0)1 the Use of Dejinitions. 2']1 be wanted : and there can be little doubt that then we shall have no great difficulty in laying our hands on such terms. But if at first and at once, before our classification is begun, we define terms, Ave deduce laws, we assert these to be univer- sally true, we cast about in each case for modes of evading the discrepancy between the rules which we promulgate and those which the covirse of human affairs follows, what are we to expect? From what has preceded, the answer is clear. We are not to expect to attain any knowledge which will be applicable to facts, except the progress of this science should follow rules and conditions altogether different from those which any other progressive science has ever yet followed. What is this science ? the science which thus attempts to trace the laws which determine the the polity, the economical structure, the wealth of ?2ations? Is it Political Economy? Probably not : for the most celebrated teachers of that science speak with scorn of the prospect of collecting their principles by this slow and laborious process of observation and com- parison. Their truths are to flow from the inexhaustible foun- tain of definition ivithont previous knoiioledge and classifica- tion of facts. So that Political Economy must be a branch of metaphysics, in the same sense in which Bacon truly asserts that Geometry is so. But the science which treats of the wealth of nations, that is of the wealth which they actually have, and not of that which, according to certain suppositions, they would have, is still a province of human knowledge worthy some of our notice. And in this, a science of observation, we must expect to find the same rules regulating our progress which, as we have seen, have hitherto governed the progress of other sciences of observation. We must expect that w^e shall be able to obtain definitions worth putting into words, only so far as we succeed in classifying facts, and discovering some traces of law. For instance, if we compare the payments made by the occupiers of the soil to the owners of it, in different countries, we may call them all by the common term re7it^ because such an ap- pHcation of the word appears to be consistent with common usage. But if we are rash enough to give a definition of the amount of rent, depending upon some conjectural hypothesis or special accident, as for instance, on the possibility of Vol. II. No. 5. M m
