In a footnote appended to the 1919 edition of his book, The Interpretation of Dreams, Sigmund Freud called attention to the work of Dr. Poetzl, an Austrian neu­rologist, who had recently published a paper de­scribing his experiments with the tachistoscope. (The tachistoscope is an instrument that comes in two forms — a viewing box, into which the subject looks at an image that is exposed for a small fraction of a second; a magic lantern with a high-speed shutter, capable of projecting an image very briefly upon a screen.) In these experiments Poetzl required the sub­jects to make a drawing of what they had consciously noted of a picture exposed to their view in a tachisto­scope. . . . He then turned his attention to the dreams dreamed by the subjects during the following night and required them once more to make drawings of appropriate portions of these dreams. It was shown unmistakably that those details of the exposed picture which had not been noted by the subject provided ma­terial for the construction of the dream."

With various modifications and refinements Poetzl's experiments have been repeated several times, most recently by Dr. Charles Fisher, who has contributed three excellent papers on the subject of dreams and "preconscious perception" to the Journal of the Ameri­can Psychoanalytic Association. Meanwhile the academic psychologists have not been idle. Confirming Poetzl's findings, their studies have shown that people actually see and hear a great deal more than they consciously know they see and hear, and that what they see and hear without knowing it is recorded by the subconscious mind and may affect their conscious thoughts, feelings and behavior.

Pure science does not remain pure indefinitely. Sooner or later it is apt to turn into applied science and finally into technology. Theory modulates into in­dustrial practice, knowledge becomes power, formulas and laboratory experiments undergo a metamorphosis, and emerge as the H-bomb. In the present case, Poetzl's nice little piece of pure science, and all the other nice little pieces of pure science in the field of preconscious perception, retained their pristine purity for a surprisingly long time. Then, in the early au­tumn of 1957, exactly forty years after the publication of Poetzl's original paper, it was announced that their purity was a thing of the past; they had been applied, they had entered the realm of technology. The an­nouncement made a considerable stir, and was talked and written about all over the civilized world. And no wonder; for the new technique of "subliminal projec­tion," as it was called, was intimately associated with mass entertainment, and in the life of civilized human beings mass entertainment now plays a part compara­ble to that played in the Middle Ages by religion. Our epoch has been given many nicknames — the Age of Anxiety, the Atomic Age, the Space Age. It might, with equally good reason, be called the Age of Televi­sion Addiction, the Age of Soap Opera, the Age of the Disk Jockey. In such an age the announcement that Poetzl's pure science had been applied in the form of a technique of subliminal projection could not fail to arouse the most intense interest among the world's mass entertainees. For the new technique was aimed directly at them, and its purpose was to manipulate their minds without their being aware of what was being done to them. By means of specially designed tachistoscopes words or images were to be flashed for a millisecond or less upon the screens of television sets and motion picture theaters during (not before or after) the program. "Drink Coca-Cola" or "Light up a Camel" would be superimposed upon the lovers' em­brace, the tears of the broken-hearted mother, and the optic nerves of the viewers would record these secret messages, their subconscious minds would respond to them and in due course they would consciously feel a craving for soda pop and tobacco. And meanwhile other secret messages would be whispered too softly, or squeaked too shrilly, for conscious hearing. Con­sciously the listener might be paying attention to some phrase as "Darling, I love you"; but subliminally, be­neath the threshold of awareness, his incredibly sensi­tive ears and his subconscious mind would be taking in the latest good news about deodorants and laxatives.

Does this kind of commercial propaganda really work? The evidence produced by the commercial firm that first unveiled a technique for subliminal pro­jection was vague and, from a scientific point of view, very unsatisfactory. Repeated at regular inter­vals during the showing of a picture in a movie theater, the command to buy more popcorn was said to have resulted in a 50 per cent increase in popcorn sales during the intermission. But a single experiment proves very little. Moreover, this particular experiment was poorly set up. There were no controls and no at­tempt was made to allow for the many variables that undoubtedly affect the consumption of popcorn by a theater audience. And anyhow was this the most effec­tive way of applying the knowledge accumulated over the years by the scientific investigators of subcon­scious perception? Was it intrinsically probable that, by merely flashing the name of a product and a com­mand to buy it, you would be able to break down sales resistance and recruit new customers? The answer to both these questions is pretty obviously in the nega­tive. But this does not mean, of course, that the findings of the neurologists and psychologists are with­out any practical importance. Skilfully applied, Poetzl's nice little piece of pure science might well become a powerful instrument for the manipulation of unsuspecting minds.

