3. The law of _vividness of impression_. The relation of vividness of impression to learning has already been discussed in another chapter. In no one of the mind's activities is vividness a more important factor than in memorizing. Matter committed under the stimulus of high interest and keen attention is relatively secure, while matter committed under slack concentration is sure to fade quickly from the memory. Songs can therefore best be committed under the elation of the interesting singing of the words; a verse of poetry, when the mind is alert and the feelings aroused by a story in which the sentiment of the verse fits; a prayer when the spirit of devotion has been quickened by worship. To insure full vividness the imagination must also be called upon to picture and make real such parts of memory material as contain imagery. 4. The law of _repetition_. For most minds memory depends on repetition. The impressions must be deepened and made lasting by being stamped again and again on the mind. The neurons of the brain which do the work of retaining and recalling must be made to repeat the process over and over until their action is secure. It is therefore not enough to make sure that the child has his memory material committed for this particular Sunday. If the matter was worth committing in the first place, it is worth keeping permanently. If it is to be kept permanently, it must be frequently reviewed; for otherwise it will surely be forgotten. It is to be feared that much, if not most, of the matter memorized by the pupils in many church schools lasts only long enough to show the teacher that it has once been learned, and that not many children know in any permanent sense the Bible passages they have committed. In so far as this is true it would be much better to select a smaller amount of the choicest and best adapted material to be found, and then so thoroughly teach this that it is permanently retained. 5. The law of _wholes instead of parts_. Many persons in setting at work to commit a poem, a Bible passage, a psalm have a tendency to learn it first by verses or sections and then, put the parts together to form the whole. Tests upon the memory have shown, that this is a less economical and efficient method than from the first to commit the material as a whole. This method requires that we go over all of it completely from beginning to end, then over it again, and so on until we can repeat much of it without reference to the text. We then refer to the text for what the memory has not yet grasped, requiring the memory to repeat all that has been committed, until the whole is in this manner fully learned. The method of learning by wholes not only requires less time and effort, but gives a better sense of unity in the matter committed.