In the third process the mind center directs its co-related brain center to send out certain impulses of action to the corresponding muscular structure.

Let us analyze an illustration of these three processes of mental development.  Suppose first you hear something that concerns a particular prospect for your “goods of sale.”  Second, you comprehend the significance to you of what you have heard.  Third, your mind directs your muscles to make a particular use of what you have comprehended.  The original mental impression has been fully developed because you employed all three processes.  If you had not completed the cycle of development, you would have given your mind only partial exercise with what you heard.

In order to become a master salesman, you must take in many impressions, perceive their significance to you and how you can make use of them, then act on your comprehension of what you have learned.  There are countless failures in the world who might have been successes if they had not stopped their possible mental development at the first or second stages.

A man might know an encyclopedia of facts, but be a failure.

He might comprehend how to use his knowledge, and still be a failure.

Success comes only to the man who acts most effectively on what he knows.

[Sidenote:  Right Practice Of the Three Processes]

In order to secure quick and effective results, the practice of the three necessary processes of development should be: 

First, definitely conscious.  You need to know just what quality you want to develop in yourself.

Second, discriminative.  You must learn the differences between what you want, and what you don’t want to develop in particular.

Third, restrictive.  It is necessary that in your training to develop a certain quality, you concentrate your practice on the respects in which this particular quality differs from other qualities.

Most of us are pretty definitely conscious of what we want.  We know just the qualities we would like to have.  But very few people employ most effectively the discriminative-restrictive methods of training in their processes of development.

[Sidenote:  Importance of Differentiation]

It is impossible to develop a particular quality fully if you only recognize its likenesses to other qualities. Real mental development is accomplished only as a result of the recognition of differences.  After studying twins for a year, you still might be unable to tell them apart if you were impressed solely with their remarkable similarity to each other.  Another man, with a mind discriminatively and restrictively trained to recognize differences, would learn in five minutes to distinguish the individualities of the twins.