John Stuart Mill,
Essays on some unsettled Questions of Political Economy
“ The gross profit of a country is the actual amount of necessaries, conveniences, and luxuries, which are divided among its capitalists: but whether this be large or small, the rate of profit may be just the same. The rate of profit is the proportion which the profit bears to the capital; which the surplus produce after replacing the outlay, bears to the outlay. In short, if we compare the price paid for labour and tools with what that labour and those tools will produce, from this ratio we may calculate the rate of profit. ”
