The Wealth of Nations by Part 4 Chapter 9 Page 33

species of industry, it would depress another more valuable species of industry. By raising up too hastily a species of industry which only replaces the stock which employs it, together with the ordinary profit, it would depress a species of industry which, over and above replacing that stock with its profit, affords likewise a net produce, a free rent to the landlord. It would depress productive labour, by encouraging too hastily that labour which is altogether barren and unproductive.

In what manner, according to this system, the sum total of the annual produce of the land is distributed among the three classes above mentioned, and in what manner the labour of the unproductive class does no more than replace the value of its own consumption, without increasing in any respect the value of that sum total, is represented by