I was recently working my way through a book on philosophy when I ran across an old intellectual exercise that is worth considering. As I understand it, this problem has been around since the early days of Greek philosophy and it is still used as a "stumper" sort of question that can be used to create lively debate between high school students when the teacher shows up to work hung over. The particular problem I am referring to is the following:
If I say, "I am a liar," should you believe me?
Of course, no self-respecting philosopher would phrase the question in such a way, since that would force the student to think of the philosopher as a liar. Philosophers don't like to be thought of as liars, they like to be thought of as people who speak the truth, or Truth, depending on their self-confidence. But, since I and self-respect (to say nothing of self-confidence) are not on speaking terms, we will continue with my original phrasing.
As you have probably determined by now, the problem is rather complex, since any attempt to fix the answer makes the answer change. If I truly am a liar, then I told the truth, making me not a liar. But if I am not a liar, then I have lied when I said I was a liar, making me a liar. But since I have now lied about being a liar, and the statement is false, I am a liar, making the statement true, which makes me a truth teller in this particular instance, making the statement false, which makes the statement true, et cetera, et cetera, et cetera.
One might call this an example of Douglas Adams' concept of recipriversexclusion -- something that can only equal something other than itself. While this is very useful for Bistromathics, it is also very useful for our particular concerns at present. Or, to get all mathematical, the problem boils down to:
A = ¬A
At least it does in theory. Technically, you could construct an explanation of the problem such that it can be made correct. For instance, one does not need to lie all the time in order to be a liar. Which is fact based, but easily worked around; I change the phrase to "I always lie," I tell it to someone I've never met before, and we return to the point of the exercise.
The interesting fact about this nonsense is that the perception of a thing changes the way it should be perceived and, in fact, changes the truth. By seeing the statement as true, it becomes false, and by seeing it as false, it becomes true. And attempting to fix it as an absolute is impossible, because its value cannot be in anything other than constant flux.
This is the part where I explain how this is related to quantum mechanics. However, this has nothing to do with quantum mechanics at all; though it was nice that you thought you were going to learn something important. But you really need to lower your expectations.
However, this exercise is very useful when observing the essentially mutable nature of things like art and politics. The mechanisms could be said to be more involved, but they still boil down to a similar equation -- the more one thing becomes true, the more it becomes false. What happens when the new style becomes the old style? What happens when the revolution comes to power and becomes the status quo? Likewise, what happens when out-of-date becomes classic? And what happens when the stodgy become wise?
What this boils down to is the idea that time makes fools and prophets of us all. By being wrong now, we will be right later. Well, to a certain degree. By being perceived to be someone who is wrong now and right later, we create a situation where the person will actually be wrong later because everyone thought the person who made the statement was right, precisely because they were wrong in the present and would be right later. This is why forecasting the distant future is such a dodgy business and should usually be left to seers, psychics, astrologers and the insane.
For those who follow the latest developments in ancient mythology, this makes the myth of Cassandra perfectly understandable -- if anybody believed her when she forecast doom, people would do something about it and there would not be doom on the horizon. Then she would just be wrong and wouldn't have the gift of prophecy at all.
A very good example of a practical explanation of how this works is the Year 2000 Problem. You remember -- it was that tempest in a teacup where the world's computers were supposed to melt down because the computers were going to think it was 1900 rather than 2000 when the clock struck midnight on December 31, 1999. Everyone wondered what the fuss was about when nothing happened. But one could argue that nothing happened because there was a tremendous fuss about it and people worked to avert the problem. Y2K worries = Nothing to worry about on Y2K.
By the way, perhaps you are wondering what my opinion is on a more real issue like, for instance, global warming. That's nice that you should ask. Clearly, you are not paying attention.
The wonderful thing about this is that this concept gives purpose to the doommongers in the world. After all, these people are very useful. They are the ones who cry about how everything is going to hell in a handbasket and everything is falling apart and the country is falling into ruin and autocracy and the environment is collapsing and American Idol is going to get nothing but mid-level karaoke acts to sing on their show. The last is, of course, already true, so there is no point in worrying about it. However, the other issues are not going to happen. Why? Because the fear of them mobilizes people to prevent them from happening.
Have you noticed that the only real calamities are the ones that were unexpected? Nobody expected planes to be hijacked and crashed into large buildings, nobody expected JFK to get shot, nobody expected Pearl Harbor to be bombed. These were disasters because they did not fit in with the way that people thought of the world. One cannot assume that these things would not happen, because it never occurred to most people to even think about them as possibilities. It is often said that you can't, by definition, expect the unexpected -- though it's really rather a shame that nobody believes it.
Why were so many people killed by the Indonesian tsunami? Because nobody ever thought to put together a tsunami warning system because no one ever thought to put a warning system together, since there weren't that many killer tsunamis in that part of the world; so when geologists saw the earthquake, they couldn't warn people who would expect a warning for something like a tsunami -- since there would surely be a system in place to warn people about a gigantic tsunami approaching a huge country like Indonesia.
Why were so many people killed by Hurricane Katrina? Because a bunch of people thought that the levees would hold back the water like they always do, despite the fact that the levees were in bad shape because there was never a reason to worry about them because the levees always held back the water.
All this empty opinion from a philosophical exercise with no answer. Yet you're still reading. Which forces me to assume that you are expecting something more from this essay than just the idea that people only prepare for disasters that have already happened. Well, you're right. Sort of.
Now then, what's the problem with this extrapolation of practical fortune telling from an exceptionally simple philosophical question? That, of course, is the converse statement: "I am not a liar."
The statement "I am a liar" does have some observable truth value simply by the fact that one can make some sort of inference from the statement in and of itself. However, the statement "I am not a liar" has absolutely nothing can be inferred from it. This is because both a liar and a non-liar would say exactly the same thing, making the statement itself completely uninformative and, for the purpose of logical inference, useless.
For all we know, nothing bad would have happened on Y2K if nothing had been done, JFK would have been killed a week later anyway (Damn you, Siegenthaler!), and earth would not have been invaded by man-eating blancmanges from Planet Skyron in the galaxy of Andromeda. The end result may have been immutable, just as a liar and a non-liar would both be consistent with their characters by saying, "I am not a liar."
Sometimes, the inevitable is simply that: inevitable. And, sometimes a non-issue is a non-issue no matter how little worrying we put into it. It's too bad that there is usually no way to tell the difference. Because we can worry all we like, but there is just no way to stop the sun from setting every night. And it keeps rising every morning, despite all of our best efforts. And the fact that this is often the case completely invalidates everything I have said to this point. So don't you feel better for having read it?