Infallible lie detector

Yes, it does. If you know I think I’m lying, that is extremely useful information, regardless of whether what I think is true is objectively true or false. And only someone utterly naive, ignorant or self-deluded about human social relations would think otherwise.

We’re talking here about “truth” in the social, not in the scientific, sense.

Trivial.

Significant.

Maybe trivial, but white lies in these situations are the grease that enables the machinery of social interaction to work smoothly.

The “white lies” you refer to are part of courtesy. Any functional society wil have room for such, as part of the lubricant that allows humans-as-moving-parts to come into contact smoothly.

The machine posited in the OP is designed to correct deceptions far less socially or spiritually useful, and far more seriously destructive.

We’re not comparing apples and oranges, we’re comparing apples and money.

“I am a warrior of God, sinner !”

“I intend to save you from the fires of HELL ! !”

I recall that story; I the one that came to my mind was Omnilingual, in which a Trojan in a extremely popular program of that name used subliminal techniques to induce truthfulness in people, no doubt put there by some well intentioned type. The result : The collapse of civilization, or at least of any parts of civilization that had computers. Few and fewer people cooperated, because they couldn’t stand each other without lies; the birth rate crashed both because men and women couldn’t stand each other without lies, and people couldn’t delude themselves about how expensive and tedious raising children was. While a simple lie detector wouldn’t go that far, I do think it would be bad if it became ubiquitous.

I also recall a novel called Barking Dogs, a sort of Dirty Harry-esque take on this with a rogue cop that goes after the bad guys who can’t be touched legally because society is so corrupt. The twist is that he has a “Barking Dog”, a wearable perfect lie detector, so that he can know for a fact if the people he goes after are guilty or not even without a trial. I found it interesting that when he suspected that his wife was having an affair, he turned the thing off, deciding that there were truths he didn’t want to know.

That’s the key failing of the idea, I think - and indeed many hypothetical scenarios such as this - the notion that if something is thus in some cases, it must be thus in all cases, or else it is not so in the first. Not everything can be shoehorned into a single category in all possible cases and variants - so I agree, it would work in some cases, but not by any means all.

To 1 I would answer “It’s a secret; I don’t want to tell you.” I’m not sure if that would tag me as being evasive or not; it really wouldn’t matter, since I’m being open that I don’t feel inclined to reveal my secrets. Remember, this isn’t a truth serum that compells you to talk; it’s a device that reveals if what you do happen to say is a lie or an evasion.

To 2 I would answer, “Nah.” If pressed I could go into more detail, depending on the offense of the hair: “I’m old-fashioned.” “I generally prefer long hair on women.” “I’m no fan of hair dye, you know that.” If the person’s life is crushed by this revelation about my lack of excitement about their hair, then they probably already have learned not to be interested in my opinion long ago.

To 3…well, that’s rather inspecific. But as it happens, in my daily life I don’t white lie. (I do lie, but only to deliberately decieve and manipulate.) It’s surprisingly easy not to waste your dishonesty on trivial matters. Occasionally some people have mild troubles with it (I have a co-worker who is not keen on getting unpeppy answers to “so how’re you doing?”), but for the most part it’s no biggie. And my opinion on clothes is worth something! (Or would be, if I had a lick of fashion sense.)

4 reminds me of Der Trihs’s “interrogated by a frothing Christian” example - which raises the interesting point - this device would be a serious problem in a society run by or substantially populated by evil people. If people were hunting for you, or a specific class of people that included you, and if being found by these people would lead to suffering or misery, then you’d be screwed. Your only hope would be to get out of dodge, and fast.

Fortunately for me, I don’t think the frothing extremist religionists have enough of a grip on the area where I live for this to be a problem for me. Nor do the Nazis, for that matter. So I think I’d be okay.

It looks like the infallible lie detector might be almost upon us now.

It involves questioning a subject while he’s under a magnetic resonance imaging (MRI) machine and checking the on screen reactions of the suspected perp’s or traitor’s brain activity and identifying the responses that involve deceit.

From the link:

Neuroscientist Uses Brain Scan to See Lies Form
From the article:

And even more exciting:

It looks like the system just needs a little tweaking to be made more sensitive, compact and portable and bingo.

The truth shall make us free!