24. Economic Quantities are, as we have seen, of three distinct species, typified by Money, Labour, and Credit.

Now any of these Quantities may be used in two different ways. The proprietor may use it for his own use or enjoyment: or he may employ it so as to produce a Profit: that is he may trade with it. When any Economic Quantity is traded with; or used so as to produce a Profit, or as it is termed in Economics, employed productively, it is termed Capital.

Stephens in his Thesaurus defines Capital thus - "Caput unde fructus et reditus manat - Capital the source whence any Profit or Revenue flows."

So says Senior - "Economists are agreed that whatever gives a Profit is properly termed Capital."

So M. de Fontenay says - "Wherever there is a Revenue you perceive Capital."

The definition of Capital, therefore, which we adopt is this -