"In induced sleep the subject's mind retains the memory of the person who has put him to sleep, whence the hypnotizer's power of playing upon his imagination, of suggesting dreams, and of directing the acts which are no longer controlled by the weakened or absent will." There are, in fact, many analogies between the phenomena of normal sleep and the phenomena of hypnotism. For instance, it is well known that the recollection of what occurred during hypnotic sleep is in exact inverse proportion to the depth of the sleep. If the sleep is light, the remembrance of the subject is perfect. If the sleep is profound, he remembers nothing, no matter what the character of the scenes he may have passed through. The same is true of dreams. We remember only those dreams which occur during the period when we are just going to sleep or are just awakening. Profound sleep is dreamless, so far as the recollection of the sleeper informs him. Nevertheless, it is certain that we dream continuously during sleep. The subjective mind is ever awake during the sleep of the body, and always active. Our dreams are often incoherent and absurd, for the reason that they are generally invoked by peripheral impressions. These impressions constitute suggestions which the subjective mind, in obedience to the universal law, accepts as true; and it always deduces the legitimate conclusions therefrom. For instance, it is probably within the experience of every reader that an accidental removal of the bed-clothing during a cold night will cause the sleeper to dream of wading through snow, or of sleigh-riding. And the dream will be pleasant or otherwise just in accordance with the character of the other attendant peripheral impressions. If the dreamer is in good health he will dream of pleasant winter scenes and experiences. If his stomach is out of order, or overloaded, he will have a nightmare, with a winter setting of ice and snow and all that is disagreeable, dank, and dismal. As we have seen in the preceding chapters, the subjective mind reasons deductively only from premises that are suggested to it, whether the suggestions are imparted to it by its physical environment, as in sleep, or by oral suggestion, as in hypnotism, or telepathically, as in the higher forms of mesmerism. Its deductions are always logical, whether the premises are true or false. Hence the absurdity of many of our dreams; they are merely deductions from false premises. The suggestions or impressions imparted to us during sleep being the result of accidental surroundings and stimuli, modified by the state of our health, our mental work during the day, and a thousand other things of which we can have no knowledge, and which are beyond our control, are necessarily of a heterogeneous character; and the deductions from such premises must of necessity be incoherent and fantastic to the last degree.