[17] Maine de Biran, perhaps the earliest accurate introspective observer of dreaming, noted the absence of all voluntary active attention. Beaunis regards attention as possible in dreams, but fails to distinguish between different kinds of attention.
[18] B. Leroy, 'Nature des Hallucinations,' Revue Philosophique, June 1907. As regards the importance of the absence of voluntary attention in the production of visual images, it may be remarked that even the after-image of a bright object in waking life is much more vivid when it occurs in a state of inattention and distraction. I noticed this phenomenon some years ago, especially when studying mescal, and in recent years it has been recorded by J. H. Hyslop (Psychological Review, May 1903).
[19] We must be cautious in assuming that such imagery is purely retinal. Scripture ('Cerebral light,' Studies from the Yale Psychological Laboratory, vol. v., 1899) argues that even the so-called 'retinal light' or 'eigenlicht' is cerebral, not retinal at all, since it is single and not double, and differs from after-images, which are displaced by pressure on eyeball. This view is perhaps too extreme in the opposite direction.
[20] For a full and interesting study of these, see S. J. Franz, 'After-images' (Monograph Supplements to Psychological Review, vol. iii., No. 2, June 1899). He agrees with those who regard after-images as entirely retinal in origin.
[21] See Havelock Ellis, 'A New Artificial Paradise,' Contemporary Review, January 1898; ib. 'Mescal: A Study of a Divine Plant,' Popular Science Monthly, May 1902.
[22] G. E. Partridge, however ('Reverie,' Pedagogical Seminary, April 1898), has investigated hypnagogic phenomena in 826 children. They were asked to describe what they saw at night with closed eyes before falling asleep. Among these children 58·5 per cent. of those aged from thirteen to sixteen saw things at night in this way; of those aged six the proportion was higher, 64·2 per cent. There seemed to be a maximum at about the age of ten, and probably another maximum at a much earlier age. Stars were most frequently mentioned, being spoken of by 151 children, colours by 145, people and faces 77, animals 31, scenes of the day 21, flowers and fruit 18, pictures 15, God and angels 13. Partridge calls these phenomena hypnagogic; while, however, the hypnagogic visions of adults may well be a relic of children's visions, the latter have much greater range and vitality, for they are not confined to the moment before sleep, and the child sometimes has a certain amount of control over them. E. Guyon has studied hypnagogic and allied visions in children in his Paris thesis, Sur les Hallucinations Hypnagogiques, 1903. He believes that children always find them terrifying. That, however, is far from being the case and is merely due to a pre-occupation with morbid cases, which naturally attract most attention. (This is also illustrated by the examples given by Stanley Hall, 'A Study of Fears,' American Journal of Psychology, 1897, pp. 186 et seq.) The visions of the healthy child are not terrifying, and he accepts them in a completely matter-of-course way. He is no more puzzled or troubled by his waking dreams than by his sleeping dreams.
[23] The earliest detailed, though not typical, description of this phenomenon I have met with is by Dr. Simon Forman, the astrologer, in his entertaining Autobiography, written in 1600. He says that, as a child of six, 'So soon as he was always laid down to sleep he should see in visions always many mighty mountains and hills come rolling against him, as though they would overrun him and fall on him and bruise him, yet he got up always to the top of them and with much ado went over them. Then should he see many great waters like to drown him, boiling and raging against him as though they would swallow him up, yet he thought he did overpass them. And these dreams and visions he had every night continually for three or four years' space.' He believed they were sent him by God to signify the troubles of his later years. De Quincey accurately described the phenomenon in 1821, in his Confessions of an English Opium-Eater: 'I know not whether my reader is aware, that many children, perhaps most, have a power of painting, as it were, upon the darkness, all sorts of phantoms: in some, that power is simply a mechanic affection of the eye; others have a voluntary or a semi-voluntary power to dismiss or to summon them, or, as a child once said to me when I questioned him on this matter, "I can tell them to go and they go; but sometimes they come, when I don't tell them to come."' E. H. Clarke (Visions, 1878, pp. 212-216) discussed the ability of children to see visions, and pointed out the element of will in this ability. It seems unusual for auditory impressions to intrude, though J. A. Symonds (biography by Horatio Brown, vol. i. p. 7), in describing his own night-terrors as a child, speaks of phantasmal voices which blended with the caterwauling of cats on the roof.
[24] 'From being long and vehemently attent upon geometrical figures,' Hobbes says after referring to the after-images of the sun (Leviathan, part i., ch. 2), 'a man shall in the dark (though awake) have the images of lines and angles before his eyes: which kind of fancy hath no particular name; as being a thing that doth not commonly fall into men's discourse.'
[25] Baillarger, 'De l'Influence de l'Etat Intermédiaire à la veille et au sommeil sur la Production et la Marche des Hallucinations,' Annales Médico-Psychologiques, vol. v., 1845.
[26] Maury, Le Sommeil et les Rêves, 1861, pp. 50-77. Good descriptions of hypnagogic imagery are given by Greenwood, Imagination and Dreams, pp. 16-18, and Ladd, 'The Psychology of Visual Dreams,' Mind, 1892. See also Sante di Sanctis, I Sogni, pp. 337 et seq.