There is a growing conviction among teachers that we need a closer _articulation_ of studies with one another. The expansion of the school course over new fields of knowledge and the multiplication of studies already discussed compels us to seek for a simplification of the course. A hundred years ago, yes, even fifty years ago, it was thought that the extension of our territory and government to the present limits would be impossible. It was plainly stated that one government could never hold together people so widely separated. Mr. Fiske says: (The Critical Period of Am. Hist., p. 60) "Even with all other conditions favorable, it is doubtful if the American Union could have been preserved to the present time without the railroad. Railroads and telegraphs have made our vast country, both for political and for social purposes, more snug and compact than little Switzerland was in the middle ages or New England a century ago." The analogy between the realm of government and of knowledge is not at all complete but it suggests at least the change which is imperatively called for in education. In education as well as in commerce there must be trunk lines of thought which bring the will as monarch of the mind into close communication with all the resources of knowledge and experience. Indeed in the mind of a child or of an adult there is much stronger necessity for centralization than in the government and commerce of a country. The will should be an undisputed monarch of the whole mental life. It is the one center where all lines of communication meet. London is not so perfect a center for the commerce and finance of England as is the conscious _ego_ (smaller than a needle's point) for all its forms of experience.
Besides the central trunk lines of knowledge in history and natural science there are branches of study which are _tributary_ to them, which serve also as connecting chains between more important subjects. Reading, for instance, is largely a relative study. Not only is the art of reading merely a preparation for a better appreciation of history, geography, arithmetic, etc., but even the subject-matter of reading lessons is now made largely tributary to other studies. The supplementary readers consist exclusively of interesting matter bearing upon geography, history, and natural science. It is a fact that reading is becoming more and more a relative study, and selections are regularly made to bear on other school work. Geography especially serves to establish a network of connections between other kinds of knowledge. It is a very important supplement to history. In fact history cannot dispense with its help. Geography lessons are full of natural science, as with plants, animals, rocks, climate, inventions, machines, and races. Indeed there are few if any school studies which should not be brought into close and important relations to geography. Again the more important historical and scientific branches not only receive valuable aid from the tributary studies but they abundantly supply such aid in return. Language lessons should receive all their subject-matter from history and natural science. While the language lessons are working up such rich and interesting materials for purposes of oral and written language, the more important branches are also illustrated and enriched by the new historical and scientific subjects thus incidentally treated.