Beginning our consideration of the Mind of the Salesman, let us realize that upon his mind depends his character and personality. His character is composed of his individual mental qualities or attributes. His personality is his customary outward expression of his character. Both character and personality may be altered, changed and improved. And there is in each person a central _something_ which he calls "I," which is able to order and manifest these changes in his character and personality. While it may be argued plausibly that a man is merely a composite of his characteristics and nothing more, nevertheless there is always in each the consciousness that in his real "I" there is a something which is above and behind characteristics, and which may regulate the latter. Without attempting to lead the reader into the maze of metaphysics, or the pitfalls of philosophy, we wish to impress upon him the fact that his mental being has for its innermost centre of consciousness this mysterious "I," the nature of which no one has ever been able to determine, but which when fully realized imparts to one a strength and force undreamed of before. And it is well worth while for everyone seeking self-development and self-improvement to awaken to a clear realization of this "I" within him, to which every faculty, every quality, every characteristic is an instrument of expression and manifestation. The real "you" is not the characteristics or features of personality, which change from time to time, but a permanent, changeless, centre and background of the changes of personality--a something that endures through all changes, and which you simply know as "I." In the volume of this series, entitled "_The New Psychology_," in the chapter entitled "The Ego, or Self" we have spoken of this in detail. Further mention would be out of place in the present volume, but we may be pardoned for quoting the following from the said chapter, for we feel that a realization of this "I" is most important to each person who wishes to master his own mind, and to create his own personality. Here follows the quotation: