You approach a pleasant manor situated on well-cultivated grounds. One man who seems to be in charge approaches you, and you explain your fears about the impending destruction of Islandia.
“I see,” he remarks. “Yes, you’re not the first with those fears. Won’t you follow me?” He takes you into the manor and shows you into a curiously empty room. When he slams the door shut, you turn around in surprise.
“What are you doing?” you demand. “Let me out!”
“You’ll be fine here,” the man says. “You’ll get along just fine with other patients, and the doctors are very nice.”
You get the idea now. “But I am perfectly sane!” you shout.
“Of course,” replies the doctor. “That’s what they all say.”
You languish in captivity all day. You are taken out only once, and when you try to escape you are strapped into a straitjacket. You notice that none of the other patients seem to be confined; in fact, you cannot tell the difference between the doctors and the patients at all!
You overhear two men speaking, one apparently named Valentine and the other Proteus.
“Hey, Valentine!” you call. “What do you know about this guy Proteus?”
“You should call him Doctor Proteus,” Valentine explains. “He is a doctor here.”
“Is that so? Well, Doctor Proteus, what do you know about Valentine here?”
Proteus smiles. “He’s a patient,” he answers. The two men walk off, leaving you in silent contemplation.
The next morning, an Inspector arrives to interview all the mental cases—including you. You explain that you are wrongly imprisoned, but he cuts you off.
“Everybody says that, doesn’t mean a thing. The situation is this: There are doctors in this asylum and there are patients. There are sane people who are 100% accurate in everything they believe—if something is true they know it and believe it—and there insane people who are 100% wrong in everything they believe; that is, anything that is false they will think to be true and vice versa. Everyone around here is honest, so it’s easy to separate the sane from the insane, the doctors from the patients.”
“Do the two always go together?” you ask.
“So far.” He laughs.
“If I could prove to you that there was a case of either an insane doctor or a sane patient, would that clear me?”
The Inspector thinks. “I suppose so. But this better be good…”
How do you argue your way out of the straightjacket? Submit your solution…