For a few suggestive hints let us now turn from the popcorn vendors to those who, with less noise but more imagination and better methods, have been experiment­ing in the same field. In Britain, where the process of manipulating minds below the level of consciousness is known as "strobonic injection," investigators have stressed the practical importance of creating the right psychological conditions for subconscious persuasion. A suggestion above the threshold of awareness is more likely to take effect when the recipient is in a light hypnotic trance, under the influence of certain drugs, or has been debilitated by illness, starvation, or any kind of physical or emotional stress. But what is true for suggestions above the threshold of consciousness is also true for suggestions beneath that threshold. In a word, the lower the level of a person's psychological resistance, the greater will be the effectiveness of strobonically injected suggestions. The scientific dictator of tomorrow will set up his whispering machines and subliminal projectors in schools and hospitals (chil­dren and the sick are highly suggestible), and in all public places where audiences can be given a preliminary softening up by suggestibility-increasing oratory or rituals.

From the conditions under which we may expect subliminal suggestion to be effective we now pass to the suggestions themselves. In what terms should the propagandist address himself to his victims' subcon­scious minds? Direct commands ("Buy popcorn" or "Vote for Jones") and unqualified statements ("Social­ism stinks" or "X's toothpaste cures halitosis") are likely to take effect only upon those minds that are already partial to Jones and popcorn, already alive to the dangers of body odors and the public ownership of the means of production. But to strengthen existing faith is not enough; the propagandist, if he is worth his salt, must create new faith, must know how to bring the indifferent and the undecided over to his side, must be able to mollify and perhaps even convert the hostile. To subliminal assertion and command he knows that he must add subliminal persuasion.

Above the threshold of awareness, one of the most effective methods of non-rational persuasion is what may be called persuasion-by-association. The propagan­dist arbitrarily associates his chosen product, candi­date or cause with some idea, some image of a person or thing which most people, in a given culture, unquestioningly regard as good. Thus, in a selling campaign female beauty may be arbitrarily associated with any­thing from a bulldozer to a diuretic; in a political campaign patriotism may be associated with any cause from apartheid to integration, and with any kind of person, from a Mahatma Gandhi to a Senator McCar­thy. Years ago, in Central America, I observed an example of persuasion-by-association which filled me with an appalled admiration for the men who had de­vised it. In the mountains of Guatemala the only im­ported art works are the colored calendars distributed free of charge by the foreign companies whose prod­ucts are sold to the Indians. The American calendars showed pictures of dogs, of landscapes, of young women in a state of partial nudity. But to the Indian dogs are merely utilitarian objects, landscapes are what he sees only too much of, every day of his life, and half-naked blondes are uninteresting, perhaps a little repulsive. American calendars were, in conse­quence, far less popular than German calendars; for the German advertisers had taken the trouble to find out what the Indians valued and were interested in. I remember in particular one masterpiece of commercial propaganda. It was a calendar put out by a manufac­turer of aspirin. At the bottom of the picture one saw the familiar trademark on the familiar bottle of white tablets. Above it were no snow scenes or autumnal woods, no cocker spaniels or bosomy chorus girls. No — the wily Germans had associated their pain-relievers with a brightly colored and extremely lifelike picture of the Holy Trinity sitting on a cumulus cloud and surrounded by St. Joseph, the Virgin Mary, as­sorted saints and a large number of angels. The mirac­ulous virtues of acetyl salicylic acid were thus guaranteed, in the Indians' simple and deeply religious minds, by God the Father and the entire heavenly host.