(3) _Allow no exceptions._ You should fully realize the great influence of exceptions. When you start in to form a habit, allow nothing to turn you from your course. Whether the habit is some fundamental moral habit or the multiplication table, be consistent, do not vacillate. Nothing is so strong as consistent action, nothing so weak as doubtful, wavering, uncertain action. Have the persistence of a bull dog and the regularity of planetary motion. =Transfer of Training.= Our problem now is to find out whether forming one habit helps one to form another. In some cases it does. The results of a recent experiment performed in the laboratory of educational psychology in the University of Missouri, will show what is meant. It was found that if a person practiced distributing cards into pigeon holes till great proficiency was attained, and then the numbering of the boxes or pigeon holes was changed, the person could learn the new numbering and gain proficiency in distributing the cards in the new way more quickly than was the case at first. Similarly, if one learns to run a typewriter with a certain form of keyboard, one can learn to operate a different keyboard much more quickly than was the case in learning the first keyboard. It is probable that the explanation of this apparent transfer is that there are common elements in the two cases. Certain bonds established in the first habit are available in the second. In the case of distributing the cards, many such common elements can be made out. One gains facility in reading the numbering of the cards. The actual movement of the hand in getting to a particular box is the same whatever the number of the box. One acquires schemes of associating and locating the boxes, schemes that will work in both cases. But suppose that one spends fifteen days in distributing cards according to one scheme of numbering, and then changes the numbering and practices for fifteen days with the new numbering, at the end of the second fifteen days one has more skill than at the close of the first fifteen days. In fact, in five days one has as much skill in the new method as was acquired in fifteen days in the first method. However, and this is an important point, the speed in the new way is not so great as the speed acquired in thirty days using one method or one scheme all the time. Direct practice on the specific habit involved is always most efficient.