Coming back, then, to the common law which underlies all cases or forms of mental healing, we find two general principles upon which it is built--the power of the mind over the body, and the importance of suggestion as a factor in the cure of the disease. The law may be tersely stated in the first person as follows: My body tends to adjust itself so as to be in harmony with my ideas concerning it. This law is equally applicable to the cause or cure of disease by mental means. To apply this law in a universal way as far as mental healing is concerned, we should notice that however the thought of cure may come into the mind, whether by external or auto-suggestion, if it is firmly rooted so as to impress the subconsciousness, that part of the mind which rules the bodily organs, a tendency toward cure is at once set up and continues as long as that thought has the ascendancy. Hack Tuke quotes Johannes Mueller, a physiologist who lived during the first half of the last century, as follows: "It may be stated as a general fact that any state of body which is conceived to be approaching, and which is expected with certain confidence and certainty of occurrence, will be very prone to ensue, as the mere result of the idea, if it do not lie beyond the bounds of possibility." This is a fair statement of the law from the stand-point of consciousness, but does not include all of the vast influence of subconscious ideas which are so potent in the cure of diseases by mental means. Mueller's observation was in advance of his times, but could not be expected to include the results of the latest researches of modern science. For a great many years physicians have recognized that not only are all diseases made worse by an incorrect mental attitude, but that some diseases are the direct result of worry and other mental disturbances. The mental force which causes colored water to act as an emetic, or postage-stamps to produce a blister, can also produce organic diseases of a serious nature. The large mental factor in the cause of diseases is generally admitted, and it seems reasonable to infer that what is caused by mental influence may be cured by the same means. There is no restriction in the power of the mind in causing disease, and should we restrict the mind as a factor in the cure? The trouble seems to be in the explanation. People ask, "How can the mind have such an effect upon the body?" and to the answer of this question we must now turn our attention.