§ 12. II. _One thing at a time._ Master one subject before you take up another. For each language master a single book. Go over it again and again till you have completely made it your own. In its crude form this rule could not be carried out. If the attempt were made the results would be no better than from the six months’ course of Terence under Ratke. It is “against all Nature” to go on hammering away at one thing day after day without any change; and there is a point beyond which any attempt at thoroughness must end in simple stagnation. The rule then would have two fatal drawbacks: 1st, it would lead to monotony; 2nd, it would require a completeness of learning which to the young would be impossible. But in these days no one follows Ratke. On the other hand, concentration in study is often neglected, and our time-tables afford specimens of the most ingenious mosaic work, in which everything has a place, but in so small a quantity that the learners never find out what each thing really is. School subjects are like the clubs of the eastern tale, which did not give out their medicinal properties till the patient got warm in the use of them. When a good hold on a subject has once been secured, short study, with considerable intervals between, may suffice to keep up and even increase the knowledge already obtained; but in matters of any difficulty, _e.g._, in a new language, no start is ever made without allotting to it much more than two or three hours a week. It is perhaps a mistake to suppose that if a good deal of the language may be learnt by giving it ten hours a week, twice that amount might be acquired in twenty hours. It is a much greater mistake if we think that one-fifth of the amount might be acquired in two hours. § 13. III. _The same thing should be repeated over and over again._ This is like the Jesuits’ _Repetitio Mater Studiorum_; and the same notion was well developed 200 years later by Jacotot. By Ratke’s application of this rule some odd results were produced. The little Koetheners were drilled for German in a book of the Bible (Genesis was selected), and then for Latin in a play of Terence.