our inference. Verification involves the trying out of our inference to see that it certainly will hold. This may be done by proposing some other inference which we find to be invalid, or by seeking to find any other law or principle which will explain our particular situation. Here again, as in the inductive lesson, the skillful teacher makes his greatest contribution by having children become increasingly careful in this step of verification. Almost any one can pass through the several stages involved in deductive thinking and arrive at a wrong conclusion. That which distinguishes the careful thinker from the careless student is the sincerity of the former in his unwillingness to accept his conclusions until they are verified. _The Drill Lesson._ The drill lesson is so clearly a matter of fixing habits that little needs to be added to the chapter dealing with this subject. If one were to attempt to give in order the steps of the process involved, they might be stated as follows: (1) establishing a motive for forming the habit; (2) knowing exactly what we wish to do, or the habit or skill to be acquired; (3) recognition of the importance of the focusing of attention during the period devoted to repetitions; (4) variation in practice in order to lessen fatigue and to help to fix attention; (5) a recognition of the danger of making mistakes, with consequent provision against lapses; (6) the principle of review, which may be stated best by suggesting that the period between practice exercises may only gradually be lengthened. Possibly the greatest deficiency in drill work, as commonly conducted, is found in the tendency upon the part of some teachers to depend upon repetition involving many mistakes. This is due quite frequently to the assignment of too much to be accomplished. Twenty-five words in spelling, a whole multiplication table, a complete conjugation in Latin, all suggest the danger of mistakes which will be difficult to eliminate later on. The wise teacher is the one who provides very carefully against mistakes upon the part of pupils. He assigns a minimum number of words, or a number of combinations, or a part of a conjugation, and takes care to discover that children are sure of themselves before indulging in that practice which is to fix the habit.