In Chain of Command, Part II Picard is tortured by Madred, a Cardasian who tries to force Picard to tell him there are 5 lights, when in fact the real number is four. He could have used any other method to break Picard’s will, but why four lights?
Is this a military training tactic, to instill obedience into troops? Or is it something else?
The torture scene in this episode is nearly verbatim from Nineteen Eighty-Four's "2 + 2 = 5". In the novel, the slogan is a primary example of doublethink, the ability of the totalitarian ruling party to exert such control they can even make people admit obvious falsehoods. Sensory evidence - or in the case of the novel, analytic truth - is internalized as insanity, and external statements are internalized as true, even when the subject isn't actually insane. The captors are showing their strength not just by forcing the captive, but by forcing reality itself.
At the end of the novel, the main character is being tortured into admitting that 2 + 2 is in fact 5. Unlike Picard, he does break - he admits to seeing five fingers even though he really only sees four. This begins a downward slide into compliance with the state.
Orwell invented this kind of situation as an allegory for the propaganda of the Nazi party, although he also applied it to Communism in Russia.
In the end the Party would announce that two and two made five, and you would have to believe it. It was inevitable that they should make that claim sooner or later: the logic of their position demanded it. Not merely the validity of experience, but the very existence of external reality, was tacitly denied by their philosophy. The heresy of heresies was common sense. And what was terrifying was not that they would kill you for thinking otherwise, but that they might be right. For, after all, how do we know that two and two make four? Or that the force of gravity works? Or that the past is unchangeable? If both the past and the external world exist only in the mind, and if the mind itself is controllable—what then?
Once that level of control is reached - when you can convince someone that your statements have primacy over their mental processes - you can make them do anything.
The point of this was simply to "break" Picard with a meaningless, symbolic victory. Agreeing that there are five lights instead of four is, on the surface, completely harmless, unlike revealing important tactical information from the Federation or conceding an ideological point.
However, Picard knows that once he gives any ground to Madred, it's only a matter of time before he gives up anything. After that, anything is fair game.
This is why, even after Picard is rescued, Madred still makes a last-ditch effort to force Picard to agree that there are five lights. He knows that if he has this, he will always be certain that his was the stronger will and that he could have eventually worn Picard down and gotten whatever information he wanted.
Why the lights?
It's like the "third degree" in old cop movies. In those, often someone was forced to sit in a dark room and made to stare at a bright light. That would blind them so they couldn't see faces, only silhouettes of people. It depersonalizes everyone else and makes it harder for the victim to identify with anyone and it makes them even more alienated from everyone else.
While Madred wasn't using the lights in the same way, the likelihood is that they were hot and bright, both of which would be hard on Picard. Every time Madred made him look at the lights, he would be temporarily blinded and would feel pain from looking into the lights. While that's not a major source of pain, it carries the message that Madred is in control and that even on the small things, he intends to not give Picard a break.
While he could have used anything, like the color of a wall or the shape of his desk, by using lights, he was able to create more confusion by blinding Picard (at least temporarily) and causing him discomfort every time he made Picard look at the lights. It was just another way to get under Picard's skin, and it was more effective than using the color of something or the shape of his desk.
As to the number, he was likely just working with the lights that he had in the room. Likely any number of lights from two to four would work. It's tough for someone to see one light and say it's two, and once you start with five lights, it's harder to count them and easier to confuse five with six. But with two, three, or four lights, even when Picard was drained from torture, he could still count four and know there were four, even if he gave in.
It's a tactic to force Picard to accept what Madred tells him is reality rather than what his senses tell him is reality. (In short, to break Picard to Madred's will.) If Picard breaks willingly, then he has given in and succumbed in the contest of wills.
However, in torture to extract information or to instill obedience, quite often victims actually do come to no longer see reality, but rather what is being told to them is reality. In order to stop the pain, the mind does what it needs to to protect the victim.
Likely, this was an example of both, as PIcard's "admission" that there are five lights would indicate either that he is willing to comply to stop the torture (a small victory for Madred) or that his mind has broken and he actually sees the five lights (a greater victory)
In the end, Picard admits that he did see five lights instead of four, indicating that Madred succeeded in the latter end, where Picard's indomitable will kept him from admitting it. http://en.memory-alpha.org/wiki/Chain_of_Command,_Part_II_%28episode%29
You could also ask why Madred just didn't turn on the pain device and not turn it off until Picard told him what he wanted. The answer is, as alluded to in the episode, physical torture is a terrible way of getting information because after awhile the victim will say whatever you want just to make it stop and said information will likely be made up or false. Psychological torture, like forcing someone to admit something that they know is false is true, is much more effective. This is why the episode is so good, it is a very accurate portrayal of actual torture. Also, Picard employs a common strategy taught to resist torture: developing pity for the torturer ("you can't hurt me you are still that small boy"). By doing that you make it less likely that they will break you psychologically, because once that happens you can be easily manipulated into revealing other information. Hence why Madred focused so much on the lights and not on the information he wanted because if he could get Picard to admit there were five lights he could get him to do anything.
Coercion is a basic tactic in psychological operations. Once you have coerced your victim to do something simple like state a known falsehood, the door is opened to coerce them into revealing or doing much more important things.
Khan in Star Trek II and Nero both used insect-like creatures that induced susceptibility to suggestion in order to coerce their victims.
The "4 lights" shtick is directly cribbed from the "4 fingers" scene in George Orwell's "1984". In 1984, the torturer makes it clear that the point is not to get the victim to agree that there are 5 lights.
In fact, at one point the victim, Winston Smith, readily agrees with his torturer, only to be tortured some more. "You don't get it," says the torturer. "You're lying to me. You still see 4 lights and are merely saying there are 5 so that I will stop torturing you. That's not enough. The point here is not to get you to parrot whatever I want you to say. The point is that I will keep torturing you until you really see five lights."
This goes beyond torturing for information, or torturing to achieve compliance. Nor is it torturing to drive a person insane. It is even beyond merely breaking the subject's will. Read "1984". At the end of the novel, the hero, Winston Smith, is happy that at last he has learned to love Big Brother.
I kind of liked the idea that Madred WAS the fifth light. While I can't deny the 1984 reference, because that's pretty epic, I think the reasoning for using light, rather than fingers, allowed Madred to assert himself as a god-like figure to Picard to tell him that he had absolute control over his fate. If Picard admitted there were 5 lights, he would be admitting that Madred was the fifth light. Food for thought.
Madred and Picard waged a war against each other. To use a historical analogy, the "five" lights were like Caesar's river Rubicon. Totally meaningless in its own right, but to both parties involved it symbolized an irreversible change of the situation.
