THE RELATIONS OF MINDS TO OTHER THINGS. 201 In somnambulism, natural or induced, there is often a great display of intellectual activity, followed by complete oblivion of all that has passed.* On being suddenly awakened from a sleep, however pro- found, we always catch ourselves in the middle of a dream. Common dreams are often remembered for a few minutes after waking, and then irretrievably lost. Frequently, when awake and absent-minded, we are visited by thoughts and images which the next instant we cannot recall. Our insensibility to habitual noises, etc., whilst awake, proves that we can neglect to attend to that which we never- theless feel. Similarly in sleep, we grow inured, and sleep soundly in presence of sensations of sound, cold, contact, etc., which at first prevented our complete repose. We have learned to neglect them whilst asleep as we should whilst awake. The mere sense-imjjressions are the same when the sleep is deep as when it is light ; the difference must lie in a judgment on the part of the apparently slumbering mind that they are not worth noticing. This discrimination is equally shown by nurses of the sick and mothers of infants, who will sleep through much noise of an irrelevant sort, but waken at the slightest stir- ring of the patient or the babe. This last fact shows the sense-organ to be pervious for sounds. Many people have a remarkable faculty of registering when asleep the flight of time. They will habitually wake up at the same minute day after day, or will wake punctu- ally at an unusual hour determined upon overnight. How can this knowledge of the hour (more accurate often than anything the waking consciousness shows) be possible without mental activity during the interval ? Such are what we may call the classical reasons for ad- mitting that the mind is active even when the person after- wards ignores the fact.f Of late years, or rather, one may
- That the appearance of mental activity here is real can be proved by
suggesting to the ' hypnotized ' somnambulist that he shall remember when he awakes. He will then often do so. f For more details, of. Malebranche, Rech. de la Verite, bk. in. chap, i; J. Locke, Essay cone. H. U., book ii. ch. i; C. Wolf, Psychol.
