Salsbury's hands were shaking. He was close to the core of his proposition, and he 
didn't know whether Dawson would be fascinated or outraged by it. "For two decades, 
advertisers of consumer products have been able to reach the subconscious minds of 
potential customers by the use of subliminal perception. The ad agencies refer to these 
techniques by several other names. Subliminal reception. Threshold regulation. 
Unconscious perception. Subception. Are you aware of this? Have you heard of it?"
  Still enviably relaxed, Dawson said, "There were several experiments conducted in movie 
theaters-fifteen-maybe twenty years ago. I remember reading about them in the newspapers."
  Salsbury nodded rapidly. "Yes. The first was in 1957."
  "During an ordinary showing of some film, a special message was superimposed on the 
screen. 'You are thirsty,' or something of that sort. It was flashed off and on so fast 
that no one realized it was there. After it had been flashed-what, a thousand times? 
nearly everyone in the theater went to the lobby and bought soft drinks."
  In those first crude experiments, which were carefully regulated by motivation 
researchers, subliminal messages had been delivered to the audience with a tachistoscope, 
a machine patented by a New Orleans company, Precon Process and Equipment Corporation, in 
October of 1962. The tachistoscope was a standard film projector with a high-speed 
shutter. It could flash a message twelve times a minute at of a second. The image 
appeared on the screen for too short a time to be perceived by the conscious mind, but 
the subconscious was fully aware of it. During a six-week test of the tachistoscope, 
forty-five thousand theater-goers were subjected to two messages:
  "Drink Coca-Cola" and "Hungry? Eat Popcorn." The results of these experiments left no 
doubt about the effectiveness of subliminal advertisement. Popcorn sales rose sixty 
percent, and Coco-Cola sales rose nearly twenty percent.
  The subliminals apparently had influenced people to buy these products even though they 
were not hungry or thirsty.
  "You see," Salsbury said, "the subconscious mind believes everything it is told. Even 
though it constructs behavioral sets based on the information it receives, and although 
those sets guide the conscious mind-it can't distinguish between truth and falsehood! The 
behavior that it programs into the conscious mind is often based on misconceptions."
  "But if that were correct, we'd all behave irrationally."
  "And we all do," Salsbury said, "in one way or another. Don't forget, the subconscious 
doesn't always construct programs based on wrong-headed ideas. Just sometimes. This 
explains why intelligent men, paragons of reason in most things, harbor at least a few 
irrational attitudes." Like your religious fanaticism, he thought. He said: "Racial and 
religious bigotry, for instance. Xenophobia, claustrophobia, acrophobia . . . If a man 
can be made to analyze one of these fears on a conscious level, he'll reject it. But the 
conscious resists analysis. Meanwhile, the inner half of the mind continues to misguide 
the outer half."
  "These messages on the movie screen-the conscious mind wasn't aware of them; therefore, 
it couldn't reject them."
  Salsbury sighed. "Yes. That's the essence of it. The subconscious saw the messages and 
caused the outer mind to act on them."
  Dawson was growing more interested by the minute. "But why did the subliminals sell 
more popcorn than soda?"
  "The first message-'Drink Coca-Cola'-was a declarative sentence," Salsbury said, "a 
direct order. Sometimes the subconscious obeys an order that's delivered subliminally-and 
sometimes it doesn't."
  "Why is that?"
  Salsbury shrugged. "We don't know. But you see, the second subliminal was not entirely 
a direct order. It was more sophisticated. It began with a question: 'Hungry?' The 
question was designed to cause anxiety in the subconscious. It helped to generate a need. 
It established a 'motivational equation.' The need, the anxiety, is on the left side of 
the equals sign. To fill the right side, to balance the equation, the subconscious 
programs the conscious to buy the popcorn. One side cancels out the other. The buying of 
the popcorn cancels out the anxiety."
  "The method is similar to posthypnotic suggestion. But I've. heard that a man can't be 
hypnotized and made to do something he finds morally unacceptable. In other words, if he 
isn't a killer by nature, he can't be made to kill while under hypnosis."
  "That's not true," Salsbury said. "Anyone can be made to do anything under hypnosis. 
The inner mind can be manipulated so easily. . . For example, if I hypnotized you and 
told you to kill your wife, you wouldn't obey me."
  "Of course I wouldn't!" Dawson said indignantly.
  "You love your wife."
  "I certainly do!"
  "You have no reason to kill her."
  "None whatsoever."
  Judging by Dawson's emphatic denials, Salsbury thought the man's subconscious must be 
brimming with repressed hostility toward his God-fearing, church-loving wife. He didn't 
dare say as much. Dawson would have denied it-and might have tossed him out of the 
office. "However, if I hypnotized you and told
  you that your wife was having an affair with your best friend and that she was plotting 
to kill you in order to inherit your estate, you would believe me and-"
  "I would not. Julia would be incapable of such a thing."
  Salsbury nodded patiently. "Your conscious mind would reject my story. It can reason. 
But after I'd hypnotized you, I'd be speaking to your subconscious-which can't 
distinguish between lies and truth."
  "Ah. I see."
  "Your subconscious won't act on a direct order to kill because a direct order doesn't 
establish a motivational equation. But it will believe my warning that she intends to 
kill you. And so believing, it will construct a new behavioral set based on the lies-and 
it will program your conscious mind for murder. Picture the equation, Leonard. On the 
left of the equals sign there is anxiety generated by the 'knowledge' that your wife 
intends to do away with you. On the right side, to balance the equation, to banish the 
anxiety, you need the death of your wife. If your subconscious was convinced that she was 
going to kill you in your sleep tonight, it would cause you to murder her before you ever 
went to bed."
  "Why wouldn't I just go to the police?"
  Smiling, more sure of himself than he had been when he entered the office, Salsbury 
said, "The hypnotist could guard against that by telling your subconscious that your wife 
would make it look like an accident, that she was so clever the police would never prove 
anything against her."
  Raising one hand, Dawson waved at the air as if he were shooing away flies. "This is 
all very interesting," he said in a slightly bored tone of voice. "But it seems academic 
to me."
  Ogden's self-confidence was fragile. He began to tremble again. "Academic?"
  "Subliminal advertising has been outlawed. There was quite a to-do at the time."
  "Oh, yes," Salsbury said, relieved. "There were hundreds of newspaper and magazine 
editorials. Newsday called it the most alarming invention since the atomic bomb. The 
Saturday Re-