 past and future in the unconscious. So far, I have been sketching some of the principles on which I approached the problem of dreams. For when we want to investigate man's faculty to produce symbols, dreams prove to be the most basic and accessible material for this purpose. The two fundamental points in dealing with dreams are these. First, the dream should be treated as a fact about which one must make no previous assumption except that it somehow makes sense. And second, the dream is a specific expression of the unconscious. One could scarcely put these principles more modestly. No matter how low anyone's opinion of the unconscious may be, he must concede that it is worth investigating. The unconscious is at least on a level with the loves, which after all enjoys the honest interest of the entomologist. If somebody with little experience and knowledge of dreams thinks that dreams are just chaotic occurrences without meaning, he is at liberty to do so. But if one assumes that they are normal events, which is a matter of fact they are, one is bound to consider that they are either causal, that is, that there is a rational cause for their existence, or in a certain way, purposive, or both. Let us now look a little more closely at the ways in which the conscious and unconscious contents of the mind are linked together. Take an example with which everyone is familiar. Suddenly you find you cannot remember what you were going to say next, though a moment ago the thought was perfectly clear. Or perhaps you were about to introduce a friend, and his name escaped you as you were about to utter it. You say you cannot remember. In fact, though, the thought has become unconscious, or at least momentarily separated from consciousness. We find the same phenomenon with our senses. If we listen to a continuous note on the fringe of audibility, the sound seems to stop at regular intervals and then start again. Such oscillations are due to a periodic decrease and increase in one's attention, not to any change in the note. But when something slips out of our consciousness, it does not cease to exist any more than a car that has disappeared round a corner has vanished into thin air. It is simply out of sight. Just as we may later see the car again, so we come across thoughts that were temporarily lost to us. Thus part of the unconscious consists of a multitude of temporarily obscured thoughts, impressions, and images that, in spite of being lost, continue to influence our conscious minds. A man who is distracted or absent-minded will walk across the room to fetch something. He stops, seemingly perplexed. He is forgotten what he was after. His hands grop about among the objects on the table as if he were sleepwalking. He is oblivious of his original purpose, yet he is unconsciously guided by it. Then he realizes what it is that he wants. His unconscious has prompted him. If you observe the behavior of a neurotic person, you can see him doing many things that he appears to be doing consciously and purposefully. Yet if you ask him about them, you will discover that he is either unconscious of them or has something quite different in mind. He hears and does not hear. He sees yet is blind. He knows and is ignorant. Such examples are so common that the specialist soon realizes that unconscious contents of the mind behave as if they were conscious and that you can never be sure in such cases whether thought, speech or action is conscious or not. It is this kind of behavior that makes so many physicians dismiss statements by hysterical patients as utter lies. Such persons certainly produce more untruths than most of us, but lie is scarcely the right word to use. In fact, their mental state causes an uncertainty of behavior because their consciousness is liable to unpredictable eclipse by an interference from the unconscious. Even their skin sensations may reveal similar fluctuations of awareness. At one moment, the hysterical person may feel a needle prick in the arm. At the next, it may pass unnoticed. If his attention can be focused on a certain point, the whole of his body can be completely anesthetized until the tension that causes this blackout of the senses has been relaxed. Sense perception is then immediately restored. All the time, however, he has been unconsciously aware of what was happening. The physician can see this process quite clearly when he hypnotizes such a patient. It is easy to demonstrate that the patient has been aware of every detail. The prick in the arm or the remark made during an eclipse of consciousness can be recalled as accurately as if there had been no anesthesia or forgetfulness. I recall a woman who was once admitted to the clinic in a state of complete stupor. When she recovered consciousness next day, she knew who she was but did not know where she was, how or why she had come there or even the date. Yet after I had hypnotized her, she told me why she had fallen ill, how she had got to the clinic and who had admitted her. All these details could be verified. She was even able to tell the time at which she had been admitted because she had seen a clock in the entrance hall. Under hypnosis, her memory was as clear as if she had been completely conscious all the time. When we discuss such matters, we usually have to draw on evidence supplied by clinical observation. For this reason, many critics assume that the unconscious and all its subtle manifestations belong solely to the sphere of psychopathology. They consider any expression of the unconscious as something neurotic or psychotic, which has nothing to do with a normal mental state. But neurotic phenomena are by no means the products exclusively of disease. They are in fact no more than pathological exaggerations of normal occurrences. It is only because they are exaggerations that they are more obvious than their normal counterparts. Hysterical symptoms can be observed in all normal persons, but they are so slight that they usually pass unnoticed. Forgetting, for instance, is a normal