Adam Smith - The Wealth of Nations

In the most improved societies, however, there are always a few commodities of which the price resolves itself into two parts only, the wages of labour, and the profits of stock; and a still smaller number, in which it consists altogether in the wages of labour. In the price of sea-fish, for example, one part pays the labour of the fishermen, and the other the profits of the capital employed in the fishery. Rent very seldom makes any part of it, though it does sometimes, as I shall show hereafter. It is otherwise, at least through the greater part of Europe, in river fisheries. A salmon fishery pays a rent, and rent, though it cannot well be called the rent of land, makes a part of the price of a salmon as well as wages and profit. In some parts of Scotland a few poor people make a trade of gathering, along the sea-shore, those little variegated stones commonly known by the name of Scotch Pebbles. The price which is paid to them by the stone-cutter is altogether the wages of their labour; neither rent nor profit make any part of it.

But the whole price of any commodity must still finally resolve itself into some one or other, or all of those three parts; as whatever part of it remains after paying the rent of the land, and the price of the whole labour employed in raising, manufacturing, and bringing it to market, must necessarily be profit to somebody.

As the price or exchangeable value of every particular commodity, taken separately, resolves itself into some one or other or all of those three parts; so that of all the commodities which compose the whole annual produce of the labour of every country, taken complexly, must resolve itself into the same three parts, and be parcelled out among different inhabitants of the country, either as the wages of their labour, the profits of their stock, or the rent of their land. The whole of what is annually either collected or produced by the labour of every society, or what comes to the same thing, the whole price of it, is in this manner originally distributed among some of its different members. Wages, profit, and rent, are the three original sources of all revenue as well as of all exchangeable value. All other revenue is ultimately derived from some one or other of these.

Whoever derives his revenue from a fund which is his own, must draw it either from his labour, from his stock, or from his land. The revenue derived from labour is called wages. That derived from stock, by the person who manages or employes it, is called profit. That derived from it by the person who does not employ it himself, but lends it to another, is called the interest or the use of money. It is the compensation which the borrower pays to the lender, for the profit which he has an opportunity of making by the use of the money. Part of that profit naturally belongs to the borrower, who runs the risk and takes the trouble of employing it; and part to the lender, who affords him the opportunity of making this profit. The interest of money is always a derivative revenue, which, if it is not paid from the profit which is made by the use of the money, must be paid from some other source of revenue, unless perhaps the borrower is a spendthrift, who contracts a second debt in order to pay the interest of the first. The revenue which proceeds altogether from land, is called rent, and belongs to the landlord. The revenue of the farmer is derived partly from his labour, and partly from his stock. To him, land is only the instrument which enables him to earn the wages of this labour, and to make the profits of this stock. All taxes, and an the revenue which is founded upon them, all salaries, pensions, and annuities of every kind, are ultimately derived from some one or other of those three original sources of revenue, and are paid either immediately or mediately from the wages of labour, the profits of stock, or the rent of land.

When those three different sorts of revenue belong to different persons, they are readily distinguished; but when they belong to the same they are sometimes confounded with one another, at least in common language.

A gentleman who farms a part of his own estate, after paying the expense of cultivation, should gain both the rent of the landlord and the profit of the farmer. He is apt to denominate, however, his whole gain, profit, and thus confounds rent with profit, at least in common language. The greater part of our North American and West Indian planters are in this situation. They farm, the greater part of them, their own estates, and accordingly we seldom hear of the rent of a plantation, but frequently of its profit.

Common farmers seldom employ any overseer to direct the general operations of the farm. They generally, too, work a good deal with their own hands, as ploughmen, harrowers, etc. What remains of the crop after paying the rent, therefore, should not only replace to them their stock employed in cultivation, together with its ordinary profits, but pay them the wages which are due to them, both as labourers and overseers. Whatever remains, however, after paying the rent and keeping up the stock, is called profit. But wages evidently make a part of it. The farmer, by saving these wages, must necessarily gain them. Wages, therefore, are in this case confounded with profit.

An independent manufacturer, who has stock enough both to purchase materials, and to maintain himself till he can carry his work to market, should gain both the wages of a journeyman who works under a master, and the profit which that master makes by the sale of the journeyman's work. His whole gains, however, are commonly called profit, and wages are, in this case too, confounded with profit.

A gardener who cultivates his own garden with his own hands, unites in his own person the three different characters of landlord, farmer, and labourer. His produce, therefore, should pay him the rent of the first, the profit of the second, and the wages of the third. The whole, however, is commonly considered as the earnings of his labour. Both rent and profit are, in this case, confounded with wages.

As in a civilised country there are but few commodities of which the exchangeable value arises from labour only, rent and profit contributing largely to that of the far greater part of them, so the annual produce of its labour will always be sufficient to purchase or command a much greater quantity of labour than what employed in raising, preparing, and bringing that produce to market. If the society were annually to employ all the labour which it can annually purchase, as the quantity of labour would increase greatly every year, so the produce of every succeeding year would be of vastly greater value than that of the foregoing. But there is no country in which the whole annual produce is employed in maintaining the industrious. The idle everywhere consume a great part of it; and according to the different proportions in which it is annually divided between those two different orders of people, its ordinary or average value must either annually increase, or diminish, or continue the same from one year to another.

There is in every society or neighbourhood an ordinary or average rate both of wages and profit in every different employment of labour and stock. This rate is naturally regulated, as I shall show hereafter, partly by the general circumstances of the society, their riches or poverty, their advancing, stationary, or declining condition; and partly by the particular nature of each employment.

There is likewise in every society or neighbourhood an ordinary or average rate of rent, which is regulated too, as I shall show hereafter, partly by the general circumstances of the society or neighbourhood in which the land is situated, and partly by the natural or improved fertility of the land.