"The world is less miraculous than most will ever believe;
yet more wonderful than they will ever know."
There have always been scientists whose interests stretched beyond their laboratory. I am not the first to have thought about Bigfoot or the Bermuda Triangle.
The basic rules of science are that belief should be proportional to the quality of the evidence. And, belief must change as new evidence is found. As Feynman said, there is nothing that a scientist is completely certain of. There is no telling what I will have to unlearn tomorrow.
A lot of my training deals with the evaluation of evidence. As a historian, I've heard innumerable stories of people who accepted new ideas too readily, or held on to old ideas too long. We now have standards and rules that aim to prevent these embarrassments.
For example, one rule is that anecdotal evidence doesn't cut it. Another rule is that a whole pile of bad evidence is still just bad evidence.
A big rule is that extraordinary claims require extraordinary evidence. Let me give an example.
Suppose someone says "I have a cubic foot of salt in my lab." I wouldn't bat an eye.
Suppose someone says "I have a cubic foot of platinum in my lab." I'd probably ask what he needed that much for. I'd probably ask if he was sure about the quantity. But if his answers were good, I'd accept it.
Suppose someone says "I have a cubic foot of plutonium in my lab." Only an extraordinary lab would have something that expensive and dangerous and useless. (And it's illegal for most people to own.) I would require quite a lot of convincing. Wouldn't you?
How does this apply in the real world? Well, the Loch Ness Monster is an extraordinary claim. A skeptic doesn't believe that a blurry photo is enough evidence. After all, the photo can be a mistake or a hoax. And sure enough, several Loch Ness hoaxsters have recently 'fessed up.
Why does skepticism matter? Because false beliefs harm people, and cost them money, and lead them to hurt the environment (by buying rhinoceros horn and shark cartilage). Because bad medicine can injure and kill. Because false beliefs make anti-nuclear protesters attack the wrong targets. Ronald Reagan's Star Wars program was basically a gullible belief in the perfectability of technology, and that gullibility cost billions of dollars. [Congress was told that the system would stop 100% of incoming missiles, and that the system would do this in the very first live test.]
As Stevie Wonder said, superstition's not the way.