process in which certain conscious ideas lose their specific energy because one's attention has been deflected. When interest turns elsewhere, it leaves in shadow the things with which one was previously concerned, just as a search light lights up a new area by leaving another in darkness. This is unavoidable. For consciousness can keep only a few images in full clarity at one time, and even this clarity fluctuates. But the forgotten ideas have not ceased to exist. Although they cannot be reproduced at will, they are present in a subliminal state, just beyond the threshold of recall, from which they can rise again spontaneously at any time, often after many years of apparently total oblivion. I am speaking here of things we have consciously seen or heard and subsequently forgotten. But we all see, hear, smell, and taste many things without noticing them at the time, either because our attention is deflected or because the stimulus to our senses is too slight to leave a conscious impression. The unconscious, however, has taken note of them, and such subliminal sense perceptions play a significant part in our everyday lives. Without our realizing it, they influenced the way in which we react to both events and people. An example of this that I found particularly revealing was provided by a professor who had been walking in the country with one of his pupils, absorbed in serious conversation. Suddenly he noticed that his thoughts were being interrupted by an unexpected flow of memories from his early childhood. He could not account for this distraction. Nothing in what had been said seemed to have any connection with these memories. On looking back, he saw that he had been walking past a farm when the first of these childhood recollections had surged up in his mind. He suggested to his pupil that they should walk back to the point where the fantasies had begun. Once there, he noticed the smell of geese, and instantly he realized that it was this smell that had touched off the flow of memories. In his youth, he had lived on a farm where geese were kept, and their characteristic smell had left a lasting, though forgotten impression. As he passed the farm on his walk, he had noticed the smell subliminally, and this unconscious perception had called back long forgotten experiences of his childhood. The perception was subliminal because the attention was engaged elsewhere, and the stimulus was not strong enough to deflect it and to reach consciousness directly, yet it had brought up the forgotten memories. Such a cue or trigger effect can explain the onset of neurotic symptoms as well as more benign memories when a sight, smell, or sound recalls a circumstance in the past. A girl, for instance, may be busy in her office, apparently in good health and spirits. A moment later, she develops a blinding headache and shows other signs of distress. Without consciously noticing it, she has heard the foghorn of a distant ship, and this has unconsciously reminded her of an unhappy parting with a lover whom she has been doing her best to forget. Aside from normal forgetting, Freud has described several cases that involve the forgetting of disagreeable memories, memories that one is only too ready to lose. As Nietzsche remarked, where pride is insistent enough, memory prefers to give way. Thus among the lost memories, we encounter not a few that owe their subliminal state and their incapacity to be voluntarily reproduced to their disagreeable and incompatible nature. The psychologist calls these repressed contents. A case in point might be that of a secretary who is jealous of one of her employer's associates. She habitually forgets to invite this person to meetings, though the name is clearly marked on the list she is using. But if challenged on the point, she simply says she forgot or was interrupted. She never admits, not even to herself, the real reason for her omission. Many people mistakenly overestimate the role of willpower and think that nothing can happen to their minds that they do not decide and intend. But one must learn to discriminate carefully between intentional and unintentional contents of the mind. The former are derived from the ego personality. The latter, however, arise from a source that is not identical with the ego, but is its other side. It is this other side that would have made the secretary forget the invitations. There are many reasons why we forget things that we have noticed or experienced, and there are just as many ways in which they may be recalled to mind. An interesting example is that of cryptomnesia or concealed recollection. An author may be writing steadily to a preconceived plan, working out an argument or developing the line of a story when he suddenly runs off at a tangent. Perhaps a fresh idea has occurred to him or a different image or a whole new subplot. If you ask him what prompted the digression, he will not be able to tell you. He may not even have noticed the change, though he has now produced material that is entirely fresh and apparently unknown to him before. Yet it can sometimes be shown convincingly that what he is written bears a striking similarity to the work of another author, a work that he believes he has never seen. I myself found a fascinating example of this in Nietzsche's book Thus Spake Zarathustra, where the author reproduces almost word for word an incident reported in a ship's log for the year 1686. By sheer chance, I had read this Siemens yarn in a book published about 1835, half a century before Nietzsche wrote, and when I found the similar passage in Thus Spake Zarathustra, I was struck by its peculiar style, which was different from Nietzsche's usual language. I was convinced that Nietzsche must also have seen the old book, though he made no reference to it. I wrote to his sister, who was still alive, and she confirmed that she and her brother had in fact read the book together when he was eleven years old. I think from the context it is inconceivable that Nietzsche had any idea that he was