(9) _Multiple Line of Approach._--The language should be approached simultaneously from many different sides in many different ways, by means of many different forms of work.
Text-books may differ in the sort of material supplied; teachers may differ in their mode of presentation; there will be room for individuality and personality. For years to come we shall not secure perfect uniformity and ideal results, but if these nine essential principles are understood and reasonably well observed by the method-writer, course-designer, and teacher, the resultant teaching is bound to be good and the results are bound to be satisfactory.
In the first chapter we have seen that each of us, child or adult, possesses in either an active or a latent state certain capacities for the spontaneous assimilation of the spoken and colloquial form of any given language, native or foreign. In the case of the young child, these capacities are in an active state and at his immediate service, he does not require to be trained in their use; in the case of the average adult, these capacities are in a latent state, they have fallen into disuse, they are not at his immediate service, he must train himself to use them, he must learn how to learn.
In the first place, he must realize that language-learning (within the scope of our definition) is an _art_ and not a _science_; to become proficient in an _art_ is to acquire the capacity for _doing_ something; to become proficient in a _science_ is to acquire _knowledge_ concerning something. So long as the student treats language-study as a science he will make little or no progress in the art of using language.
Now, there are two possible ways of acquiring proficiency in an art; the one consists in applying theory, the other consists in persistent efforts to imitate the successful performances of others. Let us say that the student wishes to use the French equivalent of 'she went.' By the method of theory he will remember that past actions are generally expressed by the French _passé indéfini_ (or _perfect_); he will then remember that this tense is formed by means of one of the two auxiliaries plus the past participle. His knowledge of theory will tell him to derive from the infinitive _aller_ the past participle _allé_; theory will also tell him that this particular verb requires the auxiliary _être_ and not _avoir_, and that the present tense third person singular of _être_ is _est_. If he is writing the sentence, he must remember that the participle must in this case agree with the subject and be spelt _allée_.