This section is from the book "Concentration", by Christian D. Larson. Also available from Amazon: Concentration And The Power Back Of Suggestion.
THE greatest faculty of all is that of imagination; but it is the least understood, due principally to the fact that most minds have remained in grooves of thought, and therefore have not given extensive attention to their own creative possibilities, the richest and most numerous of which exist in the fields of imagination. In the development of any power or talent, however, these creative possibilities must receive direct and scientific attention; and this is especially true with regard to the power of concentration. Besides, some of the functions of concentration are so closely related to those of imagination as to seem almost identical. When you employ the faculty of imagination, one of your chief objects is to bring together ideas or mental images with a view of creating some new or greater idea; and in concentration this "bringing together" tendency - this uniting the many in one, is the leading object in view. It is clearly evident therefore that a better training of imagination will largely increase the power of concentration.
When you employ the faculty of imagination, you also tend to bring together the many creative energies of the mind, combining those energies in the one process to which you are giving attention at the time. A highly developed faculty of imagination therefore naturally becomes an invaluable aid to the power of concentration; and when we understand how concentration can, by working with imagination, bring together, into one powerful line of mental action, all the best ideas of the mind and all available creative energy, we know why we usually find an excellent imagination wherever we find a remarkable concentration.
Analyzing the subject farther, we find that a vivid, well-trained imagination tends to "light up" the entire mental world; or, in other words, to make everything in the mind more clear. The result is, that the idea or object upon which we concentrate becomes more distinct; and accordingly, we not only concentrate better, but the entire mind becomes interested in this idea on account of its vividness and distinctiveness. Thus we call into action the many aspects of mental attention, an action that increases directly and instantaneously the power of concentration. We all know through experience how much better we can think when the ideas with which we are dealing are vivid, or stand out clearly in the mind; and also how much better we can concentrate when we have a distinct mental picture of the object in view. And imagination, if well trained and scientifically applied, will invariably turn the light upon any idea that we may call up for examination or further development.
When imagination is vivid, every mental process will be literally filled and surrounded with light; and we all can appreciate what an immense advantage this will be in the practical application of concentration. To illustrate, we will call imagination into action wherever we wish to concentrate, and immediately that place or process in the mind will become so vivid, and stand out so clearly, that all our faculties will become interested. The entire mind will turn its attention towards the point of concentration; and in a moment the entire mind will concentrate. And when we have the whole mind working for the object in view, the results desired will positively be realized.
As a practical suggestion we should, whenever we begin to concentrate, proceed to imagine all the forces of the mind coming to a focus at the point of concentration. This simple rule will not only produce some startling results in the process of concentration itself, but will also train imagination for definite and practical work. Herewith, let us note that imagination does have the power to take the lead in the mental world; and therefore whenever we imagine that a certain thing is being done in the mind, we lead a majority of the energies of the mind to go and do that very thing; provided of course that imagination be vivid and highly positive in its actions. Here then we have within easy reach a most remarkable possibility.
 
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