What about that one circle?

An example of bad reasoning:

"Science has explained most instances of X. Many turned out to be hoaxes. Others had completely natural explanations. But what about the unexplained instances of X? You can't explain them all away!"

If we were playing "Name That Fallacy", I would call this "remembering the hits, and forgetting the misses". But the interesting thing is that the argument acknowledges that there have been plenty of misses, as if acknowledging them would make them go away.

The first concrete example I can think of are crop circles.

Image taken from CircleMakers

Crop circles are a phenomenon that became popular in the 1980s. At first, they were simple circles, but in more recent times, much more complicated patterns have appeared like the one above. It's practically an art form nowadays. I think they look cool, don't you?

According to the mythology, crop circles are created by UFOs, which are always saucer shaped, of course. The UFOs land on a crop and make a circle. There were other theories too, such as whirlwinds or other weather. Now, I would have looked at this and immediately thought that they were man-made. Of course hindsight's 20/20 and I'm too young to understand the 1980s mindset. In any case, there's little point worrying about back then, because the current evidence is very clear. In 1991, two men confessed to making some of the earliest crop circles in England. Well, perhaps "confession" is the wrong word--more like letting the rest of us in on the joke. One of them is interviewed here (god I love this interview).

If that weren't enough, there's even a website "CircleMakers" for people who make these crop circles. Oh look, there's even a field guide. You could be making "unfakeable" crop circles in no time!

Anyways, while I'm sure this evidence convinces most people, there still exist UFOlogists who claim that at least some, if not all crop circles are made by UFOs. You see, even though some of the circles are explained by pranksters, this small group of people couldn't possibly have made every single pattern in the entire world. And even if there were enough circle makers, there exist some circles which are supposedly too complicated to be made by dedicated pranksters.

You can easily see the problem with this reasoning. We already have a sufficient explanation. Adding a second one is just unnecessary, and unlikely to be true. For every circle maker that has confessed, there are going to be other circle makers who chose not to. Just because not every circle has a known creator does not mean that our explanation is insufficient.

Going back to my main point, this is because our investigative ability is limited. We cannot thoroughly investigate every single instance of a phenomenon. Sometimes there are things that just make full investigation too difficult to be feasible. Sometimes there is simply no budget for it. Sometimes all evidence has already disappeared, lost to entropy, leaving the phenomenon permanently unexplained. Sometimes an investigation will even show a false positive, for a variety of reasons. For example, some people heard strange sounds at night which they thought were related to crop circles. Further investigation determined that it was a kind of bird, but what might we have thought if no one had ever figured it out?

But this is not to say that scientific investigation is useless. If done correctly, by the scientific method, tests will correctly discern truth most of the time, if it manages to discern anything at all. But if you ignore most of the results just to look at the few unexplained cases, you've just done away with any validity your analysis might have had. Sometimes, those few unexplained cases are indicative of a new paradigm, but more often than not, they're related to our limited methodology. We need a more compelling argument than the existence of a few unsolved cases.