have some point of view for judgment. This is furnished by the underlying psychological concept which functions to give direction to our investigation. Qualities are essential only in so far as they meet the needs of the problem in hand. The logical concept to be attained must have that core of meaning which shall make of it an efficient tool in the control of individuals either in action or in thought. Only qualities or characteristics which are thus regarded as essential are abstracted, no matter how many others are

common.

Minneapolis and Chicago may both have good school systems, they may both be lighted by gas, or both by electricity. Possibly the average height of the inhabitants of both cities may be the same, etc. But we all feel at once the irrelevancy of this set of common qualities. Why? Because we have enough of an idea of trade center embodied in our psychological concept to know that these common qualities or characteristics are not within the field of our problem.

But both cities lie within a region that needs to be furnished with supplies and that also needs to get rid of raw materials; both cities have excellent railway communications with various parts of the surrounding country; both cities have water-ways suitable for the transport of goods; both cities are engaged in receiving raw materials, converting them into manufactured articles, and sending them out to other places for consumption; both places serve as centers for the collection and redistribution of various kinds of products. In the process of comparison, we run across many such common characteristics which we instantly feel are relevant to our problem. We focus our attention upon these and hold them in mind.

At the same time there is a process of elimination of the apparently relevant that takes place. We find the waterfall at Minneapolis an important factor in making it a trade center, but there is none at Chicago. We find a

river at Minneapolis, and a great lake at Chicago; water in some form seems very relevant. Perhaps it is essential. We compare with Birmingham, Alabama, and see that this is a great trade center of the South, but an inland city, relying wholly upon railways for its commerce. Now if, through our study of Minneapolis first, we had included in our psychological concept trade center waterfalls, river, and lumber industry; in the process of comparison these elements would have been eliminated as elements which belong in the essential core of meaning. This is the negative aspect of abstraction.

Abstraction proper consists in the selection of those common characteristics and qualities discovered in the process of comparison which are judged to be essential from the point of view of our problem, the withdrawing of these from the tangle of complex details and the holding of them off before the mind for separate consideration.

(4) Generalization.

This does not consist merely in massing together the common, or even the essential common, qualities of all the individuals into one complex,-a sort of composite photograph affair. It does consist in setting up under the control of a single image the abstracted essential qualities as a standard, as a central core of meaning, by which to judge and interpret all the individuals of a group. Under one image are organized a system of meanings which serves as a rule for the determination of all the individuals of a class. The outcome is that this image more adequately symbolizes the appropriate reaction, mental or motor, to all the individuals of the group.

When we have gathered together the characteristics which are essential to a trade center,-that it shall be a place which receives and transmits goods, that it shall have facilities for the conversion of raw materials into manufactured articles, that it shall have suitable means of conveyance by rail or by water from one place to another,

etc., we set up these abstracted qualities, organized into one whole, as a standard, or rule, which we apply to every city to determine whether it is a trade center or not. The act of mentally asserting that this core of meanings does constitute the standard, and that every city that shall be called a trade center must conform to the standard of possessing these characteristics,-this act is generalization. Generalization is, then, a far more constructive and a far more dynamic and purposive process than any sort of mental composite photography.

4. INTERRELATIONS OF THE FORMAL "STEPS."

It should be observed that the "steps" of observation, comparison, abstraction, and generalization are not absolutely separate and distinct. Their arrangement in a definite order is more or less formal, useful for the purpose of description. They overlap and interpenetrate one another in the actual thinking process. But they represent essential movements within the inductive process. The term phases would be a better term to employ than the more popular term "steps." To indicate that we are using the term "steps" in a popular and loose sense only, we have employed quotation marks.

Observation is for the sake of comparison, and comparison may be simultaneous with observation, each exercising a determining influence upon the other; comparison is for the sake of abstraction, and a certain amount of abstraction may go hand in hand with comparison; abstraction is for the sake of generalization, and generalization is not all done at one time, it weaves to and fro with the process of abstraction. Indeed, the whole series of processes may be gone through repeatedly in whole or in part, resulting in repeated modifications of the general notion, before the reflective reconstruction of the concept is complete. In this connection, it may be pointed out that application, or testing, of the concept by using it to interpret or control indi

viduals, which is really a deductive procedure, is an integral part of the whole process of generalization, and this too may be repeated many times before the satisfactory logical concept is attained.

While the idea of inductive method as a series of steps, each one complete in itself before the next is entered upon, breaks down; it still remains true that there are certain characteristic phases, or movements of thought, in the inductive process each one of which is necessary in some degree of its fulfilment to the next. These phases within the inductive movement of thought are bound together, guided, and directed by a common point of view which dominates the investigation throughout. That point of view is furnished by the central core of meaning embodied in the psychological concept which is being reconstructed. For example, the previously existing psychological concept trade center in our illustration functioned to guide and direct the various "steps" of investigation so that one "step" led rationally to the next and the results of one were directly relevant to the one which followed.

The line of thought which we have just developed is pedagogically significant in suggesting that there can be no true inductive process for the pupil until he has first gained a reasonable background of psychological notions which shall serve as the basis for the emergence of real problems and which shall also furnish guidance and control to the process of investigation. The relevancy of the inductive "steps" to one another cannot be felt by the pupil except as he has been made conscious of the nature of the problem involved. If the problem is given to him outright, it is purely formal, and all the steps in its solution are formal. It can be made real only by first developing something of a psychological notion out of the application of which the problem may naturally spring. If this is done, then the series of "steps" involved in inductive method may become relevant and dynamic.

5. INDUCTION of Laws and PRINCIPLES.

The same general point of view which we have developed in our discussion of the inductive process in its application to the class concept applies also to the case of laws and principles. We arrive at many laws and principles unreflectively, as, for example, the general law of plant growth, the law of the condensation of vapor, the principle that money is a medium of exchange, the principle that repetition fixes habit, etc. In the realm of laws and principles, the process of attaining logical notions is one that is subject to the same conditions as in the case of the class concept, namely, the breakdown, or failure in practice, of some psychological notion. This is the motive for the investigation of individual, or particular, cases with reference to the reconstruction of the law or principle. And the series. of inductive "steps" is the same as that already described. Sometimes, however, the breakdown of existing unreflective, or even reflective, notions is so complete that the guidance and direction of the inductive process is under the control of an hypothesis. The nature and function of the hypothesis we reserve for treatment in a later chapter.

6. UNREFLECTIVE DEDUCTION.

Deduction, like induction, as a movement of thought may be unreflective in character. Psychological concepts may not only arise unreflectively, but they may also be used unreflectively. In applying them as accepted and unquestioned to the interpretation and control of individuals we are proceeding deductively. This we are almost certain to do unreflectively in the case of psychological notions. But even if our concepts are logical, we may make an unreflective use of them.

A boy comes to a chestnut tree. He sees that the burs are opening, and he expects to find chestnuts on the ground. He has a general idea of the habit of the chestnut tree at this season of the year. In harmony with that accepted