4. _Spiritism_, which is a system of healing based on the supposed interposition of spirits of the dead, operating directly, or indirectly through a medium, upon the patient. 5. _Mesmerism._--This includes all the systems of healing founded on the supposition that there exists in man a fluid which can be projected upon another, at the will of the operator, with the effect of healing disease by the therapeutic action of the fluid upon the diseased organism. 6. _Suggestive Hypnotism._--This method of healing rests upon the law that persons in the hypnotic condition are constantly controllable by the power of suggestion, and that by this means pain is suppressed, function modified, fever calmed, secretion and excretion encouraged, etc., and thus nature, the healer, is permitted to do the work of restoration. Each of these schools is subdivided into sects, entertaining modified theories of causation, and employing modified processes of applying the force at their command. There is but one thing common to them all, and that is that they all cure diseases. We have, then, six different systems of psycho-therapeutics, based upon as many different theories, differing as widely as the poles, and each presenting indubitable evidence of being able to perform cures which in any age but the present would have been called miraculous. The most obvious conclusion which strikes the scientific mind is that there must be some underlying principle which is common to them all. It is the task of science to discover that principle. It will now be in order to recall to the mind of the reader, once more, the fundamental propositions of the hypothesis under consideration. They are,-- First, that man is possessed of two minds, which we have distinguished by designating one as the objective mind, and the other as the subjective mind. Secondly, that the subjective mind is constantly amenable to control by the power of suggestion. These propositions having been established, at least provisionally, by the facts shown in the foregoing chapters, it now remains to present a subsidiary proposition, which pertains to the subject of psycho-therapeutics, namely:-- _The subjective mind has absolute control of the functions, conditions, and sensations of the body._