Friday, May 12, 2006

"The innocent have nothing to fear"

Julian Baggini explains the logical fallacy of "the innocent have nothing to fear" argument.

The argument is a particular species of false dichotomy. You are presented with a simple either/or choice. Either you’re guilty, and so should be exposed; or you are innocent, in which case nothing will be exposed, and so you have nothing to worry about. Either way, you have no legitimate reason to be concerned. Like all false dichotomies, the problem is that there is at least one more option than the two offered in the either/or choice.

In the case of “The innocent have nothing to fear” argument, the key point is usually that our objections have nothing to do with our guilt or innocence, but with our right to privacy. We don’t want to be scrutinised at every turn because constant scrutiny is an intrusion into our privacy. Consider, for example, that what we get up to in our bedrooms may be nothing to be ashamed of, but most of us still wouldn’t want others to stand around and watch. Potential voyeurs would not have a very strong case if they simply said, “Why not let us look? Doing something you shouldn’t be?” “The innocent have nothing to fear” is therefore usually an example of a red herring: the fact that we are not doing anything wrong is beside the point.


flitworth said...

Thanks for pointing this out, H.G. I also think the rationale “the innocent have nothing to fear” plays into the us-versus-them mind-set, and of course, we’re always “us” and naturally always innocent. So those others, who are “them” and guilty, too, since they're acting like they have something to hide, are only going to get what they deserve. We can stay safe and pristine on the other side of the line. It’s a very good mechanism for dividing and then an excellent excuse for “us” to feel like it's OK to keep our eyes and mouths shut.

Psyberian said...

As Marilyn vos Savant pointed out in one of her articles, privacy is an end in itself - it has no bearing on right or wrong, guilty or innocent. Even a child learns to appreciate privacy at an early age, so it is something we all value.
I'm glad you made that clear.

Hume's Ghost said...

You know, I've seen vos Savant quoted over and over again by one of my favorite writers, Cliff Pickover, but I've never actually read anything she's written.

Psyberian said...

Actually, the only thing I've read by vos Savant is in her weekly newspaper columns answering questions from readers.

BTW, the controversial answer she gave to the “Monty Hall problem” is interesting: I don't get how the odds change just by changing your choice - but I'm no odds wiz.

Hume's Ghost said...

Thank you. That's the first I'd heard of that problem, and I can see why so many people thought Savant was wrong at first. It took me a minute to wrap my brain around the logic, but it does make sense.

Look at it this way, you start out with the odds being 1 in 3 that you have chosen correctly, meaning that there is a 66% chance your original choice is wrong (and that there is thus a 66% chance that the prize is in one of the two remaining doors.)

After the door with the goat is eliminated, you now know that there is a 66% chance that the second door is the correct choice.

This is where most people will make the error. They will assume that there is now a 50/50 chance that either door has the prize, but they forget that there was a 66% chance that their original choice was wrong.

When you switch doors, you are betting (properly) that your first choice was wrong.

Psyberian said...

Your explanation is a good one and I can see that. But here is what I keep coming back to when thinking of the odds: after one of the other doors has been eliminated, regardless of which door you picked at first, there is still a 50/50 chance that your original choice is correct, isn’t it? How do the powers that be know when we’ve changed our choice in that circumstance? Flipping a coin would be less successful in that circumstance too since it would lead to the original choice half of the time, wouldn’t it? Or maybe I just think too much…

Hume's Ghost said...

there is still a 50/50 chance that your original choice is correct, isn’t it?

No, there is not. It seems counter-intuitive, but that's probably indicative of how our brains are wired, I suspect. The 50/50 chance is illusory: the odds would be 50/50 if you had not made your original choice. Its actually the reverse of what you're thinking, if the odds were 50/50, the powers that be would be retroactively changing the odds on your first choice.

See if this helps:
Choose Door 1
Door 1 - 33% Door 2 - 33% Door 3 - 33% = Door 1 - 33% (Door 2 or Door 3) - 66%

After Door 3 is eliminated
Door 1 - 33% (Door 2, but not Door 3) - 66%

Once you make your first choice there is a 66% chance it was wrong. When the next door is eliminated it means there is only a 33% chance the second door is wrong. This is because the odds say that your first choice will usually be wrong. Over a series of trials its going to turn out that the second door has the prize.

Think of this: you reach into a jar with 2 red marbles and 1 green, blindfolded. I then remove a red marble from the jar (regardless of what you grab at first, there will be at least one red marble remaining.) Again, you have a choice - keep the marble in your hand or switch. The odds say you picked a red marble on your first pick, so it would be statistically wise to switch. Same principle as with the doors.

Flipping the coin would be less successful because you would pick the statistically less likely choice 50% of the time.