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._