Trance, however, is not the only form of separate soul-existence that comes within the range of human experience. A very much more common occurrence is that of sleep. Here the scientist will hesitate a little before making any admission. The view now taken by Science of sleep is that the phenomenon is “a natural condition of insensibility, more or less complete, recurring normally (for the adult) with each night,” and further, that “the cause of sleep is undetermined, but is supposed to depend upon the production of sedative agents during our waking activities which ultimately clog the higher functions of the brain.” It is also held that “in natural deep sleep all the higher brain-centres are more or less out of action, together with the senses of sight, touch, taste, smell and hearing, though in varying degrees.” And, with regard to dreaming, the explanation given is that “the gradual passing of the higher nerve-centres--_i.e._ the highest centres of the cerebral matter--from normal to subnormal activity, or rest, removes from the lower centres a certain inhibition, and these respond more readily both to external stimuli and to altered internal stimuli or tension of the blood-vessels. Accompanying this functional dissolution of the higher centres there is, in varying degrees, dissociation of consciousness or obstructed association.... The result of such dissociation is interference with judgment, resulting in false perception, illusion, hallucination and perpetually altering variations of these.” What is meant by the phrase “dissociation of consciousness”? It cannot very well signify anything other than that consciousness during sleep becomes detached from the brain, sometimes to a partial extent and sometimes completely. This is the same thing as saying that soul is found by universal experience to exist, time and again, in a state of independence. To that extent the scientific view is well-founded and acceptable. When, however, dreams are stated to be nothing more than mere physical states of the lower brain-centres a doubt creeps in. Dreams are not material. They are intangible thoughts and belong to the domain of consciousness. Where the “removal of a certain inhibition from the lower centres” comes in is by way of explaining that owing to temporary physical conditions attending sleep, various brain-cells are out of gear, as it were, and work irregularly--the case being analogous to that of the man who is dumb or speaks badly owing to a blood-clot in his brain. But at the back of the fantastic or imperfect appearance are the consciousness and other elements of the soul marshalled in regular co-ordination. It is more probable, therefore, that dreams are distortions of realities perceived by the soul than that they originate in disordered cerebral matter. We see, then, that Science is faced by, and admits, three fundamental facts, namely-- 1. The existence, in this world, of human souls as well as human bodies.