For practical purposes it is advisable to consider the essential dynamic relationship between the four obvious elements of the problem of learning from books by the intensive study of them. These four elements we may denote as follows:—(1) the adequate textbook itself. (2) The real desire to learn its facts and its wisdom. (3) The forced and attentive study under the requisite pressure, great or small. (4) The transfer to the brain, and the associative process of interweaving with the knowledge and the wisdom already there. Of course there is every grade of learning-effort. When the effort based on interest is at its strongest, the outlines and some details of a whole new subject may be fixed in the mind in a few weeks or even in a few days. That is to say, this may readily be accomplished by a person who knows how to study, how especially to control his muscles and so to force his voluntary attention along the desired and, therefore, the interesting line of work. Obviously we are back again to generalized skill, the universal personal control over at least the voluntary muscles. It is sometimes actually surprising to observe how much of a new subject an active, vigorous boy or girl or an eager, hurried man can learn in a short time.
