"No equal quantity of productive labour or capital employed in manufacture can ever occasion so great a reproduction as if it were employed in agriculture. In these, nature does nothing, man does all, and the reproduction must always be proportioned to the strength of the agents that occasion it. The capital employed in agriculture, therefore, not only puts into motion a greater quantity of productive labour than any equal capital employed in manufacture; but, in proportion, too, to the quantity of productive labour which it employs, it adds a much greater value to the annual value of the land and labour of the country, to the real wealth and revenue of its inhabitants. Of all the ways which a capital can be employed, it is by far the most advantageous to society." This is the starting point of his whole system, and is directly the opposite of that from which starts the modern English politico-economical school that professes to follow in his footsteps, as will now be shown. The passage here given, which really constitutes the base upon which rests the whole structure of Dr. Smith's work, is regarded by Mr. McCulloch as "the most objectionable" one in it, and he expresses great surprise that "so acute and sagacious a reasoner should have maintained a doctrine so manifestly erroneous." "So far indeed," says that gentleman-- "Is it from being true that nature does much for man in agriculture, and nothing for manufactures, that the fact is more nearly the reverse. There are no limits to the bounty of nature in manufactures; but there are limits, and those not very remote, to her bounty in agriculture. The greatest possible amount of capital might be expended in the construction of steam-engines, or of any other sort of machinery, and, after they had been multiplied indefinitely, the last would be as prompt and efficient in producing commodities and saving labour as the first. Such, however, is not the case with the soil. Lands of the first quality are speedily exhausted; and it is impossible to apply capital indefinitely even to the best soils, without obtaining from it a constantly diminishing rate of profit."--_Principles of Political Economy_.