Habitual lack of firmness in the jaw muscles, as you know, results in a sagging chin; which detrimentally affects the brain-mind center of persistence.  A man whose jaw habitually hangs loose may be capable of great determination for a while, but he is not persistent in character.  He might clench his teeth, stiffen his body, and plunge into the surf to rescue a drowning person; but his first resolution to effect the rescue would be weakened by the cold water and by fear.  He lacks the quality of the bulldog that will die rather than loose its teeth from another dog’s throat.

[Sidenote:  Muscles Express and Impress Ideas]

The coordinated muscles express the mental attitude, as we have perceived; and equally they impress the mind with their attitude.  If you have a sagging chin, you are incapable of the mental bulldog grip of persistence.  So tighten up your jaw muscles, and never let them hang utterly loose, if you are resolved to develop the characteristic of “stick-to-it-iveness.” Begin with muscle training, for your muscles must be utilized to start the process of building up your brain-mind center of persistence.

[Sidenote:  Developing Perception]

When you train the particular sense muscles that transmit external impressions to a particular brain-mind unit (the same muscles that reflexively express the ideas of that one part of your multiplex ego) you may be absolutely sure of developing a particular related characteristic.  For example, if you want to sharpen your perceptive faculties so that you will see with the eyes of your mind much more than the ordinary man perceives, exercise your physical eyes in taking snap-shots that you can see clearly in detail with your imagination when you look away from an object after a glance at it.  Try glancing at the furnishings of your room, then shut your eyes and construct a mental picture.  When this is definitely clear to you, open your eyes.  The reality will be very different from your imagined picture.  But sharpen your perceptive faculties, develop a “camera eye;” then the reality will be exactly impressed on your mind.  Witnesses in court often contradict one another, in all honesty, simply because their ability to perceive actualities is not highly developed.  In consequence, they get false mental impressions of happenings or things they severally have seen.

[Sidenote:  Three Processes Of Mental Development]

There are but three processes of mental development: 

The first process comprises getting information from a sense to its associated brain center, which then makes the mind center conscious that particular information has been transmitted to it.

The second process is organizing the information in the mind center, with relation to other information previously brought to the mind.