[66] The science which in modern days had been called Political Economy is in reality nothing more than the investigation of the phenomena of commercial operations. It has no connexion with political economy, as understood and treated of by the great thinkers of past ages; and as long as it is allowed to pass under the same name, every word written by those thinkers--and chiefly the words of Plato, Xenophon, Cicero, and Bacon--must be either misunderstood or misapplied. The reader must not, therefore, be surprised at the care and insistence with which I have retained the literal and earliest sense of all important terms used in these papers; for a word is usually well made at the time it is first wanted; its youngest meaning has in it the full strength of its youth; subsequent senses are commonly warped or weakened; and as a misused word always is liable to involve an obscured thought, and all careful thinkers, either on this or any other subject, are sure to have used their words accurately, the first condition, in order to be able to avail ourselves of their sayings at all, is a firm definition of terms. The assumption which lies at the root of nearly all erroneous reasoning on political economy--namely, that its object is to accumulate money or exchangeable property--may be shown in few words to be without foundation. For no economist would admit national economy to be legitimate which proposed to itself only the building of a pyramid of gold. He would declare the gold to be wasted, were it to remain in the monumental form, and would say it ought to be employed. But to what end? Either it must be used only to gain more gold, and build a larger pyramid, or to some purpose other than the gaining of gold. And this other purpose, however at first apprehended, will be found to resolve itself finally into the service of man--that is to say, the extension, defence, or comfort of his life. The golden pyramid may perhaps be providently built, perhaps improvidently; but, at all events, the wisdom or folly of the accumulation can only be determined by our having first clearly stated the aim of all economy, namely, the extension of life.