Political economy has only become a science since it has been confined to the results of inductive investigation.
Jean-Baptiste SayTo the labor of man alone Smith ascribes the power of producing values. This is an error. A more exact analysis demonstrates... that all the values are derived from the operation of labor, or rather from the industry of man, combined with the operation of those agents which nature and capital furnish him.
Jean-Baptiste SayTo a proprietor of a mine, the silver money is a produce with which he buys what he has occasion for. To all those through whose hands this silver afterwards passes, it is only the price of the produce which they themselves have raised by means of their property in land, their capitals, or their industry. In selling them they in the first place exchange them for money, and afterwards they exchange the money for articles of consumption.
Jean-Baptiste Say