The Wealth of Nations by Part 5 Chapter 2 Page 101

land; stock employs labour. A tax which tended to drive away stock from any particular country would so far tend to dry up every source of revenue both to the sovereign and to the society. Not only the profits of stock, but the rent of land and the wages of labour would necessarily be more or less diminished by its removal.

The nations, accordingly, who have attempted to tax the revenue arising from stock, instead of any severe inquisition of this kind, have been obliged to content themselves with some very loose, and, therefore, more or less arbitrary, estimation. The extreme inequality and uncertainty of a tax assessed in this manner can be compensated only by its extreme moderation, in consequence of which every man finds himself rated so very much below his real revenue that he gives himself little disturbance though