In sleep the conditions are favorable for this readjustment, and the subliminal self comes more or less perfectly to the surface; then appears that most peculiar and interesting series of pictures and visions which we call dreams; sometimes the rearranged, or rather unarranged, impressions and perceptions of the waking hours brought together, possibly just before the power of attention is entirely lost; sometimes the Puck-like work of the subliminal personality, the Léontines of the dream-country influencing the unconscious or semi-conscious primary self; sometimes the veridical or truth-telling dreams, which have been the wonder of all ages, and sometimes giving complete and active supremacy to the subliminal self as in natural somnambulism. Another portion of the field in which it might be profitable to look for evidence of the existence of a subliminal personality is in the eccentric work of genius; and still another, in the unexpected and often heroic actions of seemingly ordinary persons under the stress and stimulus of a great emotion, as of joy, sorrow, or anger, or of intense excitement, as for instance, the soldier in battle, the fireman at the post of danger, or the philosopher or astronomer on the eve of a new discovery; in all these cases the ordinary personality with its intense self-consciousness and self-considering carefulness is submerged--it disappears--the power of voluntary attention to mental states or physical action is lost; a new and superior personality comes to the surface and takes control. The supreme moment passes, and the primary self resumes sway, scarcely conscious of what has been done or how it was accomplished; even sensation has been abolished, and it is only now that he discovers the bleeding bullet-wound, the charred member, or the broken bone. In physical science, whenever some new fact or law or principle has been discovered, it is at once seen that many things which before were obscure, or perhaps could only be accounted for by a theory of chance, or of direct interference by an omnipotent Deity, are now illuminated by a new light, and order reigns where before only confusion and darkness were visible. Something of the same sort is beginning to be recognized in the world of mental and psychical phenomena. If the mathematical exactness which measured the force of gravity, or placed the sun in one of the foci of an ellipse instead of the centre of a circle cannot be applied here, it is only on account of the vast complexity of the problem presented, and of which we know so few of the elements.