THE INTERRELATION OF INDUCTION AND DEDUCTION.--Induction and deduction must go hand in hand in building up our world of knowledge. Induction gives us the particular facts out of which our system of knowledge is built, furnishes us with the data out of which general truths are formed; deduction allows us to start with the generalization furnished us by induction, and from this vantage ground to organize and systematize our knowledge and, through the discovery of its relations, to unify it and make it usable. Deduction starts with a general truth and asks the question, "What new relations are made necessary among particular facts by this truth?" Induction starts with particulars, and asks the question, "To what general truth do these separate facts lead?" Each method of reasoning needs the other. Deduction must have induction to furnish the facts for its premises; induction must have deduction to organize these separate facts into a unified body of knowledge. "He only sees well who sees the whole in the parts, and the parts in the whole." 7. PROBLEMS IN OBSERVATION AND INTROSPECTION 1. Watch your own thinking for examples of each of the four types described. Observe a class of children in a recitation or at study and try to decide which type is being employed by each child. What proportion of the time supposedly given to study is given over to _chance_ or idle thinking? To _assimilative_ thinking? To _deliberative_ thinking? 2. Observe children at work in school with the purpose of determining whether they are being taught to _think_, or only to memorize certain facts. Do you find that definitions whose meaning is not clear are often required of children? Which should come first, the definition or the meaning and application of it? 3. It is of course evident from the relation of induction and deduction that the child's natural mode of learning a subject is by induction. Observe the teaching of children to determine whether inductive methods are commonly used. Outline an inductive lesson in arithmetic, physiology, geography, civics, etc. 4. What concepts have you now which you are aware are very meager? What is your concept of _mountain?_ How many have you seen? Have you any concepts which you are working very hard to enrich? 5. Recall some judgment which you have made and which proved to be false, and see whether you can now discover what was wrong with it. Do you find the trouble to be an inadequate concept? What constitutes "good judgment"? "poor judgment"? Did you ever make a mistake in an example in, say, percentage, by saying "This is the base," when it proved not to be? What was the cause of the error? 6. Can you recall any instance in which you made too hasty a generalization when you had observed but few cases upon which to base your premise? What of your reasoning which followed?