The best way to learn a principle is not to memorize it, but to understand it. Learn, if possible, the reason for its existence, at least in a general way; the laws which underlie it, and the facts upon which it is based. The student who memorizes the words, “all bodies attract one another directly in proportion to their mass and inversely in proportion to the square of the distance between them,” knows little or nothing about the law of gravitation, while the student who understands just what those words mean, whether he is able to repeat them correctly or not, does know the law of gravitation, and, if necessary, can probably apply it. The boy who learns that any object weighs less on a mountain-top than at the sea level learns an interesting and perhaps valuable fact. The man who learns that the law involved in this fact is the law of gravitation has learned something which he may be able to apply in a thousand ways. The man who, in the future, may learn why the law of gravitation operates as it does, may open untapped reservoirs of power for himself, for all humanity, and for all future generations. Therefore, in learning a principle, learn not only to understand it, but, if possible, why.
Having gained as complete as possible an understanding of the laws and principles of the science of character analysis, the next step is to demonstrate to your own satisfaction that they are sound. This process will also enable you to understand them even more definitely and specifically than before.
When you learn, for example, that a blonde is more volatile, more fond of change and variety, more inclined to pioneering and government, than the brunette, you have learned an important law. When you study carefully the history of the evolution of the blonde and brunette races, you know why the law is as it is. But when you have gone out and observed several hundred blondes and several hundred brunettes and have seen them manifest dispositions, aptitudes and characteristics in accordance with the law, you have not only demonstrated the law to your own satisfaction, but you understand it even better than before. Furthermore, you are far better able than ever to determine the characteristics of the people you meet, as indicated by their color.
There are many good reasons why the very first application of the knowledge of the principles and laws of character analysis should be to yourself. While, in one sense, you know your own thoughts and feelings and innermost desires and ambitions better than anyone else does, in another and very important sense, your friends and relatives probably understand you far better than you understand yourself. If you need any demonstration of this truth, look for it amongst your relatives and friends. You may have a relative,