obvious, that five or six times as many 
commodities must have been produced, and that they must have served to 
purchase one the other?"

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