body of knowledge,—­have been the work of Mill.  In Ricardo’s great work, the fundamental doctrines of production, distribution, and exchange have been laid down, but for the most part in mere outline; so much so, that superficial students are in general wholly unable to connect his statement of principles with the facts, as we find them, of industrial life.  Hence we have innumerable “refutations of Ricardo,”—­almost invariably refutations of the writers’ own misconceptions.  In Mill’s exposition, the connection between principles and facts becomes clear and intelligible.  The conditions and modes of action are exhibited by which human wants and desires—­the motive powers of industry—­come to issue in the actual phenomena of wealth, and political economy becomes a system of doctrines susceptible of direct application to human affairs.  As an example, I may refer to Mill’s development of Ricardo’s doctrine of foreign trade.  In Ricardo’s pages, the fundamental principles of that department of exchange are indeed laid down with a master’s hand; but for the majority of readers they have little relation to the actual commerce of the world.  Turn to Mill, and all becomes clear.  Principles of the most abstract kind are translated into concrete language, and brought to explain familiar facts; and this result is achieved, not simply or chiefly by virtue of mere lucidity of exposition, but through the discovery and exhibition of modifying conditions and links in the chain of causes overlooked by Ricardo.  It was in his “Essays on Unsettled Questions in Political Economy” that his views upon this subject were first given to the world,—­a work of which M. Cherbuliez of Geneva speaks as “un travail le plus important et le plus original dont la science economique se soit enrichie depuis une vingtaine d’annees.”

On some points, however, and these points of supreme importance, the contributions of Mill to economic science are very much more than developments—­even though we understand that term in its largest sense—­of any previous writer.  No one can have studied political economy in the works of its earlier cultivators without being struck with the dreariness of the outlook which, in the main, it discloses for the human race.  It seems to have been Ricardo’s deliberate opinion, that a substantial improvement in the condition of the mass of mankind was impossible.  He considered it as the normal state of things that wages should be at the minimum requisite to support the laborer in physical health and strength, and to enable him to bring up a family large enough to supply the wants of the labor-market.  A temporary improvement indeed, as the consequence of expanding commerce and growing capital, he saw that there might be; but he held that the force of the principle of population was always powerful enough so to augment the supply of labor as to bring wages ever again down to the minimum point.  So completely had this belief become a fixed idea in Ricardo’s mind, that