Sir Hubert Douglas Henderson, Supply and Demand
“ Interest is the price paid simply for the use of capital. But what is capital, and in what does its use consist? What claim has it to be regarded as an independent factor of production? Our very familiarity with the term, our habit of employing it with the rich looseness of every-day life is an obstacle to the clearness of thought, which is again essential. We recognize, most of us, clearly enough that capital, although we reckon it in terms of money, consists, like income, of real things; factories, machinery, materials and the like. ”
