If the value of foreign commodities imported is to be estimated by the quantity of labour worked up in the commodities sent out to purchase them, then it is quite true that, whatever may be the returns, their value is unsusceptible of increase. But if the value of foreign commodities imported be estimated in the way in which they had ever been estimated before, that is, either in the money, in the labour, or in the mass of commodities which they would command when brought home, then there cannot be the least doubt that the _immediate_ effect of a prosperous venture which gives great profits to the merchants concerned would be to increase the amount of value in the country. The value of the returns compared with the value of the outgoings would, in this particular trade, be greater than usual; and it is quite certain, that this increase of value in one quarter would not necessarily be counterbalanced by a decrease of value in any other. Practically, indeed, nothing is more usual than a simultaneous rise in the value of the great mass of commodities from a prosperous trade, whether this value be estimated in money or in labour. It must be allowed, then, that Mr. Ricardo has been very far from cautious in the definition and application of his terms, in treating of some of the most fundamental principles of political economy; and I have very little doubt, as I have stated elsewhere, that this is one of the reasons why many of the readers of his work have found great difficulty in understanding it. When old and very familiar terms are used in a new sense, it is scarcely possible for the writer to be always consistent in their application, and extremely difficult to the reader always to be aware of the sense meant to be affixed to them. CHAPTER VI. ON THE DEFINITION AND APPLICATION OF TERMS BY MR. MILL, IN HIS “ELEMENTS OF POLITICAL ECONOMY.” Mr. Mill, in his _Elements of Political Economy_, professedly lays no claim to discovery. His main object seems to have been to give the substance of Mr. Ricardo’s work in a more concentrated form, and with a better arrangement; and this object he has accomplished. In the definition and application of his terms he nearly follows Mr. Ricardo; but it may be useful to notice a few cases, where he has either made the errors of Mr. Ricardo’s definitions more prominent, or has altered without improving them.