Finally there is no new principle involved, if the action which is prepared by any belief has to set in after the awaking from hypnotic sleep, the so-called post-hypnotic suggestion. As a matter of course, just these have an eminent value for psychotherapy. I may suggest to-day that the subject will overcome to-morrow his desire for the morphine injection, or that he will feel to-night the restfulness which will overcome his insomnia. But if the suggestion of an idea means belief, and if belief means a preparation for action, we have indeed no new factor before us if the action for which we prepare the subject is from the start related to a definite time. If we do not link it with the consciousness of a special time or of a special occasion which will occur later, the suggestion soon fades away. That my library is an orchard is forgotten perhaps within ten minutes, if I have not come back to it in the conversation. But if I say that after awaking as soon as I shall knock on my desk three times, you will be in the orchard again, the psychophysical apparatus is prepared, a new setting has set in, the three knocks will bring about the complete transformation. In short the difficulties disappear as soon as we are consistent in interpreting all suggestive influences as changes in the motor setting and as the result of the antagonistic character of all of our motor paths. We say the difficulties disappear. Of course, that is meant in a relative sense only. It means essentially that we are able to bring the complex state of hypnotism down to the similar state of attention and motor adjustment, but of course we must not forget that we are far from a satisfactory explanation of the process in attention itself. We know that the opening of motor channels in one direction somewhat closes the channels for discharge in the opposite direction, but what mechanism does that work is still very obscure. Whichever principle of hypothetical explanation we might prefer, it certainly leads to difficulties in view of the extreme complexity of attention in states of suggestion and hypnotism. We might think of a mechanism which through the medium of the finest blood-vessels should produce a localized anaemia in those centers which lead to the antagonistic action. Or we might fancy that by extremely subtle machinery the resistance is increased in those tissues which lie between the various neurons, or we might even think of toxic and antitoxic processes in the cerebral regions; and any day may open entirely new ways of explanation. We may add that even if the mechanism of attention were completely explained, we are also still far from understanding the physiological changes which go on in the sphere of the blood-vessels or of the glands and the internal organs. We understand easily that the idea of the subject that he cannot move his arm keeps the arm stiff; but that his idea to blush really dilates the blood-vessels of his cheek is much less open to our causal