In the conduct of an inductive lesson it is of primary importance that the teacher discover to children problems, the solutions of which are important for them, that he guide them in so far as it is possible for them to find all of the facts necessary in their search for data, that he encourage them to discuss with each other, even to the extent of disagreeing, with respect to comparisons which are instituted or generalizations which are premature, and above all, that he develop, in so far as it is possible, the habit of verifying conclusions. _The Deductive Lesson._ The interdependence of induction and deduction has been discussed in the chapter devoted to thinking. The procedure in a deductive lesson is from a clear recognition of the problem involved, through the analysis of the situation and abstraction of the essential elements, to a search for the laws or principles in which to classify the particular element or individual with which we are dealing, to a careful comparison of this particular with the general that we have found, to our conclusion, which is established by a process of verification. Briefly stated, the normal order of procedure might be indicated as follows: (1) finding the problem; (2) finding the generalization or principles; (3) inference; (4) verification. It is important in this type of exercise, as has been indicated in the discussion of the inductive lesson, that the problem be made clear. So long as children indulge in random guesses as to the process which is involved in the solution of a problem in arithmetic, or the principle which is to be invoked in science, or the rule which is to be called to mind in explaining a grammatical construction, we may take it for granted that they have no very clear conception of the process through which they must pass, nor of the issues which are involved. In the search for the generalization or principle which will explain the problem, a process of acceptance and rejection is involved. It helps children to state definitely, with respect to a problem in arithmetic, that they know that this particular principle is not the one which they need. It is often by a process of elimination that a child can best explain a grammatical construction, either in English or in a foreign language. Of course the elimination of the principle or law which is not the right one means simply that we are reducing the number of chances of making a mistake. If out of four possibilities we can immediately eliminate two of them, there are only two left to be considered. After children have discovered the generalization or principle involved, it is well to have them state definitely the inference which they make. Just as in the inductive process we pass almost immediately from the step of comparison and abstraction to the statement of generalization, so in the deductive lesson, when once we have related the particular case under consideration to the principle which explains it, we are ready to state