In this mode of conducting inquiry, there is, no doubt, a chance of falling into errors of an opposite kind to those which arise from a tendency to simplification. Certain appearances, which are merely co-existent and incidental, may be mistaken for causes; and a theory formed upon this mistake will unite the double disadvantage of being both complex and incorrect. Adam Smith has occasionally fallen into this error, and drawn inferences from actual appearances, not warranted by general principles. From the low price of wheat, for instance, during the first half of the last century, he seems to have inferred that wheat is generally cheaper in rich than in poor countries; and from the small quantity of corn actually imported during that period, even in the scarcest years, he has inferred generally, that the quantity imported can never be such as to interfere with the home growth. The actual state of things at a subsequent period, and particularly during the last twenty-five years, has sufficiently shewn that these appearances were merely incidental; that a very rich country may have its corn extremely dear, as we should naturally expect; and that importation in England has amounted to more than 110 instead of 1517[1] part of the crop raised in the country; and may, therefore, to a considerable extent, interfere with the home growth.
Aware, however, of my liability to this error on the one side, and to the error of not referring sufficiently to experience on the other, my aim will be to pursue, as far as I am able, a just mean between the two extremes, and to approach, as near as I can, to the great object of my research—the truth.
Many of the doctrines of Adam Smith, which had been considered as settled, have lately been called in question by writers entitled to great attention; but they have often failed, as it appears to me, to make good their objections; and in all such cases I have
- ↑ Wealth of Nations, B. IV. c. ii. p. 190. 6th edit.
