rustle in our surroundings, even by the pulsing of the blood through its own vessels. Here, indeed, we raise the whole difficult question of _the origination of dreams_. We cannot say that a dream may not arise ‘in the brain’ altogether apart from stimulation of a sense-organ; yet the sense-organs are always liable to stimulation, from without or from within; we know that stimuli, too weak to arouse a sleeper, will set up dreams; and it seems safe to conclude that most dreams are originated by sensory stimulation, while their subsequent course is due to associative and perhaps to determining tendencies active at the moment. Attempts have been made to refer certain familiar kinds of dream—dreams of flying, falling, appearing in public scantily clothed, preparing for a journey, etc.—to particular forms of stimulus: arrest of heart-beat, irregular breathing, cold from the slipping down of bed-clothes, etc.; but no positive correlation has been arrived at. _Dreams are ordinarily regarded as the type of fantastic and disordered experience_, “the children of an idle brain, begot of nothing but vain fantasy”; and some dreams, it is true, are very fragmentary, and some dream-combinations seem ridiculous enough to the waking judgement, and some shifts of dream-scene are startlingly abrupt. It may be questioned, nevertheless, whether the changes are in fact more sudden or more radical than those of the waking life, and whether the grouping is more fantastic than in the day-dream. _The great perceptive attitudes remain for the most part unchanged._ We notice, on later reflection, that time may be curiously foreshortened, so that we have the events of a day crowded into a few seconds; but this is due partly to the occurrence of attitudes, of the nutshell-packing of experiences (p. 271), such as we find also in our waking memories, and partly to our own reflective reading of the dream; we, who are now awake, distribute the events over a day, much as the novelist may do in telling his story, or the playwright in developing his plot. _The sense of personal identity is rarely lost_; and the dream frequently reflects the personality of the dreamer; temperament, interests, principles, show themselves in it; no one of us could dream his neighbour’s dreams. In general, too, _the dream plays about a topic or situation_; and if the changes are both sudden and profound, we must remember that our waking trains are held in course, as dreams are not, by the continuity of the stimuli around us, and that even so we are often interrupted in a current train, and shift from topic to topic at a moment’s notice. The dream is under no external control by an environment, nor is it as a rule organised and regulated throughout by a dominant determining tendency, as is the case with thought and constructive imagination. It is subject, however, to the laws of associative tendency, and sometimes at any rate it seems to issue from