plagiarizing this story. I believe that fifty years later it had unexpectedly slipped into focus in his conscious mind. Note, Nietzsche's cryptomnesia is discussed in Jung's on the psychology of so-called occult phenomena in collected works, Volume 1. The relevant passage from the ship's log and the corresponding passage from Nietzsche are as follows. From J. Kernar, Blätter aus Präwurst, Volume 4, page 57, headed an extract of awe-inspiring import, originally 1831 to 37. The four captains and a merchant, Mr. Bell, went ashore on the island of Mount Stromboli to shoot rabbits. At three o'clock they mustered the crew to go aboard, when, to their inexpressible astonishment, they saw two men flying rapidly toward them through the air. One was dressed in black, the other in gray. They came past them very closely, in greatest haste, and to their utmost dismay, descended into the crater of the terrible volcano, Mount Stromboli. They recognized the pair as acquaintances from London. From F. Nietzsche, thus spake Zarathustra, Chapter 40, Great Events, translated by Common, page 180, slightly modified, originally 1883. Now about the time that Zarathustra sojourned on the Haffey Isles, it happened that a ship anchored at the isle on which the smoking mountain stands, and the crew went ashore to shoot rabbits. About the noontide hour, however, when the captain and his men were together again, they suddenly saw a man coming toward them through the air, and the voice said distinctly, It is time. It is highest time. But when the figure drew close to them, flying past quickly like a shadow in the direction of the volcano, they recognized with the greatest dismay that it was Zarathustra. Behold, said the old helmsman, Zarathustra goes down to hell. End of note. In this type of case, there is genuine, if unrealized, recollection. Much the same sort of thing may happen to a musician who has heard a peasant tune or popular song in childhood, and finds it cropping up as the theme of a symphonic movement that he is composing in adult life. An idea or an image has moved back from the unconscious into the conscious mind. What I have so far said about the unconscious is no more than a cursory sketch of the nature and functioning of this complex part of the human psyche. But it should have indicated the kind of subliminal material from which the symbols of our dreams may be spontaneously produced. This subliminal material can consist of all urges, impulses and intentions, all perceptions and intuitions, all rational or irrational thoughts, conclusions, inductions, deductions and premises, and all varieties of feeling. Any or all of these can take the form of partial, temporary, or constant unconsciousness. Such material has mostly become unconscious because in a manner of speaking there is no room for it in the conscious mind. Some of one's thoughts lose their emotional energy and become subliminal. That is to say they no longer receive so much of our conscious attention because they have come to seem uninteresting or irrelevant or because there is some reason why we wish to push them out of sight. It is in fact normal and necessary for us to forget in this fashion in order to make room in our conscious minds for new impressions and ideas. If this did not happen, everything we experienced would remain above the threshold of consciousness and our minds would become impossibly cluttered. This phenomenon is so widely recognized today that most people who know anything about psychology take it for granted. But just as conscious contents can vanish into the unconscious, new contents which have never yet been conscious can arise from it. One may have an inkling, for instance, that something is on the point of breaking into consciousness, that something is in the air or that one smells a rat. The discovery that the unconscious is no mere depository of the past but is also full of germs of future psychic situations and ideas led me to my own new approach to psychology. A great deal of controversial discussion has arisen around this point. But it is a fact that in addition to memories from a long distant conscious past, completely new thoughts and creative ideas can also present themselves from the unconscious, thoughts and ideas that have never been conscious before. They grow up from the dark depths of the mind like a lotus and form a most important part of the subliminal psyche. We find this in everyday life, where dilemmas are sometimes solved by the most surprising new propositions. Many artists, philosophers and even scientists owe some of their best ideas to inspirations that appear suddenly from the unconscious. The ability to reach a rich vein of such material and to translate it effectively into philosophy, literature, music or scientific discovery is one of the hallmarks of what is commonly called genius. We can find clear proof of this fact in the history of science itself. For example, the French mathematician Poincaré and the chemist Cacoulet owed important scientific discoveries as they themselves admit to sudden pictorial revelations from the unconscious. The so-called mystical experience of the French philosopher Descartes involved a similar sudden revelation in which he saw in a flash the order of all sciences. The British author Robert Louis Stevenson had spent years looking for a story that would fit his strong sense of man's double being when the plot of Dr. Jekyll and Mr. Hyde was suddenly revealed to him in a dream. Later I shall describe in more detail how such material arises from the unconscious and I shall examine the form in which it is expressed. At the moment I simply want to point out that the capacity of the human psyche to produce such new material is particularly significant when one is dealing with dream symbolism. For I have found again and again in my professional work that the images and ideas that dreams contain cannot possibly be explained solely in terms of memory. They express new thoughts that have never yet reached the threshold of consciousness.