Humanity is only just beginning to realize the sovereign power a man may exercise over his own thought and action. It is no longer so universally believed that the state of a man's mind is largely determined by his physical or material condition, for the admission advances that thought is cause, not effect. Although this order, which recognizes thought as preceding condition and action, even that action which mortals have classified as involuntary, seems novel to this age, the teaching is not new, for Jesus the Christ declared that material conditions could not of themselves affect the man, but that, as he said, "out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies: these are the things which defile a man."

While it is possible for every one to hold to right thought and to reject the wrong, to do so intelligently and uniformly, requires a knowledge of the Science of Mind, just as expert application of the rule of numbers demands some comprehension of mathematics. Through the use of human will, a man may, to be sure, concentrate upon any given endeavor, or he may, through the same agency, refuse to dwell upon unpleasant things; but in so far as he attempts to control and direct his thought through material will, he violates the fundamental postulate of the Science of Mind, that God is the only intelligence. So all that a man accomplishes through will power is to replace one trend of human thought with another quite as material and unreal.

To judge whether one is thinking aright, one must begin with God as the source of all real thought. Then he will see that divine Mind is manifested in thoughts which lead mankind toward the spiritual facts of being and into harmony and holiness. He will also learn that scientific right thought not only has power to establish his own sense of health, happiness, and prosperity on a spiritual and immortal foundation, but that it is also potent to destroy wrong thoughts and their effects for others. It was upon this understanding of God as the Principle of all true intelligence that Mrs. Eddy based her declaration, on page 252 of "Miscellaneous Writings": "Christian Science classifies thought thus: Right thoughts are reality and power; wrong thoughts are unreality and powerless, possessing the nature of dreams. Good thoughts are potent; evil thoughts are impotent, and they should appear thus. Continuing this category, we learn that sick thoughts are unreality and weakness; while healthy thoughts are reality and strength. My proof of these novel propositions is demonstration, whereby any man can satisfy himself of their verity."

This teaching, that as a man thinks spiritual thoughts he approaches holiness and harmony, need not frighten the man engaged in material pursuits into believing that so transcendental a course would necessarily sever him from his chosen work. Whether he is willing or not to admit the fact and to face the consequent responsibility, the material things with which the business man believes he deals, are actually nothing but thought made manifest. If, then, things and affairs in their essence are thoughts, it is almost too obvious to need exposition that they can be controlled and brought to satisfactory consummation only as the thought which produces them itself conforms to the divine Principle of harmony and success; or, to phrase it a little differently, when consciousness as good is admitted as the only reality, good will be seen manifested everywhere. The process of "casting down imaginations, and every high thing that exalteth itself against the knowledge of God," to use Paul's phrase, "and bringing into captivity every thought to the obedience of Christ," does not bring a man less, but more, of freedom in his business connections, and instead of diminishing his sense of substance and power, it gives him access to the unlimited abundance of God, in just the ratio that he gains the Mind of the Christ, the Mind which enabled Jesus to rise superior to every supposed law and limitation of economics, physics, and physiology.

Starting from a human standpoint, however, and endeavoring to approach pure Mind, involves knowing how to recognize, in order to reject, erroneous thought. This instruction Christian Science supplies. The human mind persistently attempts to reverse divine Truth and would draw spiritual ideas within the confines of material belief. Anatomy, to take only one example from the many branches of human knowledge, is distorted to mean the dissection of material physical structure. Translated from matter to the realm of thought, as all material modes must finally be, anatomy becomes the means whereby a man may learn to analyze, classify, and correct human thought. Mrs. Eddy scientifically resolved anatomy from its false material meaning into an illumined mental process, when she wrote, on page 462 of Science and Health: "Anatomy, when conceived of spiritually, is mental self-knowledge, and consists in the dissection of thoughts to discover their quality, quantity, and origin. Are thoughts divine or human? That is the important question. This branch of study is indispensable to the excision of error."

The practice of this true sense of anatomy, or self-knowledge, is only for the purpose of discovering and dismissing wrong thoughts, not of dwelling upon them. To discuss or to think again the thoughts which have been shown to be material and unreal, would be analogous to repeating a mistake which has been uncovered in mathematical calculation. To human sense it may not seem easy to replace evil or random thoughts with exact, scientific thinking, but it is the way of salvation from materiality and its penalty. Through scientific right thought, God becomes All, practically, and the Science of perfect Mind and divine healing is demonstrated. Recognizing humanity's great need of thinking in accordance with divine Principle, Mrs. Eddy wrote (Miscellany, p. 210): "Beloved Christian Scientists, keep your minds so filled with Truth and Love, that sin, disease, and death cannot enter them. It is plain that nothing can be added to the mind already full. There is no door through which evil can enter, and no space for evil to fill in a mind filled with goodness. Good thoughts are an impervious armor; clad therewith you are completely shielded from the attacks of error of every sort."