If we go to slang, which offers the line of least resistance to the Cosmic Law, we find that the cue has been given over and over again to those who are interiorly awake to receive it. "You are not in on this," has been said to one who was left out of some supposedly desirable thing; or "you are not _in_ it," meaning that you are not up to the required standard. Even as the walls of a building only imperfectly indicate the nature of that which is within, that which the building stands for; that which it symbolizes, so physical appearances are symbolical hieroglyphs of the inner nature. "Learn to look into the hearts of men" admonishes the spiritual teacher. "As a man thinketh in his heart so is he." The character of the heart is the test, and though a man's lips utter words that are at variance with his inner nature, yet if we have learned to look within, we are not deceived. This then is the key to the kingdom--interior vision. Words are like buildings; like personalities; they have their exterior and their interior message. Knowledge may be accumulated; piled up like a mountain of possessions. But knowledge may not bestow one grain of true wisdom. It is only as we extract the interior message from knowledge that we attain wisdom. We possess knowledge and we _find_ wisdom, when we have transmuted that knowledge into its interior meaning. The fundamental difference between mysticism and theology is a difference founded upon this axiom. The true mystic penetrates to the interior nature of manifestation and gets the message of Experience. Mysticism excludes nothing. It includes the manifest with the interior; it penetrates the outer and seeks the interior; but never does the true mystic confound the spirit with the letter; never does he mistake the external for the Reality; the symbol for the message. Suppose that what is generally called the practical side of life were the only reality. What would be the inevitable conclusion of the thinker if he were to consider only the outer, the manifest, the visible results of a given achievement? He would conclude that civilization is insane. If we did not know with an intuitional grasp of truth that all this which we call "marvels of achievement" is symbolical of what Man is in his interior nature, it would be the veriest folly. What, for example, is there in a modern sky-scraper indicative of man's advanced civilization?