(c) The third condition of a recognized Science is, that the logical processes appropriate to its class of facts have been already carefully applied to them and a certain number of "exact definitions and sound principles" have been already "educed from and applied to" them. We do not hesitate a moment to claim, that this condition also is fairly and fully met by Political Economy, and that this is a "Science" under the definition from every point of view, and particularly from this third point of view; and a few examples will now be given as a specimen merely of the logical work already achieved in Economics. First, Induction more or less busy for two thousand years has given at last an exact and acceptable definition of the Science, and impliedly an exact description of the class of facts with which it is conversant, namely, the Science of Sales, or what is exactly equivalent, the Science of Value; and Deduction at all points along this slow road has helped to correct and to broaden successive imperfect inductions, which an inquisitive and tentative and cautious spirit—the mainspring of Constructive Science—has instituted from time to time.
Second, precisely the same processes often repeated have ascertained beyond question, that there are only three classes of Valuables and the exact differences between them, and that, consequently, only six cases of Value are possible to happen.
Third, so many nations at different times in all ages have lowered the standard of their Money under a misapprehension of its nature and in a vain hope of profit, and a general scale of rising prices following each attempt of this kind having been several times observed and no instance to the contrary, Economists came by Induction to assert the proposition, that falling Moneys cause rising Prices; the proposition stood secure on inductive grounds alone; but so soon as a perfect definition of Money, namely, a Measure of Services, had at last been reached both inductively and deductively, it became at once a safe Deduction from the definition, that rising Prices must succeed a falling Measure. Thus assurance became doubly sure.
Fourth, Introspection gives each buyer and seller such firm possession of his own motive in buying and selling, that he naturally and inductively concludes on the ground that men are substantially alike, that the motive is similar in the party of the other part; each further step of experience in traffic assures him of this beyond a doubt,—each wants to get and does get something from the other of more consequence to him than what he gives; every attempted deviation from rectitude in trade so far forth throws the trader out from opportunity to trade; opportunity to trade is nothing in the world but a market; a market is nothing in the world but men with products in their hands, desiring to buy other products with these; the more men anywhere with the more products in their hands of all sorts to buy with, the better market everywhere for other men (the more the better) with other products of all kinds to buy with; all the appropriate logical processes in action and reaction, all the commercial experience of all men everywhere, and all the true statistics of traffic ever gathered, do but assure the inductive assent to one of the best and broadest of all the Generalizations in Economics, namely this: A market for products is products in market.
(d) Are the definitions and principles already logically educed from and applied to the great class of Valuables orderly arranged in "a body"? This is the only inquiry that remains, in order to determine whether Political Economy is already a "Science" in the strictest sense of that term. It is admitted, that a jumble of even just definitions and principles do not constitute a science, but only these when placed in a just order and interdependence. A "body" implies an organic arrangement of parts. It has been well said of the human body, that all its parts are reciprocally means and ends; the same may be said of every living organic body, whether vegetable or animal; and the same may be said in the way of analogy of every developed and recognized Science. All the definitions and propositions and illustrations in any science should be so arranged, as to show the mutual relations and reciprocal dependence of all the parts, and as to display the whole in harmony and symmetry.
It is as certain as anything in the future can be in science, that new principles will be discovered in Economics as Time and Inquiry go on, and that these will find their place little by little in a fuller and more rounded "body" than is at present possible; while it is also as certain as anything in the future of science can be, that the Outline of economics is already perfectly drawn, that the great class of Valuables will never be enlarged nor be better described, that the category of Commodities, Services, Credits, is completed for all time, and that the analysis of each act of trade into two Desires and two Efforts and two Estimates and two Renderings and two Satisfactions will never yield additional elements. Political Economy is already a body of exact definitions and sound principles educed from and applied to a single class of facts. This body will indeed be enlarged by a future and finer scientific construction, the arrangement and interdependence of its parts will be better exhibited, the form and filling up of the Science within the outline already determined is sure to become more compact, more robust, and more beautiful, as the decades and centuries go by; while, as in the human body throughout all the changes of its growth and mature life, that future body of economic science in all its stages towards perfection will be but the continuation and fuller development of the present "body" of Political Economy.
CHAPTER II.
MATERIAL COMMODITIES.
Valuables fall naturally and exactly into three classes, Commodities, Services, and Credits. The reasons are obvious at first glance, why articles falling in the first class occupied the thoughts and the efforts of men almost exclusively for the first thousand years of recorded history. Commodities appealed to the senses of men: they are visible, tangible, weighable. Some form of personal slavery existed everywhere, and largely withdrew attention from personal services bought and sold; and there was not apparently sufficient personal confidence between man and man in the earlier ages to allow much development of credits, whose ground is personal trust and whose sphere is future time. Commodities, on the other hand, fitted by the efforts of some men to satisfy the immediate wants of other men, all ready for delivery, to be exchanged against other commodities similarly fitted and at hand, took the field apparently in the earliest ages of recorded Time, gradually became very large in volume, opened new routes of travel and transportation, and served to connect in a rough and ready way neighboring tribes and even neighboring nations.