[Footnote 75: The dependence of sleeping imagination on emotion of organic origin was long ago clearly seen and set forth by the acute introspective psychologist, Maine de Biran (_Œuvres Inédites_, 'Fondements de la Psychologie,' p. 102).] [Footnote 76: Jastrow (_The Subconscious_, p. 206) relates a similar case observed in a girl student.] [Footnote 77: Herbert Wright, who finds that in children night-terrors are apt to be associated with somnambulism, points out that when the somnambulism replaces the night-terrors it leaves no memory behind (_British Medical Journal_, 19th August 1899, p. 465). An interesting study of movement in normal and morbid sleep has been contributed by Segre ('Contributo alla Conoscenza dei Movimenti del Sonno,' _Archivio di Psichiatria_, 1907, fasc. 1.).] [Footnote 78: This question is, for instance, asked by F. H. Bradley ('On the Failure of Movement in Dreams,' _Mind_, 1894, p. 373). The explanation he prefers is that the dream vision is out of relation to the very dimly conscious actual position of the body, so that the information necessary to complete the idea of the movement is wanting. Only as regards the less complicated movements of lips, tongue, or finger, when the motor idea is in harmony with the actual position of the body movements, does movement take place. We have no means of distinguishing the real world from the world of our vision; 'our images thus move naturally to realise themselves in the world of our real limbs. But the world and its arrangement is for the moment out of connection with our ideas, and hence the attempt at motion for the most part must fail.' It is quite true that this conflict is an important factor in dreaming, but it fails to apply to the large number of movements which we dream of actually doing.] [Footnote 79: The action of some drugs produces a state in this respect resembling that which prevails in dreams. 'Under the influence of a large dose of haschisch,' Professor Stout remarks (_Analytic Psychology_, vol. i. p. 14), 'I found myself totally unable to distinguish between what I actually did and saw, and what I merely thought about.' Not only are the motor and sensory activities relatively dormant, but the central activity is perfectly able, and content, to dispense with their services. 'Thought,' as Jastrow says (_Fact and Fable in Psychology_, p. 386), 'is but more or less successfully suppressed action.']