Although the inductive process is a common highway of thought in all stages of intellectual growth from childhood to maturity, certain parts of the road are much more frequently traveled in childhood, and still others in youth and maturity. It is the work of pedagogy to adapt its materials to these changing phases of soul life in children. In the analysis of the inductive and deductive processes we desire to come at the solution of this problem.

Considered as a whole, there is a simple phase of the inductive process which is best explained by the terms absorption and reflection. It appears in the study of simple as well as of complex objects, and indicates clearly the fundamental rhythm of the mind in acquiring and elaborating its knowledge. This action of the mind is a shuttle-like movement, a constant running back and forth between two extremes, absorption and reflection. We will test this statement upon examples. When we are in the mood for learning let some new object, a sawmill, attract the attention. A quick general glance at the place and its surroundings tells us what it is. Now trace the operation of the mill as it draws up the logs singly from the rafts lying on the margin of the river and converts them into lumber. You observe first how the logs are carried up an inclined slide by means of an endless chain with hooks, into the mill. You examine this first piece of machinery and notice its mode of action. As the logs enter the upper story of the mill, they are thrown by heavy levers to either side and roll down toward the saws. Here is another piece of machinery in its proper place. Having been stripped of the loose pieces of bark, the logs are grasped by another set of iron hands, lifted firmly to the carriage and passed to the circular or band-saw, which takes off the side slabs and squares them for the gang-saw. The squared logs are then carried along over rollers and collected before the gang-saws. From two to four of them are clasped firmly together and then forced up against the teeth of the parallel group of saws, issuing from them as a batch of lumber. The boards are then passed on to a set of men at small circular saws, by whom they are sorted and the edges trimmed, while still others with trucks carry them to the yard for stacking.

Take note of the operation of the mind as it passes from one part of the machinery to another. Each part is first examined by itself to get its construction and method. Then its relation to what precedes and what follows is noted. Finally, in review you survey the whole process in its successive stages and understand each part and its relation to the whole and to the purpose of the mill. We might call this an analysis and synthesis of the process of making lumber, or in other words absorption and reflection. In the observation of such a complex piece of machinery as a large mill the mind swings back and forth many times between absorption in the study of parts and reflection upon their relation to each other.

Having examined the mill in detail and grasped its parts as a connected whole, the next step is to observe its relation to the river, to the rafts and rafting-boats, and further back to the pineries and logging-camps up the river. (Northern Minnesota and Wisconsin.) The occupations and sights along the Upper Mississippi and its head-waters, the pineries, and even the spring floods, are intimately connected, causally, with the saw-mills and lumber yards lower down. Or going in the opposite direction from the saw-mill, we follow the lumber till it is used in the various forms of construction. Some of it enters the planing-mills and is converted into moldings, finishing lumber, sashes, blinds, etc. In all forms it is loaded upon the cars, and shipped westward to be used in the construction of houses and bridges.

Before we get through with the line of thought engendered by observing the saw-mill, we have canvassed the whole lumber industry from the pineries to the plans of architects and builders in the actual work of construction. Not only has there been this progress of the mind from one object or machine to another of a series connected by cause and effect, but there has been also a constant tendency to pass from the individual machines of which the series is composed to the classes of which these objects are typical. A circular-saw or a gang-saw is each typical of a class of saws. The same is true of each part of the machinery, as well as of the saw-mill or planing-mill considered as a whole. Each of these objects, whether simple or complex, suggests others similar which we have observed or seen represented in pictures. Each part of the machinery in turn becomes the center of a set of comparisons leading from the concrete object in question to the general notion of the class to which it belongs. For example, the steam engine in a mill is typical of all stationary engines used for driving machinery. But the parts of the engine are also typical of similar parts in other engines and machines, as the drive-wheel, cylinder, boiler, etc.

