It becomes necessary at this point to take up a reverse side of our study, namely, what is often called the influence of "mind over matter." Such cures of disease as seem to follow prayer and faith are cited; such incidents as the great strength of men under emotion or the disturbances of the body by ideas are listed as examples. This is not the place to discuss cures by faith. It suffices to say this: that in the first place most of such cures relate to hysteria, a disease we shall discuss later but which is characterized by symptoms that appear and disappear like magic. I have seen "cured" (and have "cured") such patients, affected with paralysis, deafness, dumbness, blindness, etc., with reasoning, electricity, bitter tonics, fake electrodes, hypnotism, and in one case by a forcible slap upon a prominent and naked part of the body. Hysteria has been the basis of many a saint's reputation and likewise has aided many a physician into affluence. Nor is the effect of coincidence taken into account in estimating cures, whether by faith or by drugs. Many a physician has owed his start to the fact that he was called in on some obscure case just when the patient was on the turn towards recovery. He then receives the credit that belonged to Nature. Medical men understand this,--that many diseases are "self-limited" and pass through a cycle influenced but little by treatment. But faith curists do not so understand, and neither does the mass of people, so that neither one nor the other separates "post hoc" from "propter hoc." If the truth were told, most of the miracle and faith cures that are not of hysterical origin are due to coincidence. Faith curists report in detail their successes, but we have no statistics whatever of their failures. If thought is a product of the brain activated by the rest of the organism, it would be perfectly natural to expect that thought would influence the organism. That thought is intimately associated with impulses to action is well known. This action largely takes place in the speech muscles but also it irradiates into the rest of the organism. Especially is this true if the thought is associated with some emotion. Emotion, as we shall discuss it later, is at least in large part a bodily reaction, a disturbance in heart, lungs, abdominal organs, blood vessels, sympathetic nervous system, endocrines, etc. The effect of thought and emotion upon the body, whether to heighten its activity or to lower its activity, is, from my point of view, merely the effect of one function of the organism upon others. We are not surprised if digestion affects thinking and mood, and we need not be surprised if thought and mood disturb or improve digestion. And we may substitute for digestion any other organic function.