My friend Mr. A., who is much interested in mental problems, has practised introspection with assiduity and care. He finds that if he fixes his attention on some given word, and then allows his hand to rest laxly in the writing attitude, his hand presently writes the word without any conscious volition of his own; the sensation being as though the hand were moved by some power other than himself. This happens whether his eyes are open or shut, so that the gaze is not necessary to fix the attention. If he wills _not_ to write, he can remove his hand and avert the action. But if he chooses a movement simpler than writing, for instance, if he holds out his open hand and strongly imagines that it will close, a kind of spasm ensues, and the hand closes, even though he exert all his voluntary force to keep it open. It is manifest how analogous these actions are to much which in bygone times has been classed as _possession_. Mr. A. has the very sensation of being possessed,—moved from within by some agency which overrules his volition, and yet we can hardly doubt that it is merely his _unconscious_ influencing his _conscious_ life. The act of attention, so to say, has stamped the idea of the projected movement so strongly on his brain that the movement works itself out automatically, in spite of subsequent efforts to prevent it. The best parallel will be the case of a promise made during the hypnotic trance, which the subject is irresistibly impelled to fulfil on waking.[28] From this curious transitional case we pass on to cases where no idea of the words written has passed through the writer’s consciousness. It is not easy to make quite sure that this is the case, and the _modus operandi_ needs some consideration.