In all these cases we become absorbed in one thing for a while, only to recover ourselves and to reflect upon the thing in its wider relations, either tracing out connections of cause and effect, as in a series of machines, or passing from the single example to the class of which it is typical. Absorption and reflection! The mind swings back and forth like a pendulum between these two operations. Herbart, who closely defined this process, called it the mental act of breathing, because of the constancy of its movement. As regularly as the air is drawn into the lungs and again expelled, so regularly does the mind lose itself in its absorption with objects only to recover itself and reflect upon them.

In the inspection of a large printing press in one of our newspaper publishing-houses we meet with a similar experience. The attention becomes centered upon the press for a close analysis and synthesis of its parts. The cogs, wheels, rollers, inking-plate, the chases for the type, the application of the power, the springs and levers, each part receives a close inspection, and the secret of its connection with other parts is sought for. There is a vigorous effort not only to understand each part but also the connection of the whole. The shuttle-like movement of the mind back and forth between the parts, absorbed for a moment, reflecting for a moment, continues until the complex mechanism is understood. When this process has been satisfactorily completed, we are ready to turn our minds again to the other objects and rooms of the printing establishment. The work of the compositors, setting up different kinds of type, the proof-reading, the editorial work, the reporters, all come in for a share of attention. The reporters lead us to the great world outside whose happenings are brought here for publication. On the other hand, following the distribution of papers as they issue from the press, we think of news-boys, news-stands, mail-service, railroads, and postoffices. But the inspection of a printing press also leads the thoughts in other directions and suggests other presses, great and small, in other times and places, other printing establishments, until the whole business of printing and publishing books and papers springs into the thought.

If we desire to understand clearly the business of publishing a newspaper, we must enter into an observation of the parts of the process from the collection of its news to its distribution by the mails and carriers. Besides noting these parts we must observe their causal connection with each other and the rôle that each plays in the economy of the whole. The causal series thus clearly outlined produces insight into an occupation, while every typical machine or appliance is one of a cross series intercepting the original series. The acquisition and assimilation of knowledge in different subjects will be found to exhibit the mental states of absorption and reflection as just illustrated. Observe the manner in which we study a poem. It is first read and interpreted sentence by sentence, glancing from verse to verse to get the connections. When the whole piece has been read and understood in its parts and connections, the suggested lines of thought are taken up and followed out in their wider applications. Take for example the "Burial of Moses," and in the proper analysis and study of the poem, such a process of absorption and reflection is observable. In tracing the biography of John Quincy Adams or of Alexander Hamilton, the facts of personal experience and action first absorb the attention from step to step in the study of his life. But reflection on the bearings of these personal events, upon contemporaries, and upon public affairs is noticed all along. The same mental process is observed in studying a battle in history, a sentence in grammar, a squirrel in natural history, or a picture in art.

The effect of such mental absorption and reflection is to build up concepts. Series of causally related parts are also formed, but each series in the end becomes a more complete complex concept; that is, a representative of many similar series. The inspection of one printing establishment suggests others which are brought into comparison till the general notion, publishing-house, is more clearly conceived. The same is true in the lumber trade. The concept lumber-business is not confined to Minneapolis or Chicago, but is common to the great lake region, Maine, Washington, Norway, and other countries. Concepts become more varied and complex with the advance of studies, and there is scarcely anything we learn by observation or reflection that does not ultimately illustrate and build up our concepts. The observation of even the miscellaneous objects in a large city leads to a variety of concepts, and in the end, by comparison, to the general notion, city.

How strong the concept-creating tendency of all experience and thought is, can be seen in the words of language. The processes of thought become petrified in language. All progress in knowledge and acquisition of new ideas is reflected in language by an increase of words. But an examination of words in common use will show that they are nearly all the names of concepts. Proper names are the principal exception. Every common noun, verb, adjective, adverb, and preposition is the name of a concept; for example, horse, beauty, to steal, running, over, early, yellow, grape, ocean, etc. To understand these concepts there must be somewhere a progress from the individual to the abstract, an induction from particulars to a general concept.