The immense importance of securing _first_ a clear and correct Definition of "Value," which is the foundation-word and the circumference-word of Political Economy, and _then_ of using that term and all other scientific terms in the Science in their defined senses only, will certainly be appreciated by those who have wandered in the wide wilderness of the discussions on the undefinable word, "Wealth," and especially by those who have reflected most upon the vast and illimitable significance of economic Exchanges on the welfare of mankind. Associate Justice Miller of the Supreme Court of the United States, not an Economist in the technical sense, referred in 1888, in words that are worth remembering, to "_the philosophical maxim of modern times, that of all the agencies of civilization and progress of the human race commerce is the most efficient_." In August of that year John Sherman of Ohio, a man far enough from being a technical Economist, said in the Senate of the United States, that "_it is almost a crime against civilization_" to maintain commercial barriers between Canada and the United States. There were tokens a plenty in the year of Grace just referred to, that the Science of Value in all the lands of the civilized world, and particularly in the United States, was drawing to itself a new and more popular esteem. It was seen more clearly and felt more deeply than ever before, that this science has a weighty word for every man and woman and child in the world; that there are certain Rights in every one inherent and inalienable to buy and sell for his own advantage; that most if not all of the Governments, under the lead of comparatively few selfish and powerful men, were infringing upon these Rights, and robbing under the forms of Law the masses of their citizens to immense amounts for the special benefit of these very men; that the only sure defences of the people against these abuses of all kinds were in the maintenance and diffusion of the scientific and consequently disinterested principles and maxims of a sound Political Economy; that such a science was only friendly to the broadest rights, to universal gains, to illimitable increase in human comforts and powers, to international fellowship, to peace on earth and good-will among men; that, accordingly, a science of such scope and tendencies must be encouraged and cultivated and improved; that what had been crude in it, and narrow, and merely national, must be sloughed off; that the English and insular and special speculations of a century ago, which regarded "Wealth" as consisting of material things only, excepting however considerable portions of Adam Smith's immortal book, were antiquated and unusable; that the Science had really moved into a broader and still a well-circumscribed field, new and more permanent foundations were being laid, and fresh contributions from all countries should be welcomed; and that the time had fully come, when