It has often occurred to myself, in circumstances analogous to the above, when thinking of persons or places at a distance, to see them imaged before me in such vivid relief that I have been startled as if by a morbid hallucination. Once, in passing through my chamber, my attention was so strongly fixed on an absent person that I was not only vividly conscious of his form, but also of his voice and gestures, so that I was amazed by the lively image brought before me. I could adduce other instances from my own experience and that of others to show that in a waking and altogether normal state we may believe in the reality of the image as we do in dreams.
This vivid and momentary realization of images is very common in the lower classes, who often talk to themselves, and use gestures which show that they are conversing at the moment with imaginary persons, who stand before them, as if they were really there, in the same manner as in dreams. Indeed, every one has experienced this phenomenon for himself, especially when strongly excited by anger, sorrow, or hope. If it were possible to reflect on the process of thought at the time we should distinctly understand that we were dreaming while still awake.
The vivid imagination of artists is well known, so that they are able to see and represent things and persons, either in words, with the pencil, or the chisel, just as if they were actually present. The image so vividly realized is a necessary condition of the exercise of their respective arts. When great poets, such as Dante, Ariosto, Milton, and Goethe, conceived and idealized their thoughts with every detail of circumstances, persons, actions, expressions, and movements, no one can deny that the images were vividly present to their minds, and that while in the act of composition these were unconsciously regarded as having a real existence. If these poetic descriptions are presented to the attentive reader in such a vivid form as to transport him into a real world, much more must the authors of these marvellous creations have looked upon them as real at the moment of composition. The impression of truthfulness is indeed produced by the fact that the writers saw these things as though they were real. I speak of states of consciousness, not of reflex observation, of intense moments of sensation and imagination, which are unnoticed by the man who experiences them in his waking moments. Such is the reader of a poem, a romance, or history, the spectator of a picture, who is able for the time to abstract himself from surrounding objects, and who implicitly believes that he sees those places and persons, or whatever the book or painter has described or represented. If suddenly interrupted, he rouses himself, and may be said to awake to the present reality of things, as if startled from a dream.
Wigan relates that a celebrated portrait painter worked with such quickness and facility that he painted more than three hundred portraits in a year. When he was asked the secret of his rapid execution and of the faithfulness of the likeness, he replied, "When any one proposes to have his portrait taken, I look at him attentively for half an hour, while sketching his features on the canvas; I then lay the canvas aside and pursue the same method with another portrait, and so on. When I wish to return to the first, I take his person into my mind and place it before me as distinctly as if he were actually present. I set to work, looking at the sitter from time to time, since I am able to see him whenever I look that way." Talma asserted that when he was on the stage, he was able by mere force of will to transform his audience into skeletons, which affected him with such emotion as to add force and energy to his action. Abercromby speaks of a man who had the faculty of calling up visions with all the vividness of reality whenever he pleased, by strongly fixing his attention on mental conceptions which corresponded to them. Yet he was a sane man, in the prime of life, perfectly intelligent, and versed in practical affairs.
A very slight withdrawal of the attention from surrounding objects is all that is necessary to enable artists and some other persons to call up these images with vivid distinctness, since even in the waking state the image may for the moment appear to be actually before them. Any one might attain to the same power of verification if the transition from the real to the merely ideal image were not in the waking state so instantaneous and easy; whereas in a dream the state of illusion is uninterrupted, and it is physiologically impossible for the mind to pass immediately from the image, which is believed to be real, to the simply representative idea of the thing.
Even in the waking state, the image and representative idea of the thing naturally tend to become, or to appear to be, actual realities, even in a strictly normal condition of mind and body. Nor do they only implicitly tend to become such by the innate impulse of the mind, but they actually become so in fugitive moments of which man is scarcely conscious, and they appear to him exactly as they do in dreams. Hence it follows that there is no hard and fast line between the sleeping and waking states, so far as the nature of images, their source, action, and combinations are concerned, when men are distracted in mind, and the course of their thoughts is not voluntarily directed to some definite object; so that by a psychological process the phenomena of the waking state may be partly transformed into those of dreams. The vivid character of the image, presented to the senses as if actually there, is common to both phenomena. The way in which we begin to dream shows how, owing to our physiological conditions, we pass through regular stages from the waking state into that of sleep.
"Nuovo pensiero dentro a me si mise,
Dal qual più altri nacquero e diversi;
E tanto di uno in altro vaneggiai
Che gli occhi per vaghezza ricopersi,
E il pensamento in sogno trasmutai."[33]
So Dante writes in the "Purgatorio" with deep and subtle truth. Each man can verify for himself the exactness of the great poet's description.
I myself can readily study the phenomena of dreams, since I never sleep without dreaming so vividly that I remember all the circumstances in the morning. I have used all sorts of artifices in order to trace the beginning of sleep and dreams, and always with the same result, so that I am certain of the accuracy of experiments which have been repeated a hundred times. I have examined other persons who have made the same observations, all of whom agree with me.
When repose, the herald of sleep and dreams, begins, my thoughts wander in an irregular and somewhat confused manner. As they are gradually subjected to the associations to which they successively give rise, they are transformed into more vivid images, a vividness which is always in inverse proportion to the attention. This gradually produces the state which has been described by Maury and others as hypnagogic hallucination; that is, the images seem to be real, although the subject is still partly awake, and the voluntary exercise of thought is lost from time to time in this species of incipient chaos. It is at this point that images are really most intense, and that every idea assumes a body and form, every image a reality: finally, when the body and the brain have reached the physiological conditions of sleep, thoughts which had been changed into hypnagogic images in the intermediate stage between sleep and waking, are altogether transformed into the real images of dreams.