"These facts, then, seem to prove that suggestion may act upon the cardiac function and upon the vaso-motor system. Phenomena of this order, however, rarely occur. They are exceptional, and are obtained in certain subjects only. I have in vain tried to reproduce them in many cases. These facts are sufficient to prove, however, that when in a condition of special psychical concentration, the brain can influence even the organic functions, which in the normal state seem but slightly amenable to the will."[28] These facts demonstrate at once the correctness of two of the fundamental propositions before stated; namely, the constant amenability of the subjective mind to the power of suggestion, and the perfect control which the subjective mind exercises over the functions, sensations, and conditions of the body. All the foregoing phenomena represent abnormal conditions induced by suggestion, and are, as before stated, all the more conclusive proofs of the potency of the force invoked. If, therefore, there exists in man a power which, in obedience to the suggestion of another, is capable of producing abnormal conditions in defiance of the natural instincts and desires of all animal creation, how much more potent must be a suggestion which operates in harmony with the natural instinctive desire of the patient for the restoration of normal conditions, and with the constant effort of nature to bring about that result! At the risk of repetition, the self-evident proposition will be restated, that the instinct of self-preservation is the strongest instinct of our nature, and constitutes a most potent, ever-present, and constantly operative auto-suggestion, inherent in our very nature. It is obvious that any outside suggestion must operate with all the greater potentiality when it is directed on lines in harmony with instinctive auto-suggestion. It follows that normal conditions can be restored with greater ease and certainty, other things being equal, than abnormal conditions can be induced. And thus it is that by the practice of each of the various systems of psycho-therapeutics we find that the most marvellous cures are effected, and are again reminded of the words of Paracelsus: "Whether the object of your faith be real or false, you will nevertheless obtain the same effects." This brings us to the discussion of the essential mental condition prerequisite to the success of every experiment in psycho-therapeutics,--faith.